Crop Production
Magazine September 2011
Page 8
Pages 28-41
Blackgrass
battle
Combine
choices
How to knock out
the early weeds
Four new users give
their views
Profitable crops through better management
Volume 13 Number 8
September 2011
28
Features
Editor
Tom Allen-Stevens
Sub Editor
Charlotte Lord
Writers
Tom Allen-Stevens
Simon Henley
Martin Rickatson
Mick Roberts
Design and Production
Brooks Design
Advertisement Co-ordinator
Peter Walker
Publisher
Angus McKirdy
CPM Crop Production Magazine
Editorial & Advertising Sales
White House Barn, Hanwood, Shrewsbury,
Shropshire. SY5 8LP
Tel: (01743) 861122
E-mail: [email protected]
Reader Registration Hotline
01728 622521
Advertising Copy
Brooks Design,
Scotts Mansion, 24 Claremont Hill,
Shrewsbury, Shropshire. SY1 1RD
Tel: (01743) 244403
Fax: (01743) 244365
E-mail: [email protected]
4 Talking Tilth
42 Mucking up the value
of straw
A word from the editor
6
Smith’s Soapbox
Views and opinions from an Essex
peasant…..
Rising fertiliser prices, and straw worth
more off the field that on it, have put
the value of manures, composts and
wastes in a whole new light.
20 High horsepower
treads best on tyres
The latest tyre technology, and
a focus on shallow cultivations,
allow one Warwicks farm business
to run wheeled rather than tracked
high-hp tractors for crop establishment,
with the advantage of lower
operating costs.
8 Stack the odds in
your favour
In a year when so much pressure is
piled on to early autumn management,
it may take more than a well stacked
pre-emergence herbicide mix to
vanquish blackgrass.
16 Clear solutions to
tackle OSR weeds
28 A significant
step forward?
The Claas Lexion 770 has the same
power output, threshing system and
grain-tank size as its 600 predecessor.
So where does its claimed extra
output come from? CPM speaks
to two early users.
Poor weed control in oilseed rape
is earning it a reputation as a dirty
crop, while the herbicides used suffer
scrutiny in drinking water. CPM finds
out how to clean up both crop and
watercourse.
34 Making tracks to
CPM Volume 13 No 8. Editorial, advertising and sales offices are at
White House Barn, Hanwood, Shrewsbury SY5 8LP.
Tel: (01743) 861122. CPM is published nine times a year by
CPM Ltd and is available free of charge to qualifying farmers
and farm managers in the United Kingdom.
In no way does CPM Ltd endorse, notarise or concur with any
of the advice, recommendations or prescriptions reported in the
magazine. If you are unsure about which recommendations to
follow, please consult a professional agronomist. Always read the
label. Use pesticides safely. CPM Ltd is not responsible for loss or
damage to any unsolicited material, including photographs.
controlled traffic
system
24 Be on guard for phoma
A pre-production John Deere S690i
combine, equipped with the firm’s
new tracks, is a key component in
a Lincs farm’s move into controlled
traffic farming.
The importance of oilseed rape as a
national crop means a robust disease
control strategy is vital. CPM quizzes
the UK’s top expert Dr Peter Gladders
on phoma and light leaf spot.
and light leaf spot
38 Harvester headway
It’s not just the size of the New Holland
CR9090 that brings an output boost,
it’s the technology the combine has
on board, says one Warwicks grower.
24
Crop Production Magazine –– September 2011
3
Talking Tilth
a word from the Editor
September smells
different
To most people it’s probably too subtle
to notice. But to those who work the
land there’s a real significance to that
distinctive earthiness of freshly turned
soil, brought to life with the early morning
dew and lingering cool dampness: it’s a
new cropping year, a fresh start, a blank
canvas and another chance to grow
some stunningly successful crops.
It’s a new start for CPM, too, with
a new editor. Taking on this role is a
humbling experience –– the magazine
has a very good reputation, earned
entirely through its high quality editorial.
Anything an editor did that could
jeopardise that would betray the loyalty
of a very discerning readership.
Because, as a reader of CPM myself,
I feel the time you put in to reading
something should be rewarded. The more
time you commit, the greater that reward.
Some reader surveys show that
farming magazines are read in any
number of different places. But CPM
is not a magazine to flick through glibly
in the downstairs loo. I’d prefer to think
I’m not draped over your left thigh at the
moment. I’d hope instead that I’m lying
on the desk in your office, or on the
kitchen table. Perhaps I’m even perched
upright on your chest as you lie in bed
reading CPM.
The fact is that, in an increasingly
busy life, you make time for the
things that will bring a reward, and
woe betides anyone or anything
that misuses any precious time
you invest. It’s why I’ve always
read CPM but throw some others
in the bin.
So what rewards will this September
issue bring? Well it marries two aims:
firstly that we’ll bring to the surface some
of those key issues that are critical for
establishing a successful crop. We’ve
asked the questions that need to be
asked and directed them at those who
ought to have the answers.
Secondly solutions to those issues
–– we’ve researched, delved, queried
and pursued and I hope you’ll find within
these pages the nuggets you won’t find
elsewhere. There’s no prescriptive advice
or magic bullets. But there are ideas ––
simple approaches that others are taking
or trying, new research findings that just
make you think.
Take blackgrass control, for instance
–– you’ll have heard already about
stacking your pre-emergence herbicide.
You’ll know that resistance to Atlantis
(mesosulfuron+ iodosulfuron) is building
and that stale seedbeds won’t have
been as successful this year as they
were last autumn.
But how do you translate these
concerns into a robust, stacked
pre-em? And how high can you
stack it before the whole thing
topples over? Even if the chemical
is already in your store, don’t put
it in the sprayer until you’ve read
our in-depth guide (p8).
Then there’s oilseed rape herbicides.
Anyone will tell you it’s different chemistry.
But what does that mean in terms of how
you actually use it to best effect (p16)?
No doubt you’re now up to speed on the
financial implications of your decision to
bale all your straw. But haven’t you ever
wondered about the myriad ways there
are now of returning lost nutrients and
organic matter to your soil (p42)?
And with the crop in the barn, it’s time
to reflect on your most costly piece of
kit –– the combine. You’ll have heard
of auto-guidance, variflow tables and
intelligent harvesting systems. But how
do these bring you increased output,
timeliness and a smoother harvest?
We’ve brought together no fewer than
four user stories to really put these
issues into perspective (starts p28).
Then just what is the benefit of
spraying for phoma (p24)? If you put
your high-horsepower tractor on tyres,
rather than tracks, would it lower your
operating costs (p20)? There are so
many questions, we can only try and
prioritise those that are most important
to your business. But it’s because you
seek answers to these questions that
you transform that earthy-smelling soil
into rich abundant life.
So take a deep breath and relish
that smell –– it’s opportunity, and
we’ve got around twelve beautiful
months to turn that opportunity into
barn-busting success.
Tom Allen-Stevens has a 170ha farm
in Oxon, where September doesn’t
smell quite so good because he’s just
spread several hundred tonnes of
biosolids on the variable soils that
need to be coaxed and coerced
into producing half-decent yields
of combinable crops.
[email protected]
Katamaran (metazachlor+ quinmerac) goes on to DK Cabernet oilseed rape in peerless
conditions. It’s a good start, but we’re bracing ourselves for resistant blackgrass,
drought-prone areas, rabbits and pigeons. So I won’t count my returns just yet…
4 Crop Production Magazine –– September 2011
Smith’s Soapbox
by Guy Smith
Day-dreaming
about Dacian
Some men, I’m told, can chart their past
lives by reference to the girlfriends, wives
and mistresses they had at the time. In
contrast, and rather sadly, with me its
wheat varieties, tractor models and EU
Farm Ministers.
So while some may spend their days
wistfully recollecting the fun they had
with femme fatales called names like
‘loose-lips Lucy’ or ‘dirty Cath’, for me it’s
flashbacks of men like Ray ‘spud-face’
MacSharry or Franz ‘fungus-features’
Fischler.
MacSharry was a particular tease when
it came to proposing CAP reform in the
early 1990s. The Irishman was suggesting
a form of capping that took aid away from
anyone who farmed more than the EU
farm size average –– 30ha.
There was also talk of production
quotas or set-aside rates of over 15%.
I recollect at the time it seemed shrewd
not to even consider buying more land
–– after all it was at the crazy price of
nearly £1500/acre at the time.
The MacSharry reforms were brought
in with a sense of foreboding and I was
doubtful my relationship with the CAP
would stay as happy as it had been in
the 1980s. It seemed times were about
to get tough for arable farming.
What actually happened was the
opposite. The capping proposals were
abandoned at the last minute, then the
pound fell out of bed on Black Wednesday
thus inflating the newly introduced IACS
payments to generous levels. Then the
wheat price climbed 50% and the
set-aside level fell to 5%.
By the mid-’90s we felt we had never
had it so good. The only bad memory
engendered by the name MacSharry was
the recollection that I had turned down
a neighbouring farm that eventually went
for £1350/acre.
Twenty years on and there’s a new
man on the scene, playing with my
mind, and his name is Dacian. Again the
question is should we try to pre-empt
his forthcoming 2013 reforms by
taking decisions now or should we wait
so we can see exactly what the new CAP
will look like?
The proposal to cap support payments
at around £150,000 sounds very sensible
to me. This is partly because I firmly
believe it iniquitous that large farmers
should receive such significant amounts
of CAP money. But the main reason why
I think £150,000 is a fair cut-off point
is because my payments are not far
below that figure.
If someone proposed capping at
£75,000 then I would find that truly
outrageous. This ‘looking after number
one syndrome’ also informs my views
on limiting CAP payments to ‘active’
farmers. It’s a good idea until someone
suggests a definition as to what constitutes
an ‘active farmer’. To my mind it’s simple,
CAP payments should be taken away from
farmers less active than me.
The
proposal that probably
animates me most is the 5% ecological
set-aside. At the moment on this farm
we have about 5% of our land out of
production through Entry Level and
Higher Level Stewardship. If my renewals
for these schemes were imminent,
I would think very hard about committing
to anything until the 2013 reform
becomes clearer.
Taking 5% of my farm out of production
makes sense given the size and nature
of my fixed costs, but taking 10% out
significantly upsets the bottom line. The
other cause of worry is the proposed
restrictions on what can be done with
permanent pasture, with the definition
being land that has been grass for five
years. One wonders how much ploughing
of grassland this sort of talk is going to
inspire this autumn?
It reminds me of visiting a farmer
in lower Saxony in Germany who was
ploughing and drilling wheat into
some undrained and hopelessly boggy
river-valley pastures which had never
been ploughed in their history. The
reason he was doing it was because
he wanted to make the land eligible
for a local ‘greening’ scheme that was
about to be introduced that paid farmers
to convert arable land into permanent
pasture.
Anyway, enough of this crystal-ball
gazing, it’s time to get the drill out and
do some proper work. It’s probably far
healthier to spend one’s autumn days
thinking about how best to farm the land
rather than worrying about how best to
farm the system.
Email your comments and ideas to
[email protected]
Dad always used to reckon a good rape stand was one when you regularly stepped on one or
two plants as you walked across the field. I always used to think that was too thin but over
the years as we’ve wound the seed rate down, I’m coming round to his way of thinking
–– maybe I’m just learning to walk in his footsteps.
6 Crop Production Magazine –– September 2011
Weed control
“Later sowing last year led to a high
level of blackgrass control prior to
drilling. Favourable autumn weather gave
good seedbed conditions and resulted in
excellent activity from pre-emergence
herbicides. Together, these made a
huge difference.
“The challenge this year will be to
build on that success, to retain the upper
hand and reap the benefits over the next
few seasons.”
Rising resistance
Stack the odds
in your favour
‘In a year when so much pressure is piled on to
early autumn management, it may take more
than a well stacked pre-emergence herbicide mix
to vanquish blackgrass.’
By Tom Allen-Stevens
‘How high will you stack before
the stack falls over?’
B
8 Crop Production Magazine –– September 2011
Opening salvos
Although the opening salvos in the
blackgrass battle have already been
fired in many fields across the UK,
through the use of stale seedbeds and
cultivations, it could already be 1-0 to
the weed, reports Sarah Cook of ADAS.
“Dormancy is very high this year, so
blackgrass is less likely to germinate
early in the autumn.” The annual analysis
of the dormancy of blackgrass seeds,
carried out by ADAS and funded by
▲
race yourself for a bitter battle
against blackgrass. Control was
helped last year by a series of
good fortunes, and growers will need
to work hard this autumn to recreate
as much of that as possible and retain
the benefit, says James Clarke of
ADAS Boxworth.
The chief concern is how the key
herbicides will perform, with evidence
of increasing resistance to Atlantis
(mesosulfuron+ iodosulfuron).
“Last year, we may’ve seen a slight
exaggeration in the level of control you
could expect from herbicides,” believes
Ron Stobart of NIAB TAG.
“Now, we need a change of mindset.
Growers need a structured plan involving
a range of strategies to tackle blackgrass.
There’s no doubt early investment in
some stacking and sequencing
approaches will help get the best
out of existing herbicides.”
Dick Neale of Hutchinsons agrees
growers should try something new this
autumn. “Blackgrass gets used to what
you throw at it, so ringing the changes is
no bad thing.”
But there’s more to a good stack than
chucking every chemical you’ve got
into the sprayer tank. It must be a
carefully thought-through approach
–– part of an integrated strategy in
which cultural control plays a key part,
maintains Dr Stephen Moss of
Rothamsted Research.
“How high will you stack before the
stack falls over? Once your Atlantis
control slips down, you may need an
unachievably high level of control from
your pre-em, depending on your system.
But if you’re using cultural control
systems as well, you have a lot
more leeway.”
Weed control
season will have germinated during the
weeks following harvest.
“Dry autumns usually result in knobbly
seedbeds. The key thing now will be to
work down those lumps and aim for a
level soil surface to give herbicides the
best chance possible.”
Local conditions
The annual analysis of the dormancy of
blackgrass seeds suggests a late germination
this year.
▲
BASF, found just 23% germination in
the 52 samples collected from across
the UK.
This is lower than recent years, and
suggests not much of the seed shed this
As in previous years, some samples
tested showed lower levels of dormancy
indicating that local conditions were still
a key factor. But there were no obvious
regional differences and blackgrass
germination will be slow this season,
even where adequate moisture is
present, warns ADAS.
This will bring a swing in focus for the
cultural control methods still available to
growers at this late stage. The HGCA
guide, Managing Weeds in the Arable
Rotation, suggests early drilling to
encourage crop competition, rather than
delaying to encourage a blackgrass chit.
Those who suffered a heavy blackgrass
infestation this year are strongly advised
to bury the seed with the plough. But
they also need to be wary of bringing
up large volumes of seed buried in
previous years as this may still be viable.
Drilling at a higher seed rate using a
competitive variety may also help.
Effective cultural control can reduce
resistant populations of blackgrass by
up to 90%, according to Rothamsted
Research. But the dormancy results
suggest there will still be a considerable
population that will need to be tackled in
the crop. So what do we know about the
resistance status of this blackgrass?
“One thing we’ve noticed in recent
years is the increase in cases of
resistance, compared with when
Atlantis was first introduced in 2003,”
says Stephen Moss.
The team at Rothamsted has been
tracking the level of resistance to Atlantis
since the product was launched. Seed
samples collected from random fields in
2002, prior to the herbicide coming on
the market, were compared in screening
assays with samples collected from the
same fields in 2009 and 2010.
“The results from the most recent
samples showed that resistance to
Atlantis was detectable in 50% of fields.
The core components
BASF’s Stewart Woodhead recommends
a three-way mix of Crystal with DFF
Building an autumn blackgrass strategy
without flufenacet would be like launching a
military assault without artillery. Introduced
around 10 years ago, the active forms the
backbone of the pre-emergence approach
recommended by many agronomists.
“Flufenacet is the modern-day isoproturon
replacement,” says Chris Cooksley of
Bayer CropScience. “It performs well on
blackgrass and has useful activity on
ryegrass and brome. It’s not the complete
solution, but it’s the key component of a
pre-em mix.”
To get the best out of it, keep rates high,
bearing in mind that 240g/ha is a full dose.
“Flufenacet is consistent but a key point is
its persistency. It’s okay to put it on when it’s
dry as it’ll hang around until the rain comes.”
This core component is available only in
mixtures, partnered with diflufenican (DFF,
as in Liberator) and pendimethalin (PDM, as
in Crystal). DFF has been a favoured active
in the autumn slot for decades. It needs
moisture to perform and isn’t famed for its
grassweed activity, but does contribute in
this respect and broadens the spectrum of
a mix.
“DFF’s low mobility in the soil and long
half-life mean it lasts, and is particularly
useful in wetter conditions,” notes Stuart Hill
of Makhteshim Agan .
Historically, rates have always been set
quite low –– 1 l/ha of Liberator contains 60g
of DFF –– and a notable feature is its efficacy
at even lower rates. “Now the trend is to
increase that. Agronomists are familiar
with 100g/ha, but you can get an additional
5% activity on blackgrass by raising this
to 125g/ha.”
10 Crop Production Magazine –– September 2011
However, growers should note that its
persistency means there are following crop
restrictions, and rates above 100g/ha are
ill-advised if min-till OSR is due to follow.
PDM is another long-standing favourite
with growers. It has the edge on grassweeds
and is relatively persistent, although it doesn’t
last for as long in the soil as DFF. “It has
0a good residual activity,” says Stewart
Woodhead of BASF. “It sits in the treated
zone and binds on to the soil, and is taken
up by both the shoots and the roots.”
A full single dose is 1320g/ha, although
you can apply 2000g/ha in a season –– a
pre-em dose of PDM is often topped up with
a post-em addition. “Using full rates of some
formulations of PDM can be a lot of cans to
empty and wash. That’s why we introduced
Stomp Aqua, which encapsulates the
formulation. The cans are quicker to rinse
out and it doesn’t stain.”
Growers have traditionally opted for either
Liberator or Crystal. But those who have
stuck to one are strongly encouraged to try
a three-way mix. “We’re recommending
growers add 100g/ha of DFF to Crystal ––
that’s achieving the strongest performance
in our trials,” reports Stewart Woodhead.
Weed control
And although blackgrass infestations
were low in most fields –– meaning
resistance isn’t necessarily obvious
–– these results should start alarm
bells ringing, warning of increasing
problems ahead.”
Worrying trend
Atlantis is reducing year on year. We’re
also finding the same trend with Topik
(clodinafop) and Laser (cycloxydim).
Growers should therefore place less
reliance on the post-emergence herbicide
than they perhaps did in the past.”
So what about the pre-em options?
“Susceptibility to pendimethalin (PDM)
and chlorotoluron (CTU) doesn’t appear to
be changing much. But this is the overall
picture, and there can still be much bigger
changes in individual fields.”
The Rothamsted team has also shown
losses in efficacy of flufenacet (as in
With resistance to Atlantis detected in
50% of fields surveyed by Rothamsted,
there could an unachievable level of
control being asked of pre-em sprays
on some farms.
Crystal and Liberator) as a consequence
of repeated spraying. “But the reductions
are relatively modest so far, and keeping
to full rates of flufenacet-based herbicides
should still form the core of any pre-em
spray strategy.”
There’s only so much the pre-em
▲
There’s also a worrying trend in the
development of enhanced metabolism
resistance (EMR), the commonest type
where plants are able to detoxify the
herbicide to varying degrees. “The level
of resistance conferred by EMR we’re
now seeing to Atlantis is approaching
that of target site resistance (TSR).
This is a surprising finding as with most
herbicides, EMR confers a much lower
degree of resistance than TSR.”
TSR is where a plant blocks the site of
activity of a specific herbicide. ALS TSR
is the less common type of resistance
which allows blackgrass to shrug off
sulfonylurea herbicides, such as Atlantis
and Lexus (flupyrsulfuron), but growers
should be aware that cases are on
the rise.
“Tests we’ve carried out since 2002
show that the level of control provided by
Weed control
Pressure on the pre-em
Control from main
post-emergence
treatment
Target = 90%
(control needed
in ploughing
systems)
Target = 93%
(control needed in
deep-tine systems
+ cultural control)
Target = 97%
(control needed
in deep-tine
systems)
Control required from the pre-emergence herbicides to achieve
the three different overall target levels of control
The better performing pre-emergence mixes
or sequences contain 3-5 active ingredients,
including flufenacet, notes NIAB TAG’s
Ron Stobart.
▲
treatment can be expected to deliver,
however, warns Stephen Moss. “The more
the efficacy of the post-em treatment
drops away, the more you rely on the
pre-em. Stacking can push the level of
99%
0%
0%
0%
89%
9%
36%
73%
79%
52%
67%
86%
69%
68%
77%
90%
59%
76%
83%
93%
49%
80%
86%
94%
achievable
potentially achievable
control up, but how long can you do that?”
The resistance results have been fed
into a model that gives growers an idea
of the level of control required from the
pre-em treatment. This is based on the
unlikely to be achieved
control they can expect from their post-em
treatment, together with the cultivation
regime and cultural control methods
used (see table above).
If ploughing, you need herbicides to
The newcomers
Defy steps up the activity of your pre-em,
says Syngenta’s Iain Hamilton
Now in its fifth year, Defy (prosulfocarb) is
a relatively new addition to the herbicide
toolbox. “It’s a carbamate, related to
tri-allate, which is taken up through the
weed shoot and roots,” says Iain Hamilton
of Syngenta.
Although sold on its own, it should only be
used in mixes, he says. Trials results have
shown a varied performance on blackgrass,
but it’s revered by many agronomists for
what it adds to the mix.
“Its key strengths are a different mode
of action and that it brings in certain
other weeds, like ryegrass and annual
meadowgrass,” continues Iain Hamilton.
“It goes well with both Liberator and Crystal
and a four-way mix also gets good results.
Generally, each step up gets you an extra
10% control.”
It’s middle-of-the-road for persistency and
will last for the autumn window, he adds.
Dose rates tend to be quite varied, with
mixes stretching from 2 l/ha right up to the
full label dose of 5 l/ha.
The big news for Lexus (flupyrsulfuron)
is that it can now precede Atlantis.
The statutory restriction on using two ALS
inhibitors in the same cropping year had
previously kept it out of the pre-em toolbox
for many growers.
Three years’ work by DuPont, including
collaborative studies at ADAS Boxworth,
showed that adding flupyrsulfuron to a
pre-em residual programme improved
blackgrass control in every situation.
“Our 2010 trials gave an average
increase in blackgrass control of 22%,”
reports Dupont’s Alister McRobbie. “In
general, the better the residual pre-em
herbicide was on blackgrass, the lesser
the effect of flupyrsulfuron.”
Growers must be careful how it’s used if
sequencing with Atlantis, he stresses. “It
should be applied at 20g/ha in a tank-mix
12 Crop Production Magazine –– September 2011
with a suitable residual partner –– applied
pre-emergence of any blackgrass.” Growers
would also have to find non-ALS inhibitor
solutions for broadleaf weed control,
he adds.
Dick Neale of Hutchinsons welcomes
the new approval. “Lexus is good –– very
useful in the pre-em position. In our trials,
the sequence with Atlantis enhanced control
in every situation.”
This in itself shows the sequence
shouldn’t increase the likelihood of
resistance developing, he maintains.
“ALS resistance is out there, but it’s post-em.
The pre-em mechanism is different, so it’s
important growers only use it pre-emergence
of the weed.”
But Stephen Moss disagrees. “It’s still
risky. While pre-emergence Lexus is more
effective than post-emergence applications,
and sequences with Atlantis may well
increase the level of control, I don’t accept
that EMR only sets in when the plant is
established.”
Enhanced metabolism to PDM can
be demonstrated in germinating seeds,
he point out. “I see no reason why this
shouldn’t apply to Lexus. The idea that
sequencing two ALS inhibitors doesn’t
increase selection pressure defies logic.
I don’t see how this will reduce the
selection pressure unless pre-em
Lexus replaces an Atlantis application.”
This tells you how much
control you need from your
pre-em, based on the level of
control you can expect from
the post-em.
“Consistently getting over
80% control from pre-ems is
unlikely. So once your Atlantis
control slips below 90%, you
Have you tried…?
Flurtamone with flufenacet
and DFF won’t leave many
holes, assures Bayer’s
Chris Cooksley.
Chlorotoluron (CTU) is around
40 years old but still has a
useful role in the autumn
herbicide programme,
according to Stuart Hill of
MAUK. “Its main strengths are
that it increases blackgrass
control in programmes and
it’s not showing a significant
rise in EMR. CTU in pre-em
trials has added 5-30%
additional activity.”
It also adds activity on
ryegrass and sterile brome.
“It complements DFF in
variable conditions as CTU is
moderately mobile, while DFF
has low mobility.”
The optimum rate is around
1500-2200g/ha and trials
results show it steps up
performance of the core
components of a pre-em mix.
But only about half the wheat
varieties on the HGCA
Recommended List are tolerant
to the herbicide, so growers
should check their varieties
carefully before using it.
Flurtamone is another
active that’s quietly achieved
admirable results in trials.
“It was the original IPU
replacement about 10-12
years ago,” notes Chris
Cooksley. “It’s a mixer first
and foremost and by itself, it’s
not remarkable. But it’ll add
around 10% control to a
flufenacet-based mix.”
It has some activity on
ryegrass and annual
meadowgrass, as well as
some broadleaf weeds.
“A three-way mix with DFF
doesn’t leave many holes.”
Supplied as Movon or Vigon,
this delivers the recommended
120g/ha rate.
Avadex (tri-allate) reaches
the ripe old age of 50 this
year. “It was first sold in glass
demijohns in 1961,” says
Dr Dominic Lamb of Gowan.
Avadex can only be applied
as a granule through a
specialist applicator, so is
currently always in sequence
with other pre-ems. “It dewaxes
and sensitises the blackgrass,
and it helps pretty well any
programme.”
The herbicide works well as
the second part of the pre-em
programme –– the priority is to
get the sprayed pre-em on at
the right timing, so it can fit
in after this if necessary. “It’s
best if it’s applied before the
one-leaf stage of the weed.
Beyond that, you can’t expect
much control.”
A liquid formulation is still
in the approval process and
should be available for growers
by autumn 2012.
▲
provide 90% control to keep
blackgrass populations in
check. If cultural control
methods are practised in a
deep-tine system, the target
rises to 93% control from
the herbicides, while without
cultural control this climbs
further still to 97%.
Weed control
Try something new this year, advises
Hutchinsons’ Dick Neale.
95% control without using Atlantis,”
reports Ron Stobart.
Numbers game
▲
need an unachievably high level of
control from your pre-em in a deep-tine
based cultivation system. Where cultural
methods or ploughing are used in
addition to that, control from Atlantis
can slip to 50-70% before pre-em
applications fail to compensate.
“So pre-em herbicides, combined
with cultural control methods, can
help compensate for the declining
performance of Atlantis. But how
sustainable is this in the longer term?”
HGCA-funded work, carried out through
NIAB TAG and SAC, backs this up.
“We looked at stacking and sequencing
approaches that would deliver more than
A range of different approaches were
trialled over four seasons, with the
blackgrass population density ranging
from around 50 heads/m2 to over 1800
on the different trial sites.
“Essentially, it’s a numbers game.
Generally speaking, high levels of control
from these treatments are only being
achieved at populations lower than
100 heads/m2. In high blackgrass
situations, you need to be including
cultural control in your overall strategy to
bring populations down to a level that’s
achievable for the pre-em.”
The trials pitched the main pre-em
ingredients against each other on their
own, at the pre-em, peri-emergence and
early post-em timings, and then in mixes
and sequences. “Stacks and sequences
generally performed far better than the
products on their own, but we didn’t see
a big difference between stacking or
sequencing, which allows growers
a bit more flexibility.
“Moreover, the better performing
programmes typically used around 3-5
active ingredients and tended to include
flufenacet. Conditions at application are
also important, with a fine, moist soil
surface helping to maximise the level
of performance.”
One result in particular illustrated how
effective a mix of actives could be (see
chart opposite). Resistance to Atlantis had
been confirmed at the Great Carlton site in
Lincs. “The trial showed how incrementally
building up a stack or sequence can
improve the level of control.”
Poor control
But it also showed how the farm’s
standard approach –– Liberator+ Defy
(prosulfocarb) followed by Atlantis –– can
deliver a very poor result in a resistant
situation. “In this case, the best mix
didn’t include flufenacet, but did have
a range of actives. It shows the value
in looking for alternative chemistry,
although you’d still not be happy returning
59 heads/m2, so additional cultural control
options would need to be considered
seriously in this scenario.”
Dick Neale of Hutchinsons points out
there are some fundamentals to get right
before choosing what to put in the spray
tank. “You must ensure you prepare the
seedbed for the pre-em –– the drilling
depth is critical, with 32mm being ideal.
14 Crop Production Magazine –– September 2011
Weed control
A lot of growers haven’t used Avadex for
some time and there can be serious
problems where it’s used if the crop
isn’t drilled correctly.”
Timing is also important. “The key is
the word ‘pre’. You get a far better result
if you apply it before the weed seeds
start to germinate. You need moisture
for it to work, but you should still apply
it even if it’s dry.”
Staggering difference
Try something new is the mantra with
mixes or sequences, keeping flufenacet
as the key ingredient. “Whether this is
provided through Crystal or Liberator, it
doesn’t really matter,” says Dick Neale.
“But think about what active you may
be relying too heavily on.”
PDM is a good example –– it may
have been in use for many years across
the rotation and sensitivity could now be
waning, he notes. “You find trials and
situations where Liberator performs
better, but equally where the opposite
is true.”
When adding to the 3 core components,
flurtamone is a strong contender. “It’s
amazing what it does if you add it to the
mix. If all you’ve been using is Crystal
for the past 8/9 years, you’ll probably
be staggered at the difference.”
He recommends the full 120g/ha rate
provided with Vigon (diflufenican+
flufenacet+ flurtamone) to bring an
extra 10% control.
Keep rates high with Defy too, he
stresses. “At 2 l/ha, there might be
antagonism with PDM, for instance, but
at 4 l/ha, it transforms the level of control.
It’s expensive but it’s worth it and can
bring an extra 20-25% control.”
Bringing diflufenican into a Crystal mix,
PDM into Liberator or introducing CTU
are also good options that build in useful
additional blackgrass control, he says.
“A very effective approach is to use a
sequence –– go with 0.6l/ha of Liberator
then follow with a peri-emergence, 2 l/ha
dose of Crystal, for example. This takes
the flufenacet rate up to 360g/ha, but it’s
critical that the follow-up treatment takes
place within 14 days.” ■
HGCA-funded blackgrass study at Great Carlton, Lincs
(confirmed resistance to Atlantis)
LSD 128; CTU used at 1500g/ha; yellow bar shows standard farm treatment
Crop Production Magazine –– September 2011
15
Weed control
Clear solutions to
tackle OSR weeds
Poor weed control in oilseed rape is earning it a
reputation as a dirty crop, while the herbicides
used suffer scrutiny in drinking water. CPM finds
out how to clean up both crop and watercourse.
By Tom Allen-Stevens
‘Crop safety and stewardship go
hand-in-hand with timeliness.’
n oilseed rape, weed control goes far
beyond simply controlling weeds, say
many agronomists. It has much more
to do with how the weed is handled
across the rotation and the nature of the
herbicides used. The key question to ask
now is whether it’s the herbicide that
should change, or the way it’s used.
“Once a crop is established, blackgrass
is less of a yield robber in rape than in
cereals,” observes Jon Bellamy of NIAB
TAG. “But carbetamide and propyzamide
are our one chance in the rotation to tackle
the weed without building resistance
selection. That’s why it’s absolutely
crucial to get at least 95% control.”
I
Sadly, however, few growers are achieving
this. “Using straight propyzamide or
carbetamide on their own, we’re not getting
the levels of control we need to stand still
with blackgrass. Growers are typically
achieving about the mid-80s. We need
to push it 10% higher.”
But it’s a challenge. Testing, which
helps to identify problems, suggests most
blackgrass is now resistant to foliar-acting
graminicides, such as cycloxydim (as in
Laser), propaquizafop (as in Falcon) and
tepraloxydim (as in Aramo). This gives the
weed a gaping window in which to thrive,
notes Dick Neale of Hutchinsons.
“In oilseed rape, we rarely have the
option of using a stale seedbed, then
propyzamide isn’t applied until the
end of Oct at the earliest. That’s a long
time after you drilled the crop and
applied the pre-emergence herbicide.
16 Crop Production Magazine –– September 2011
We need an alternative way to hold the
weed –– Falcon and Aramo can be a
bit hit-and-miss.”
Lawns of blackgrass
Last year was a case in point, with
favourable conditions for blackgrass
to germinate in early autumn, recalls
Stuart Hill of Makhteshim Agan. “A lot of
growers were facing lawns of blackgrass
–– the graminicides just didn’t work. So
we saw a change of approach with many
applying a dose of carbetamide early, or
mixing some in with their propyzamide.”
It’s a practice that’s gaining favour,
and one that’s backed up through a
number of independent trials. “Typically,
you’d apply a relatively low dose of
carbetamide –– about 2.5kg/ha –– in
early to mid-Oct, and this would replace
the tepraloxydim application. It costs
about the same as Aramo and often
does a better job,” claims Stuart Hill.
Trials in Lincs last year, with an
untreated blackgrass population of
550 plants/m2, achieved 67% and 82%
control with full rate carbetamide and
propyzamide respectively when each
were applied at the mid-Nov timing,
he continues. “A mid-Oct dose of
tepraloxydim boosted the carbetamide
control by only 1-2% but 2.5kg/ha
Weed control
tank-mix if you miss the Oct
timing or if you drilled late and
the crop isn’t big enough until
Nov,” advises Stuart Hill.
The approach makes sense,
agrees Jon Bellamy. “There’s a
lot more stacking of herbicides
going on in cereals, so why
not in oilseed rape?” But this
is not something to rush into,
he cautions.
Water issue
A reduced rate of carbetamide
in October can bring better
results, says Makhteshim Agan’s
Stuart Hill.
▲
carbetamide, followed by
full-rate propyzamide, achieved
92% control.”
The carbetamide does the
holding job that the fops and
dims used to manage, explains
Stuart Hill. “It’s mainly rootacting with some shoot uptake
as well, and at this early timing
when the blackgrass is small,
then 2.5kg/ha has been enough
to begin the herbicidal activity.”
The essential element is
then to follow up with the
propyzamide within 4 weeks,
he stresses. “What you’re doing
is getting the blackgrass ready
for the second application
which really nails it.”
The maximum 4-week
gap is critical, he believes.
Trials results show carbetamide
is rarely as effective as
propyzamide on blackgrass,
even when used at its full dose
at the more usual timing in
early Nov. “The early dose is
going on in warmer conditions
and consequently will break
down more quickly. The aim
is to start the process off by
sensitising the blackgrass.
If you don’t come back in 3-4
weeks after the first application,
the blackgrass may start to
regrow and you’ll be back to
square one.”
The propyzamide is then
applied at full dose at the usual,
early November timing. “The
variance to this sequence is to
mix the carbetamide in with the
propyzamide. But the sequence
approach is better –– only
“I’d be slightly concerned about
putting carbetamide onto small
plants in Oct –– it could check
the crop. You also need to think
about the water issue. That’s a
lot of active ingredient of the
two chemicals that’ve been
detected in water, so they’d
need to be used wisely.”
Much more relevant to
success with propyzamide,
and giving a greater chance
of achieving 95+% control, is
how you’ve managed the soil
since harvest, he says.
“Most important is not
to move too much soil.
You’re looking to keep the
blackgrass in the top half
inch where you can control
it with propyzamide.”
The aim during cultivations is
to keep the weed seed as close
as possible to the surface
where it fell when it was shed.
“Direct drilling ensures this and
the blackgrass control you can
achieve when Autocasting is
fantastic,” says Jon Bellamy.
“But anything more than light
discing puts the blackgrass
roots out of reach of the
propyzamide.”
Stuart Jackson of Dow
AgroSciences confirms this.
“The deeper the soil movement
and the more you move the
soil, the more variable the
performance of propyzamide.
If you go any deeper than 5cm,
the blackgrass germinates from
below the propyzamide layer
and comes through unaffected.”
Trials at a high-population
blackgrass site back this up.
The plots at Poundon, Bucks,
were either given shallow
cultivations or ploughed.
In the shallow-cultivated plots,
Crop Production Magazine –– September 2011
17
Weed control
Keep the blackgrass seed as close to the
surface as possible, advises Dow’s
Stuart Jackson.
▲
there were 1688 blackgrass plants/m2 in
the untreated plots, compared with 452 in
the ploughed plots.
“So there was a significant reduction
through ploughing. But when the
propyzamide was applied, it achieved
only 85% control of what was left in the
ploughed plots, compared with 99%
control in the shallow plots.” Overall just
17 plants/m2 were left in the shallow
plots, compared with 68 where ploughed.
The spray timing is the next key
consideration, maintains Stuart Jackson.
“You want a moist, cool soil –– less than
10°C. Typically that’s around Guy Fawkes
night, but don’t get hung up on the date
–– go when it’s right. If it’s too warm, you
won’t get the required level of persistency.”
The final consideration is the dose, he
says. “You need the full 2.1 l/ha rate to get
a consistent performance.” But rather
than mixes or sequences with carbetamide
or tepraloxydim, he favours adding some
cycloxydim. “We’re finding this boosts
blackgrass control by around 4-6%.”
Dick Neale reckons there’s no one
approach that fits all situations. “It’s horses
for courses.”
In Hutchinsons trials last year, two
different establishment techniques were
compared for blackgrass control across
a range of treatments (see figure opposite).
“The subsoiler-cast plots opened up the
soil to depth and gave the blackgrass
greater opportunity to put roots down.
It grew quicker and more vigorously than
in the direct-drilled plots.”
Where straight propyzamide was used,
there was very little difference between the
two systems. “There was a reasonably
high level of control, although not enough
overall. Including propyzamide is absolutely
vital –– where it was omitted, we got very
poor control.”
The best results were from plots which
had included an Oct dose of tepraloxydim.
“The host farmer of the site had dropped
Aramo following years of poor control, yet
when we tested the blackgrass, we found
it was sensitive to the herbicide in 2010.
It did add 7-8% control, giving us a very
Harnessing the herbicide
David Felce is trying several different
approaches
Cambs grower David Felce has been
keeping one eye on the weather this autumn.
“There was some very heavy rain forecast
at drilling, so we decided to delay the
metazachlor. We’re careful to drill to the
right depth but didn’t want to risk any crop
damage all the same, and we certainly didn’t
want herbicide to end up down the drains.”
Farming 280ha in a contract-farming
arrangement near St Neots with
David and Stephen Ellerbeck, he also
provides agronomy advice and procures
agrochemicals and fertilisers for Midloe
Farmlink –– a group of half a dozen farms
amounting to around 2000ha. This year, their
own oilseed rape crop extends to 40ha of
Cabernet with 40ha Alienor, which is “early
and easy to manage” and Extrovert, a new
hybrid with “incredible” early vigour, he says.
There is also a small trial of a new
conventional variety –– ES Agatha.
At the time of writing, the plan was to
apply metazachlor post-emergence of the
crop. “You can go when the cotyledons have
expanded but it’s crucial that you apply it
before any weeds have emerged. It’s a
compromise, but crop safety and stewardship
go hand-in-hand with timeliness.”
After a relatively dry year to date,
David Felce is expecting “a fair dollup” of
winter rain. So it’s been even more important
to ensure the seed has good soil cover.
“Where a subsoiler seeder has been used,
we’ve been careful to go in afterwards with
a press or power harrow.”
Restrictions on clopyralid have added
complications to broadleaf weed control.
The straight active (e.g. Dow Shield) has lost
its approval for use in the autumn as traces
of it have been found in water. Until new
chemistry arrives (expected before autumn
2012), mixtures, such as Galera (clopyralid+
picloram), can still be used.
“As for blackgrass, we’re trying several
different approaches. We’re going to go on
to some fields at a very early stage ––
1-2 leaves of blackgrass –– with 1 l/ha
Aramo (tepraloxydim). This will be applied
where we know the resistance status will
still allow control. The big advantage of
going early is that you catch the blackgrass
before any enhanced metabolism resistance
sets in.”
He’s also found good results from buffering,
so plans to add a water conditioner to stop
the hardness locking up the chemical.
“On fields where blackgrass is very bad,
we’ll be applying a reduced rate of Crawler
(carbetamide) in Oct. We found 2.5kg/ha
18 Crop Production Magazine –– September 2011
worked extremely well last year, taking out
that early flush. We’ll then follow in early Nov
with our standard 2.1 l/ha Kerb (propyzamide)
and 0.5-0.75 l/ha Falcon (propaquizafop). The
graminicide helps deliver a consistent kill.”
He also bears cultivation strategy in mind
when deciding herbicides. “Crawler’s more
mobile, so where we’ve worked the soil to a
greater depth, we tend to get a better result.
But where the soil has been disturbed to a
lesser extent, Kerb does better.”
And stewardship is a key consideration.
As a LEAF (Linking Environment and
Farming) demonstration farmer, David Felce
has been involved in the Sustainable
Drainage System (SuDS) project, run jointly
by LEAF and the Environment Agency. The
project looks at practical solutions to limit the
loss of key pesticides to water courses.
“It’s a problem because ideal conditions
for applying Kerb and Crawler are when
they’re more likely to be washed away.”
As part of the project, 6m grass buffer
zones have been enhanced. “We’ve stepped
up their effectiveness by establishing
tussocky grass species. A further step up
in gateways and near steep slopes has been
to create a mound in the buffer strip.”
Losses through drains are almost
impossible to prevent, but various ways to
slow down the sediment flow in ditches and
keep losses from leaving the farm have
been under investigation. “There’s huge
promise through using reed beds or willow.
We’re hoping for more funding so that we
can take this work forward.”
Weed control
high, sustainable level of blackgrass
kill overall.
“This shows how important it is to get
your blackgrass tested annually and then
adapt your programme to suit.”
Where carbetamide preceded
propyzamide, good control was achieved
where the plots had been direct drilled,
but relatively poor results were achieved
on the subsoiler-cast plots, he continues.
“You mustn’t allow the blackgrass to root
to depth too quickly. The lower roots
reinvigorate the plant and it grows away
unaffected by the early residual.”
Where a mixture was applied in
Nov, rather than a sequence, the good
control achieved could be misleading,
notes Dick Neale. “What the results don’t
tell you is the state of the crop. The
blackgrass was really competing with the
rape and it was hammered. This shows
that a sequence is absolutely key in
high-blackgrass situations.”
Crop competition itself is also a key
factor in achieving good control, notes
Jon Bellamy. “Many growers worry that the
propyzamide will be less effective if there’s
a good level of crop cover, but this doesn’t
tend to be the case. The herbicide finds
its way to the soil, while the crop cover
smothers the blackgrass.”
One aspect to consider is tank-mixing
in a fungicide treatment, points out Stuart
Jackson. “For propyzamide, it’s almost
best if there’s a bit of dew on the leaves
and the spray washes off and onto the
ground. But you’ll still want your fungicide
to stick to the leaf.”
However, good stewardship is vital,
stresses Jon Bellamy. He knows this more
than most, being an agronomist in the
Cherwell Valley catchment. This is the
only area in England designated as a
target catchment as a result of pesticide
exceedences (rather than phosphate in
every other case).
“It really is a problem in oilseed rape,
with metazachlor, carbetamide and
propyzamide all being detected and
there’s no easy answer. But if we lose
these herbicides, weed control in rape
will be practically impossible.”
Water-flow research
Studies at Loddington, Leics, and Cockle
Park near Newcastle have shed light on
how propyzamide moves to watercourses,
reveals Stuart Jackson. “At Loddington,
80% of the total pesticide content in the
water came through the drains. But the
concentration in surface run-off was
generally 3 times as high.”
Run-off from a 3° slope was monitored
from min-tilled and ploughed systems,
comparing no field margin with a bare
buffer zone and a grass margin. The
results showed the cultivation system
made little difference. But over 8 times as
much pesticide ran into the watercourse
where there was no margin, compared
with the grass buffer.
“If you don’t have a grass margin, just
shutting off the outside 6m of the spray
boom makes a huge difference,” notes
Stuart Jackson.
The drain-water studies pitched a
ploughed system against deep-tine and
shallow cultivations. Peak flows and total
dose lost were both monitored. “The
pesticide run-off concentrations during a
peak flow from the ploughed plots were
2.5 times as much as those from the
shallow cultivations, while the deep tine
lost twice as much.”
Nor is this movement through the soil
in a ploughed or deep-tine system going to
help control deep-rooted blackgrass, he
says. “The amounts that wash down are
too small to be effective as a herbicide, but
can be enough to trigger a drinking-water
exceedence.”
The study at Loddington showed four-fifths
of total pesticide content lost from the field
runs out through drains.
Overall, 2.5% of the applied dose was
picked up in drainage water from the
ploughed plots, compared with 2.4% in
the deep-tine and just 1.4% in the shallow
cultivations. “You lose less from shallow
cultivations and it irons out the peaks,”
concludes Stuart Jackson. ■
Stewardship best practice
To minimise propyzamide, carbetamide
and metazachlor losses into watercourses:
●
Establish a grass margin of at least
6m between field and watercourse
●
If a margin doesn’t exist, switch off
out section of spray boom when
passing near a watercourse
●
Keep cultivations shallow –– the less
soil disturbance, the better
●
If subsoiling or subsoiler casting, roll
afterwards to close up the fissures
●
Don’t spray when the ground is frozen
●
Don’t spray when heavy rainfall
is forecast
●
Try to avoid spraying when soils are
wet and the drains flowing
●
If ground is cracked, wait until there’s
enough moisture in the soil to close
up fissures
Hutchinsons oilseed rape herbicide trials 2010
It’s horses for courses, says Hutchinsons’
Dick Neale.
Crop Production Magazine –– September 2011
19
High horsepower treads
best on tyres
The latest tyre technology, and a focus on shallow
cultivations, allow one Warwicks farm business to
run wheeled rather than tracked high-hp tractors
for crop establishment –– with the advantage of
lower operating costs.
By Martin Rickatson
‘A properly tyred and weighted
wheeled tractor is a match for
an equivalent crawler.’
peed is the key consideration
for William Corbett Farms, based
at Orton-on-the-Hill, Warwick.
A pair of ploughs is retained in its
machinery fleet, but deep tillage is
practised only as necessary across
the considerable acreage farmed.
The ploughs are used rotationally as part
of a grassweed control strategy to keep
brome and blackgrass in check, while
subsoiling is carried out only where
there’s an obvious need.
Otherwise, the majority of the business’
cereal seedbed creation –– with a large
part of its cropping being continuous
S
wheat –– is carried out using relatively
simple tine-based combination cultivators
working at shallow depth ahead of a
Horsch CO tine drill. Coupled with big
field sizes, this allows the Corbetts to
use high horsepower to cultivate with
wide implements at high speed.
“That’s one of the main reasons we
favour wheeled rather than tracked
machines for tillage,” says Chris Corbett,
who farms with his father, David.
“A crawler is undoubtedly the best
machine to have up front for deep
cultivations, but we try and do as little of
that as possible. For the shallow system
that we primarily work to, we’ve found
a properly tyred and weighted wheeled
tractor is a match for an equivalent
crawler –– but with a much lower initial
purchase price and with far lower
running costs.
20 Crop Production Magazine –– September 2011
“And a wheeled tractor is much better
suited to working with a drill, where
a tracked machine –– especially a
twin-track one –– can cause headland
compaction and smearing when turning.”
The business first ran a wheeled
tractor as its prime mover twenty years
ago, in the form of a 325hp Steiger
Panther supplied by nearby importer
Offchurch Tractors. But there were
issues with its manual transmission, as
well as the difficulty of moving the tractor
on dual 650mm wide tyres –– at that
time, the only real option available for
this type of machine.
Flexibility
“Conventional wheeled tractors were
getting larger back then, and we replaced
the machine with three 250hp Case IH
Magnum 7250s, fitted with the then-new
710 tyres. This gave us more flexibility,
but of course we needed more operators.
With four staff, though, who also work out
of season on our plastic recycling and
building businesses, having sufficient
operators wasn’t a problem.”
Soon after that, Steiger articulated
tractors were re-introduced to the
UK market in the mid-’90s, alongside
their Quadtrac equivalents, under new
owner Case IH. This led the Corbetts to
reconsider the idea of running fewer,
machine width beyond 3m. Alongside
this has come the ability to operate
across a range of tyre pressures,
depending on the type of work being
carried out, the tractor’s weight and its
travel speed.
Lower cost
A purchase price around £60,000 ––
lower in 2004 than the equivalent
tracklayer –– also weighed in the
machine’s favour. Plus there was the
prospect of lower maintenance costs
as there are no idlers, bearings and
associated running gear. And there was
also the ability to travel on the road in
comfort and at reasonable speed without
transport width concerns.
“Initially, though, we came up against
some difficulties in sourcing what we
wanted,” recalls Chris Corbett. “Although
Case IH had previously supplied wheeled
articulated machines on special order, at
the time when we enquired about one
back in 2004, the company was focusing
on the Quadtrac in this power bracket.
Believing that demand for wheeled units
would be too small to justify importing
them, initially Case IH was unable to
help us.
Wheeled tractors are well-suited to
shallow, high-speed cultivations,
reckons Chris Corbett.
“But we told them why we were looking
for this type of machine, because of
the nature of the work we wanted to
do with it. So they agreed to supply
us with a 375hp STX375, which we
ordered on slave wheels so we could
then determine the best type of tyre
equipment for our needs.”
▲
higher-hp machines for their primary
cultivations –– particularly as the tractors
offered improved ease of operation,
with full powershift transmissions.
“We tend to buy new, but only retain
our tractors for as long as they’re
trouble-free. Our plan at the time was to
move the Magnums down the fleet, and
look at running a larger machine with
wider equipment for the main tasks,”
explains Chris Corbett. “However, tyre
equipment was still an issue. While
super singles were available, we didn’t
feel we could get the combination of
ground contact and transport width we
wanted, so we put the idea to one side.”
But more recently, there have been
significant developments in the tyre
equipment available for articulated
tractors. These have come alongside the
latest generation of the machines to be
offered to the UK market by the likes
of John Deere and New Holland, as
well as Case IH.
Among the key advances have been
flexible sidewalls that reduce rolling
resistance, improve performances at higher
speeds, and offer a longer and wider
footprint. The result is a reduction in soil
compaction without stretching the overall
would be required to do, Trelleborg
agreed to equip and guarantee for five
years a set of single 850/60 R38 Twin
414 tyres for the STX375. What’s more,
the tyres would be fitted to the firm’s
solid wheel centres, to ensure the two
were power-matched.
Low wheelslip
Correct ballasting with nose weights is
important so that a 60:40 balance turns
into a 50:50 split when at work.
▲
But discussions with a number of the
major tyre manufacturers came to a fairly
swift conclusion when the Corbetts
revealed the size of tractor they were
dealing with.
“We initially agreed with one
manufacturer to purchase a set of
900mm tyres for the tractor, only to
discover later that they wouldn’t warrant
them –– they’d only stand behind dual
650mm tyres on a 375hp artic. But we’d
been there already with our Steiger
Panther, and we didn’t want the hassle
of running duals again.”
Then the Corbetts started discussions
with tyre manufacturer Trelleborg. Once
they’d established how the tractor would
be operated and the type of work it
The STX375HD tractor arrived in time
for autumn 2004, and was fitted on-farm
with the cross-ply Twin 414 tyres. “Once
our tractor arrived, we were more than
happy with its performance. Even on
subsoiling, it was running happily in 3-4th
gear at just 2-3% slip. The only time we
found wheelslip to be significantly higher
than this was when the ground was really
wet. But that’s when it’s time to stop,
whatever the tractor type.”
While the technology has been largely
superseded in many tyre formats, cross-ply
construction is still reckoned to have
some advantages for this type of high-hp
tractor –– the strong sidewalls it creates
are very efficient at transferring power.
But for the shallow cultivations
preferred by the Corbetts, the ground
contact area is as important as traction.
So when the family decided to add
another wheeled artic to its fleet four years
ago to speed up its autumn operations,
they looked to Trelleborg’s improved
TM900 tyre.
This is a radial tyre that offers greater
section width and a taller diameter,
according to the company. That partly
accounts for the greater ground contact,
but what’s also responsible is an improved
sidewall design that allows greater flexibility
and the ability to operate effectively at a
range of pressures, depending on the
weight of the machine, its speed and
the job it’s doing.
The result, depending on the tyre
pressure, is less rolling resistance,
better performance at higher speed, a
bigger and flatter footprint, and less soil
compaction. So when the Corbetts
ordered a second Steiger, a 435hp 435
model, in 2010, it was specified with
TM900 tyres, in 900/60 R38 format.
“Initially, we were disappointed with
the tractor’s grip but on Trelleborg’s
advice, we reduced the tyre pressure
Rotational ploughing is carried out to keep
a lid on grassweeds with an 11f reversible
plough behind 1 of the Steigers.
The wheeled-only approach
New Holland chooses to focus exclusively
on tyres with its articulated tractor range,
and launched a new line of T9 machines
last season. The firm’s high-hp tractor
specialist, Richard Hollins, says NH has
worked closely with Trelleborg on featuring
the right tyre equipment on the new models.
“We have one customer who runs a
350hp New Holland T9050 alongside a
pivot-steer tracked machine, because there
are some tasks he feels are better suited to
the wheeled tractor,” he says.
“Some of that depends on the soil type
and moisture content, while the type of work
is another factor. Tracks work well if it’s very
wet or very dry, says the customer, but for
80% of the time, in 80% of conditions,
wheels are a better option, being more
fuel efficient and more productive.
“For another customer on limestone
soils in Notts, the issue is more about
running-gear damage, with the high
likelihood of stones getting in-between
the tracks and the idlers or drive wheels.
He’s also working at higher speeds of
at least 12km/h, and reckons there’s little
difference in performance between his
tractor and a comparable crawler. But
running costs are considerably lower.”
Rounded shoulder
Michelin’s MachXbib radial, the
firm’s key high-hp tractor tyre,
features a rounded shoulder
design claimed to help spread
the weight borne by the tyre.
A large air chamber also helps
turn weight into traction while
minimising soil damage.
A stabilised tread and reinforced
radial casing allow the tyre to carry
heavy loads at low pressures, with
22 Crop Production Magazine –– September 2011
associated ride benefits. Michelin claims
the tyre’s broad flat crown with long deep
lugs helps produce a low slip rate and
minimal rolling resistance, benefiting
traction and saving time and fuel.
The OptiTrac DT830, from Goodyear,
is available in sizes up to 900/50 R42,
and has been specially
designed to keep the
width of tractors to
which it is fitted
within 3m.
Emphasis is on
soil preservation,
with the firm’s
Optitrac R+ tyre
being more suited
to particularly
high torque, high
load applications.
for topwork from their nominal 35psi
(2.4 bar) to 22psi (1.6 bar). This was
based on a calculation of the weight
we were operating at, the horsepower
available, the weight of the outfit and
the area of tyre on the ground.”
The result, says David Corbett, is an
overall footprint that’s 8% greater than
that of the smaller tractor. He believes
the machine is easily the match of an
equivalent crawler for traction when
doing this type of work. For the limited
amount of deeper cultivations carried out
by the farm, the pressures can be easily
and quickly increased again.
“Although radials offered a bigger
footprint, we were initially worried about
wind-up and bounce. This can be an
issue with getting power to the ground
with radial tyres on a high-hp tractor,
because of the nature of their design.
But it’s not an issue when properly
ballasted with nose weights, so a 60:40
balance turns into a 50:50 split when
at work.”
One of the other advantages of the
tractor over its tracked equivalent is
that it’s 4t lighter, points out Chris Corbett.
“Tracked units and their associated
components add a tonne to each corner
of the tractor, yet we have a lighter
machine that’s still capable of heavier
draft work when needed. Given the
performance of the tyres, I’d be quite
happy to run a 500hp machine on wheels.
“With the relatively minor price
difference, our only mistake with
both of these tractors was to not buy
a larger model.”
Around 120-160ha of the farm’s total
is ploughed rotationally for blackgrass
and brome control. An 11f Kverneland
plough is pulled behind one of the 2
artics, while a 6f plough follows a smaller
tractor for headland work. On its TM900
tyres, the larger tractor can be operated
at higher pressures for this and for any
necessary subsoiling work, with the
pressures being lowered for other
cultivation work.
For this, the farm runs a pair of 9.5m
pig-tail cultivators and 2 tillage trains.
One is based on a Watkins Tri-Till and a
Gregoire Besson disc/press combination,
and the other features subsoiler tines,
Väderstad discs and a gang of rolls.
“We prefer not to do primary cultivations
with discs, as we find tines mix the soil
better, don’t smear, and can work at
higher speeds. At 15km/h, we can cover
120ha/day –– allowing the result to green
up and be sprayed, followed by a repeat
operation, and even a third if required.”
Each cultivation pass costs just £15/ha,
he estimates. “We then drill with an 8m
Horsch CO, working at 15-20km/h and
covering up to 100ha/day.”
Operating in this way, the tractors’ tyres
are expected to last for at least 3000hrs,
and with regular, careful servicing, few
other major costs are anticipated.
Width reduction
“With the same amount of work under
its belt, a crawler would probably need
new belts and idlers, plus other running
gear maintenance. Put simply, we think
a wheeled tractor is likely to be far more
reliable and cheaper to maintain.”
Although there’s little long-distance
travelling –– five miles at most –– ease
of travelling, when compared with a
dual-wheeled tractor or crawler, is
nonetheless welcome. Both of the
machines fall just within 3m for on-road
travel, with the 900-tyred tractor on
wheels that reduce its width to less
than the other machine.
“We still run 3 of our Magnums,
as they’re probably only worth £20,000
apiece, and they’re simple and reliable
to operate. In the same way, we’ve
retained a number of our older smaller
tractors for lighter work, and the Steigers
are the newest machines we run.
“But they’re likely to stay until they’re
worn out, which could be as much as
20 years. There’s very little to go wrong
or replace on them, and what we paid
for the 2 would probably buy just one
Corbett Farms Steiger tyre comparison
Tyre pressure is reduced for drilling
and topwork.
Quadtrac today –– and we’d also be
forgoing a lot of flexibility.”
Both machines are fitted with Trimble
autosteer systems using the EGNOS
correction signal, with markers rather
than GPS still used for drilling.
“It’s another factor that makes newer
articulated tractors much easier to
operate,” believes Chris Corbett.
“Because of the way they steer, I wouldn’t
want to operate auto-steering on a
twin-track crawler. But on a wheeled
tractor it makes sense. We have a very
good drill operator, but in time we may
upgrade to a more accurate system that
we could use for drilling.” ■
Farm facts
Corbett Farms
●
Soils: Clay loam, primarily stone-free
●
Staff: David and Chris Corbett, plus
four staff (also work on recycling and
building businesses)
●
Cropping: Mainly winter wheat
(Glasgow, Robigus, JB Diego, Oakley,
Duxford, Deben)
●
Livestock: None
●
Tractors: Case IH Steiger 435 and
STX375, Magnum 7250 x2 and 7220,
MX135 x3, 5150 x3, CVX150
●
Combines: 9m New Holland CX880 x2
●
Handlers: JCB Loadall 530-70
●
Sprayer: 24m Househam 4000-litre
self-propelled
Trelleborg TM900
Trelleborg TWIN 414
Radial
Cross-ply
900/60 R38
850/60 R38
●
Spreader: 24m Bredal K85
Section width
905mm
850mm
●
Diameter
2040mm
1980mm
Rolling circumference
6180mm
5880mm
Cultivation equipment: 2x 30ft pig
tail cultivators, 2x tillage trains.
Kverneland 6f and 11f ploughs
2.4 bar (34psi)
2.4 bar (34psi)
●
Drill: 8m Horsch CO
Construction
Size
Nominal pressure
Crop Production Magazine –– September 2011
23
Disease control
Be on guard for phoma
and light leaf spot
The importance of oilseed rape as a national crop
means a robust disease control strategy is vital.
CPM quizzes the UK’s top expert Dr Peter Gladders
on phoma and light leaf spot.
Phoma appears as greenish grey or white
spots with black pycnidia.
By Tom Allen-Stevens
‘It’s fair to say that growers have
had a couple of lucky escapes
in recent years’
homa is the number one disease
for oilseed rape in England and
affects most crops, especially those
in the south. Cooler conditions in the
north of England and Scotland make it
less of a threat.
P
Why is phoma a worry?
Recent years have been reasonably high
risk for the disease, so control has been
justified. There’s every reason to believe
2011/12 will be an equally high-risk season.
Current crop returns, and OSR’s value
as a break crop, mean the area drilled
has ballooned over the past decade.
Increasingly the crop is grown in a tighter
rotation, with a two, or even just one-year
gap in between crops. This increases the
incidence of the disease and the amount of
inoculum that naturally exists within crops.
Yield losses from infection in susceptible
varieties would typically be around 0.7t/ha,
and the disease is estimated to cost UK
growers around £40M/year. Phoma can be
managed and minimised very efficiently
through the use of fungicides. But spray
timing and having a knowledge of how the
disease develops are crucial to get the
best from any strategy you implement.
What about light leaf spot?
The assertion that light leaf spot (LLS)
only affects northern crops is a myth.
It’s increasingly being found further
south. Last season most crops in the
south-east of England had symptoms
of LLS infection.
Although you could argue that LLS
is actually a more significant disease,
phoma’s severity in the south eclipses
LLS in terms of priority. But if LLS goes
unchecked, yield losses of as much as
1t/ha could be expected –– even 1.5t/ha
in extreme cases.
It’s fair to say that growers have had
24 Crop Production Magazine –– September 2011
a couple of lucky escapes from LLS
in recent years, when high levels of
infection in the autumn failed to take
hold too seriously in the spring. But
that may not be the case in 2012.
How do the diseases affect crops?
Phoma (Leptosphaeria maculans) starts its
lifecycle in oilseed rape stubbles. Airborne
ascospores are released from fruiting
bodies left in crop debris, and these
travel to infect newly emerging crops.
High humidity or leaf wetness are
needed for infection to occur. As a guide,
you need around 20 days on which it’s
rained after 1 Aug before there’s a high
risk that new crops will be infected.
The infection manifests itself as light
coloured spots on the leaf. These will
often contain tiny black dots or pycnidia
–– asexual fruiting bodies that release
spores to cause secondary infections.
Over the winter months, the infection
grows down through the leaf, until it
reaches the leaf base at the stem. Then,
Disease control
How can you identify and monitor
the diseases?
You can tell the level of infection you’ve
had previously from canker by inspecting
the stubble –– infected roots are black.
Phoma infection on the new crop
appears as greenish grey or white spots,
about 1-2cm in diameter. The black
pycnidia are just visible to the naked
eye, with the underside of the leaves
remaining green.
There’s also a closely related species to
phoma known as phoma B (Leptosphaeria
biglobosa). This shows as small, dark leaf
spots around 2-10mm in diameter. This
isn’t usually damaging to yield.
The threshold to treat for phoma is
when around 10% of plants are infected
in the autumn. LLS shows as less distinct,
yellowy-green spots and the threshold for
treatment is 25% of plants affected at
stem extension.
The difficulty for both diseases is that
it can be hard and time-consuming to
monitor crops. Phoma can develop very
quickly within crops –– last year infection
arrived in late Sept and symptoms were
visible by the second week of Oct. But
many crops went from 0-100% infected
in just a week.
Light leaf spot shows as a less distinct,
yellowy green spot.
Rothamsted Research coordinates a
forecasting service (see panel on p26).
Crop Monitor also measures levels of
pests and diseases in UK oilseed rape
crops (www.cropmonitor.co.uk).
Keep your ear to the ground. For
phoma, it’s very important to know
when crops have reached the autumn
treatment threshold, and when to spray
as this will affect the fungicide and dose
rate you choose.
How can you avoid the diseases
spreading?
Choosing resistant varieties is the best
way to minimise the impact of phoma
▲
as the spring temperatures warm up,
these infections cause lesions or cankers
–– a girdling of the stem that cuts off
the water supply so the plant dies
prematurely, prior to harvest.
The earlier the spotting occurs, the
earlier the canker occurs. What’s more,
the smaller the leaf, the quicker the
infection will travel through the petioles
to the stem.
Like phoma, LLS (Pyrenopeziza
brassicae) originates from spores
released from crop debris which infect
new plants. Again, asexual spores
(conidiospores) are produced which
are spread by rainsplash close to the
initial primary infection, or foci. This
tends to make an infection more patchy
within a field.
LLS symptoms aren’t frequently seen
in the field until Jan, though infection
occurs in the autumn. As the crop grows
in the spring and old leaves senesce, the
pathogen enters another sexual stage,
producing apothecia that release a further
flush of wind-dispersed spores, infecting
new leaves and flowers. Spores can also
be transferred by rainsplash.
Infection causes necrosis of leaves
and flowers which directly affects the
plant’s productivity.
Disease control
lands late on a large leaf is less likely
to reach the stem than one that lands
early on a small leaf. Getting good
establishment early on will therefore
reduce the level of canker, even where
there’s been a high infection of phoma.
How do you control them?
There’s every reason to believe 2011/12
will be a high-risk season, says ADAS’
Peter Gladders
▲
and LLS. However, most varieties are
susceptible and you’d need a rating of 7
or above to ensure adequate resistance.
You can reduce the spread of spores
by burying trash soon after harvest. For
phoma, your crop will still be exposed to
infection via wind-borne spores from
neighbouring farms but LLS tends not
to travel so far and will hang around on
individual farms. If you have problems
with the disease in one year, it’s likely
these will persist for the future.
Good crop growth can limit the impact
phoma will have –– an infection that
Once you’ve reached the 10% treatment
threshold for phoma, you have about
a week to spray your crop to check
the development of the disease.
Prothioconazole, difenoconazole and
flusilazole all have good activity against
the disease. But while actives such as
prochloraz and metconazole may be
effective growth regulators, they are
weaker on phoma.
A good strategy is to aim to spray two
half rates in the autumn. They will each
give you around 3-4 weeks protection,
so you should start looking for signs of
reinfection once this period is over.
Typically this could be 6-8 weeks after
your initial treatment.
Once you get into Nov, it may be worth
applying a holding spray if you haven’t
seen disease symptoms, bearing in mind
that you may not get back into the crop
until spring. By mid-Dec, the disease
should’ve ceased spreading through
the crop.
Ideally, you need a dry leaf and a
medium/fine spray to help the active
stick to plant material. This may not
always be easy to achieve in autumn
with heavy dews and damper conditions.
Take care if tank-mixing with herbicides
–– soil-acting residuals may require a
different quality spray.
Phoma sprays will keep LLS in check
in the autumn, but a specific autumn
Quick check on autumn oilseed
rape diseases
●
Phoma a priority in the south but all
growers should check for light leaf
spot (LLS) as well
●
Phoma causes stem canker which
can hit the yield hard
●
Onset of phoma triggered by 20 days
of rain from 1 Aug
●
Look for light spots on the leaf –– the
threshold to treat for phoma is 10%
leaves infected, while 25% is the
threshold for LLS at early stem extension
●
Use a monitoring service and keep
your ear to the ground to help decide
when it’s best to spray
●
Make sure you use a product with
activity on phoma, with a second
treatment 6-8 weeks later to clear
up secondary infection
Phoma and light leaf spot forecasting
Rothamsted’s Dr Jonathan West expects
phoma levels to be similar to last autumn.
Rothamsted Research provides information
on when the threshold for phoma treatment
is likely to be reached (i.e. 10% of plants
showing symptoms). An interactive map
is used to display data, based on a
scientific model of how the disease is
likely to develop.
The disease is expected slightly earlier
than average, at low levels and sporadic with
some fields missing it until much later, says
Rothamsted’s Dr Jonathan West.
“The summer’s been quite wet, which
promotes a very early maturation of the
fruiting bodies in the autumn, sometimes
as early as mid-late Sept. But this is now on
the back of two very cold winters. These
actually delay development of the cankers
and the resulting less severe cankers tend
to have later development and release of
the airborne ascospores. So we believe the
phoma leaf spot will not be unusually early.”
This and the use of more resistant
varieties mean inoculum levels will be
sporadic. “So we expect it could be similar
to last autumn, with fairly early phoma leaf
spot in some locations but some individual
fields escaping infections.”
Rothamsted’s preliminary light leaf
spot forecast is usually issued in Sept or
Oct each year. This uses the previous
season’s pod incidence data and weather
data to produce regional risk forecasts.
The forecast is then updated again in
spring to the final forecast.
26 Crop Production Magazine –– September 2011
“The two cold winters recently have
promoted the disease in parts of the east
and south of England,” reports Jon West.
“It was quite severe in parts of Lincs and
Cambs this spring.”
He advises spraying against LLS in
mid-late autumn and again in late winter.
“For phoma, if there’s a fairly early onset,
two autumn sprays are often best with
no need to spray against new phoma
infections after early Dec.” New infections
so late in the year will not become severe
enough to reduce yield, he explains.
“The optimal regime depends on
location and since LLS has been
encouraged recently, while phoma
is less prevalent, a mid-autumn and
late-winter spray will be best for much
of the OSR-growing area of the country.”
Notifications come by e-mail, fax
or SMS text message. You can even
follow the forecast on Twitter
www.rothamsted.bbsrc.ac.uk/leafspot
or www.twitter.com/leafspot
Disease control
Fungicide focus for northern growers
A two-spray programme for light leaf
spot is essential, says JC Agronomy’s
Jim Callighan.
Oilseed rape crops in Northumberland
that yielded in the region of 5t/ha show
what can be achieved when good
agronomy combines with favourable
growing conditions, says Jim Callighan
of JC Agronomy.
While fungicide use is increasing year
on year, the average is still below four
sprays and too many growers are taking
a ‘wait-and-see’ approach, he says.
“More and more growers in the north
are now realising the benefits of using a
robust fungicide strategy for light leaf spot
(LLS)control. A two-spray programme is
now essential in most situations.”
Growers should aim to start with a
two-thirds rate of prothioconazole or
flusilazole, he advises. “Alternatively, if
some growth-regulator activity is needed,
switch to Prosaro (prothioconazole+
tebuconazole).
“Bear in mind that the dose rate
is important, as anything less than a
two-thirds rate won’t give sufficient
control and see the crop through winter.”
He also stresses the importance of the
spray timing. “It’s important to act at the
first signs of the disease being present,
which may be as early as mid-Oct. Delay
too long and it could spell trouble.”
Jim Callighan suggests that phoma
could become an increasing threat for
northern growers. “LLS is still the key
threat, but growers must be more vigilant
for both diseases.”
Phoma causes stem canker that cuts off
water supply, killing the plant.
application may be necessary where
phoma control isn’t required –– in more
northerly crops, for example. It’s also
important to monitor the disease in
spring and treat as necessary.
Consult your agronomist for the most
suitable rate, product and timing, and
always ensure label recommendations
are followed. ■
More reliable than the British weather.
Whatever the weather, Draza forte is the name you can trust.
Unpredictable weather shouldn’t mean unpredictable pest control.
And with Draza forte, it doesn’t.
Draza forte’s pellets are methiocarb-based and contain a high quality
binder. So they won’t dissolve in the rain, but stay where you want
them – in your field protecting your crop, even when it’s wet and cold.
What’s more, because the pellets are small and highly concentrated,
there’s less waste and less time spent filling your spinner. A winner
all round.
www.bayercropscience.co.uk
Draza® is a registered trademark of Bayer. Draza forte contains methiocarb. Use plant protection products safely. Always read the label and production information before use. For more product
information including warning phrases and symbols, refer to www.bayercropscience.co.uk. Bayer Assist: 0845 6092266. Alternatively call us on 01223 226644. © Bayer CropScience Limited 2011.
A significant step forward?
The Claas Lexion 770 has the same power output,
threshing system and grain-tank size as its 600
predecessor. So where does its claimed extra output
come from? CPM speaks to two early users.
By Martin Rickatson
‘It completed our harvest in
30 fewer combining hours
than with our old 600.’
P
28 Crop Production Magazine –– September 2011
Cropping spread
The 600 was rated capable of cutting
as much as 1600ha in a season. But
with the spread of cropping and the
limited harvest days available on the
Boyd land, much of which sits at the
base of the North Downs, the additional
capacity was an added insurance against
the weather.
The 600 was equipped with the
same 9m header. But more power, extra
grain-tank capacity, APS (Accelerated
Pre-Separation) concaves, a bigger
cleaning area, and the RotoPlus secondary
separation system all ensured it was a
significant step up from the 580.
“It gave us quite a bit of extra capacity
over the 580, and meant we could take
on more contract land, to the point
where we were putting 1200ha through
it,” explains Neil Harper. “It coped
well with what we asked it to do, and
the reliability was excellent, despite
the number of differences between
it and the 580.”
▲
utting 1280ha of cropping through
one combine is a fairly tall order,
particularly when climate, cropping
and labour constrain the harvest period
to around 25 days. But Kent-based
John Boyd Farms achieved its aim of
averaging around 48ha/day during the
first season running a Claas Lexion 770
last summer. It was on course to do the
same again this year when CPM paid
a visit.
The combine, one of a small number
of pre-production units on farm last
season before its official launch,
replaced a Lexion 600. While that
machine also harvested the total farm
area on its own, the business was keen
to factor in some extra ‘insurance’ into
its available combining capacity, as well
as catering for the possibility of adding
further contract-farmed land to its books.
But when the combine was first offered
to the business to test, farm manager
Neil Harper, who runs the day-to-day
operations alongside Mark Boyd, was
initially unconvinced that it offered
enough of a step forward over the 600.
“While we don’t tend to take on land
too far away from our base at Lenham,
between Maidstone and Ashford, we do
have a wide spread of cropping,” he
explains. This harvest it included 120ha
of oats, 240ha oilseed rape and 140ha
of winter beans, in addition to 780ha of
milling and feed wheat, split between
first, second and some continuous.
With dew restricting combining days
to 12 hours, from 10am to 10pm, or
occasionally midnight, managing with
one machine was always going to be
a challenge.
“Six years ago we were running a pair
of combines –– a Dominator 218 and a
Lexion 460. But when Claas launched
the Lexion 580, we felt that it would be
possible to run the one machine for our
whole acreage, given the claims made
for its potential output.”
The new machine was the farm’s
first with a 9m header. Over the next
three seasons it proved capable
of coping with a workload that was
steadily increasing as contract-farming
commitments expanded. Then, when it
came up for replacement, it was traded
in for one of the recently-introduced
Lexion 600s.
▲
The farm’s combines are run on a
service contract for three seasons.
“So when the 600 came up for renewal,
we were keen to have another, possibly
with the 10.5m header that had since
become available, to better match the
combine’s capacity.”
When they enquired about a
replacement machine, Claas asked if
the business would be prepared to take
on a pre-production version of its Lexion
600 replacement, the 770, that now
tops the new Lexion range launched
last summer.
“We were unsure initially, as the
600 had been very reliable. Claas had
The CEMOS system asks what the driver’s
operating priority is, then suggests ways to
improve it.
suggested that, rather than having more
power and a bigger grain tank, the 770
would use other features to offer greater
output than the 600,” says Neil Harper.
The machine was supplied with a
12m cutterbar with dual-drive knife and
centre-split auger. The 770’s Mercedes
engine produces the same output as the
600, albeit with the maximum 586hp
now achieved 100rpm further down the
rev range, at 1800rpm. The combine’s
internals include the same APS system
and twin RotoPlus separation rotors as
its predecessor.
But other major components have been
upgraded significantly. Among them is a
Prototype copes with demands of short days
Rick Buckle –– needed extra output.
Sea mists are a limitation for East Yorks
grower, Rick Buckle, who farms with his
brother Rob and father Geoff around Sunk
Island, near Holderness. They too ran
a pre-production Lexion 770 last season
over the farm’s alluvial soils that are
capable of producing 12t/ha wheats with
5t/ha of straw.
But cutting 1280ha of crop is asking a
lot of one combine, he notes, particularly
because of the land’s proximity to the sea,
and consequent mists, which mean
combining days are necessarily short.
“We have some land that’s just 200m
from the sea, where moisture contents can
be 4% higher on the same day than on
inland fields,” explains Rick Buckle. “That
limits us in the length of our combining
days, and we can usually only cut from
10am to 8pm. So anything we can do to
increase throughput is welcome.”
They’d been running a Lexion 580TT,
but recently took on a further 250ha of
land. “We needed a bit of extra output,
and when we spoke with our Claas dealer
ahead of last season, they asked if we
would try the pre-production 770.”
The machine was delivered with a
10.5m header, rather than a 12m. Rick
Buckle opted for the smaller unit given
his farm’s high grain and straw yields
and damper conditions.
“But the machine proved to have plenty
of horsepower to cope, and in wheat,
we’ve typically been running at only 50%
available power, even though average
30 Crop Production Magazine –– September 2011
output was around 60t/hr. That’s a 27%
increase on the 580, which would have been
running at nearer 100%. And overall, our fuel
use was 1 l/ha lower with the 770.”
He concedes that initially he didn’t think
the CEMOS system would play a big role
in boosting output over his old 580.
“I do tend to make the effort to fine-tune
settings myself, because I want the
combine running as near full capacity as
possible. But CEMOS is a lot more helpful
than I thought it would be, and it worked
well from the start. Sometimes it provides
ideas that I would’ve tried myself, but
at other times it offers ones I wouldn’t
have considered.
“I’ve since used it all the time. Combined
with the Laser Pilot automatic steering and
Cruise Pilot II automatic feedrate controller,
I can use CEMOS to push the combine for
throughput. Last year we easily averaged
60t/hr, and sometimes more. One day, we
managed to put 800t through the machine.”
For an on-line demo of how CEMOS works, go
to: http://app.claas.com/cebis2010/cebis.html
volume of crop entering the combine,
the engine load and grain losses to
speed or slow the machine, and to
maintain the required throughput to
maximise productivity.
In-field setting-up time is reduced
through a larger CEBIS (Claas Electronic
on Board Information System) screen,
with flashcard reader and greater
crop-setting storage capabilities.
A ‘hotkey’ function speeds access
to the machine’s primary settings
and functions.
More interest?
But it’s the CEMOS (Claas Electronic
Machine Optimisation System) that is
arguably of more interest in terms of
potential output-boosting in-cab features.
It operates through a second removable
CEBIS console –– CEBIS Mobile –– which
can control a variety of applications,
such as the GPS Pilot steering system,
and can be transferred to other
machines out of season.
“Some operators, particularly new
or inexperienced ones, tend to stick to
standard settings, and perhaps won’t
tweak them for different conditions until
they have more experience. Even then,
Boyd Farms manager Neil Harper is
pleased with data showing the 770 ran
at peak efficiency 74% of the time.
they’re likely to stick with those settings
rather than tailoring them to individual
situations,” explains Claas systems
specialist Edward Miller.
“CEMOS analyses all aspects of the
combine’s settings and performance,
quickly and on the move. Once the
machine has begun work in the crop,
it asks the operator which performance
▲
constant pressure, load-sensing hydraulic
system providing a 50% increase in
hydraulic reaction time. This makes
functions such as Auto-Contour and lateral
levelling twice as fast as before and so
allow for higher operating speeds.
Behind the increased hydraulic
response is a rise in working pressure
from 180 bar to 200 bar, and a 50%
increase in pump volume to 120 l/min.
To complete the hydraulic upgrade,
steering system pressure has been
boosted to 175 bar to make headland
manoeuvring smoother and faster.
The heavily-revised, third-generation
Terra Tracs, fitted as standard to the
770, incorporate hydro-pneumatic
suspension. This helps to cut cab
vibration and allows for faster, more
comfortable travel, increasing overall
performance. Along with the revised
hydrostatic transmission, the suspension
also allows for a 30km/hr top speed,
reducing between-field travel time.
As part of a linked set of revised
electronic aids which Claas terms EASY
(Efficient Agriculture Systems), the 770
is also fitted with its new Cruise Pilot II
automatic feedrate control system.
This can be activated to monitor the
Throwing material out to the
full 12m cutting width is no
problem for the 770’s Special
Cut II straw chopper.
▲
parameter is his priority ––
crop flow, throughput, losses,
grain quality, returns –– and
then makes suggestions as
to how it can be improved.
“The operator can then
ask for an explanation of the
suggestion, and choose to
select or reject it. If rejected,
other options will be given, but
if selected, the system will
make the change automatically
and then show the difference it
has made, with options provided
to assess the difference.”
Further options can then be
presented if required, and where
optimum performance has
been found for a certain set
of conditions, the settings
can be stored for future use.
Extra operator
When first instructed on its
use on his pre-production
770, CEMOS was described
to Neil Harper as “having
an extra operator with all of
Claas’ collective experience in
the cab with you,” he recalls.
“The idea was daunting
to start with, in terms of the
number of options it presented,
but in essence many of them
are things an experienced
operator would consider
anyway,” he suggests. “But
it’s a useful tool for getting
more out of the machine.”
He aims to run at 0.75%
losses, or at least under 1%.
“We don’t want to throw grain
out the back of the combine,
but we need to push on and
get our acreage cut within the
limited time we have. That
32 Crop Production Magazine –– September 2011
means we need to average
55-65t/hr in wheat, which
translates to a spot rate of
around 85t/hr. Usually, I work
at achieving that output, then
check behind the machine
to assess losses, making
adjustments accordingly,”
he continues.
“We initially had some
problems keeping the sample
clean when pushing output,
but the TM6 frogmouth sieves
and linseed-type rotors
installed in the machine for
harvest 2011 –– the latter
having a bigger diameter
–– should help here.”
At first, the CEMOS system
suggested the returns were
higher than they actually were,
but this turned out to be
a software issue. Claas quickly
sorted it out, and since then
it has worked well, reports
Neil Harper.
“It’s a good tool for getting
more from the machine,
although experienced drivers
might find some of the
suggestions are those they
would normally try anyway.
The help button, which gives
a more detailed explanation
of why the change is being
suggested, works well, as does
the photo clip to illustrate the
setting change.”
In all, Neil Harper is
satisfied that the 770 is a
significant step up from
the 600.
“It completed our harvest
in 30 fewer combining hours
than with our old 600. Where
we were averaging 40ha/day
with that machine, the 770
was doing 48-60ha/day, and
New generation suspended
Terra Tracs improve both
in-field ride and on-road
speed, boosting the 770’s
capacity over the 600.
The Lexion 770’s 12,000 litre tank is the same size as the 600’s, but
more throughput means a trailer upgrade has been necessary.
76t/hr was my best average
in an eight-hour spell.
We subscribe to the
ClaasTelematics system,
and our data shows that
last season we were at peak
efficiency 74% of the time,
which I’m fairly pleased with.”
Electronic systems
Aside from its electronic
systems, other aspects of the
machine also helped maximise
output. “The 12m header took
surprisingly little time to adjust
to. The chopper happily blows
straw to the full width, although
turning and sharpening the
chopper blades is important
to avoid sapping power and
affecting output.
“I wasn’t able to make
much use of the Cruise Pilot II
feedrate system last year, as
it was being modified on the
pre-production machine. But
I’m aiming to have more of a
play with it this time. This is
also our first season with GPS
steering rather than the Laser
Pilot system, and both these
things should help output.”
And there are other ways
output is boosted. “The
30km/hr travel speed also
helps save time, particularly
as we don’t like to risk leaving
the machine in the field. So it
returns to the nearest yard
each night.”
For 2011, they’ve also
changed the 12t trailers for
two new 16t Marstons, plus a
further borrowed one. “We’ll
probably need these for a
quarter of our acreage that’s
further away from the store.
Unloading on the move, we
can put in 10t in one go, and
then top up. Despite having
the same-size grain tank,
the 770 has proved its extra
throughput capabilities, so
having the right amount of
trailer back-up is essential.” ■
Farm facts
John Boyd Farms
Lenham
Maidstone
●
Farm size: 1280ha
●
Cropping: 780ha winter
wheat (Gallant, Cordiale,
Robigus), 240ha
oilseed rape (SW21,
Expower, Castille),
140ha winter beans
(Wizard), 120ha oats
(Gerald)
●
Soils: Clay loam with flint,
some chalk
●
Labour: Mark Boyd and
Neil Harper plus one
full-time tractor driver and
one summer student
●
Tractors: AGCO
Challenger MT865B,
John Deere 8530, 7830,
7530, 7810, 3050
●
Combine: 12m Claas
Lexion 770
●
Sprayer: Bateman RB35
32m/4000l
●
Cultivation/drilling
equipment: 6.0m Simba
Solo, 6.6m Simba
Cultipress, 10.5m
Vaderstad Carrier,
6.0m Horsch Sprinter
●
Trailers: 16t Marston x2
plus another borrowed from
contract farm
Making tracks to
controlled traffic system
A pre-production John Deere S690i combine,
equipped with the firm’s new tracks, is a key
component in a Lincs farm’s move into
controlled traffic farming.
The John Deere S690i delivers a good chop
and spread –– an important start for the
direct drill.
By Mick Roberts
‘All I had to do was save the
information from the office
computer and transfer it to the
GreenStar terminal on the combine.’
T
34 Crop Production Magazine –– September 2011
wanted to start using CTF to reduce
wheelings and compaction, I’d never
have considered changing to another
make unless it also came on tracks.”
Greenstar fleet
But with a John Deere tractor fleet and
self-propelled sprayer, all equipped with
the firm’s GreenStar 2600 terminals and
StarFire GPS receivers, he was persuaded
to try the company’s pre-production
S690i combine. Importantly, this was
one of the first to come equipped with
factory-fitted tracks. He was not only
impressed with how the single-rotor
harvester performed, but felt it would
be a better fit for the CTF system the
farm was putting together.
“While we could’ve fitted another
combine with the John Deere equipment
we were using in the other machines,
▲
he electronic monitoring and
control equipment were not the
main reasons why farm manager
Matthew Neesham invested in one of the
first John Deere S690i combines to be
sold in the UK. But compatibility with
his existing system certainly played
a big role in his decision, he says.
This is because it arrived at a time
when Neesham Farms, based at Manor
Farm, Lissington, was making a move to
controlled traffic farming (CTF) across its
1200ha of cropping, which comprises
700ha of its own land and a further
500ha of contract farming.
“We change the combine every 3
years and last season this also coincided
with the switch to the CTF system,” says
Matthew Neesham. “I’d been pleased
with the performance of the previous
Claas Lexion 570+ with Terra Tracs and,
Another consideration was the need to
upgrade the GPS signal accuracy to RTK
(Real-Time Kinetic) precision to keep the
CTF equipment on track. As this was
being provided by two John Deere base
stations, it again made sense to stick
with the same supplier for the harvester.
Header fit
The grain trailer tractor, also equipped
with AutoTrac steering, runs on an
adjacent tramline, helping to minimise
the wheelings.
▲
it was simpler to stick to the same
manufacturer for all. This made it much
easier to use all the CTF data we’d
already saved in GreenStar using the
Gatekeeper (software) format. Rather
than having to switch control boxes
between different machines, all I had
to do was save the information from
the office computer and transfer it, via
a compact flash card, to the GreenStar
terminals on all the machines, including
the combine,” he explains.
In common with other CTF systems, the
combine header sets the bout width for
the production regime at Neesham
Farms. The S690i’s Zürn PremiumFlow,
at 9m wide, is a good fit with the existing
JD 5430i sprayer with 36m wide booms.
This, explains Matthew Neesham, means
that on every fourth run the combine
travels on a tramline with three bouts in
between. “This provides a significant
reduction in wheelings and, at an actual
cutting width of 9.14m, the header
provides a little leeway each side.”
“Moreover the AutoTrac steering keeps
the combine on the set wheelways and
the same system is also fitted to the
grain cart tractors. The combine auger
is long enough to allow the tractors to
self-steer down the adjacent tramline,
which also helps to minimise the
wheelings across the field.”
Although the combine’s track width is set
at a fixed 2.85m, one of the most difficult
elements in setting up the CTF system was
to choose and then implement a common
wheel centre width for all machines.
Ultimately Matthew Neesham settled on
2.5m centre-to-centre distance, but at this
setting the combine’s tracks overlap the tyre
wheelways by about 35cm each side.
While not a problem for the sprayer,
which has hydraulically adjustable axles,
the farm’s 180hp John Deere 7530 tractor,
along with another owned by a contract
partner, have been fitted with special
wheel extensions. The farm’s other tractor
a JD 8530 is already equipped with
Soucy tracks, which are set at 2.37m.
With its factory-fitted tracks and 9m wide
PremiumFlow header, the S690i fits neatly
into Neesham Farms’ controlled traffic
farming system.
36 Crop Production Magazine –– September 2011
“The machines which aren’t running
dead centre on the CFT wheelways are
all tracked so that means compaction is
less of an issue. But we now only travel
on 17.5% of the field, excluding the
permanent tramlines –– or 23.3%
if they’re included,” he adds.
Grain-cart dilemma
Grain carting is the only part of the
system which he feels still needs
attention. The existing trailer wheels,
set at 2m centres, don’t fit the system
and continue to be a prime source of
compaction. The answer, says Matthew
Neesham, will either be to extend their
axles outwards, or to invest in a chaser bin
to reduce the pressure on the soil.
With the base stations installed in
February last year, Matthew Neesham
used the highly accurate signal to map
all the fields and set up the A-B lines for
all the permanent wheelways. These
were then transferred to the terminals on
all the machines so each operation now
follows exactly the same paths.
All the crops being harvested this
year were established using the CTF
system with cropping including winter
wheat, oilseed rape, winter and spring
linseed, spring barley as well as sugar
beet on the contract farm.
Now in its second harvest at Neesham
Farms, the combine not only fits well with
the CTF system, but is also performing
well in its own right. “As an example of
its output, I managed to cut 78ha of
barley in 14hrs –– chopping the straw
as well. The crop yielded 6.25t/ha and
that included moving between farms,
which took about an hour.” The average
output is about 5ha/hr across all the
crops and fuel consumption ranges
between 15-25 l/ha.
“I’ve noticed the combination of the
header and rotor have made a big impact
when cutting linseed. The crop has a bad
reputation when it comes to harvesting
–– it wrapped around the rotors on our
previous combine. But feeding with the
Zürn powered header makes it a lot easier
–– I find the single cylinder, large rotor
copes much better with threshing the
crop without any wrapping problems.”
The HarvestSmart system improves
capacity further in all crops, he continues.
“It adjusts the forward speed automatically
depending on the load on the threshing
system.” Although it took a bit of time
to set up, Matthew Neesham feels it’s
Farm manager, Matthew Neesham, says
implementing a controlled traffic system
means the machines now travel on just
17.5% of the field.
now a good addition that increases the
machine’s throughput.
To improve the straw chopping
and spreading, his JD S690i is fitted
with a new MaxiSpreader. Residue
management is an important element in
the farm’s direct-drilling system and the
independent, hydraulically driven discs
produce a good chop and an even spread.
These can be adjusted individually to cope
with the wind direction and speed to help
maintain a good distribution across the
whole swath width. ■
Crop Production Magazine –– September 2011
37
Harvester headway
It’s not just the size of the New Holland CR9090
that brings an output boost, it’s the technology the
combine has on board, says one Warwicks grower.
By Simon Henley
is the largest of the twin-rotor Elevation
combines produced by CNH. Introduced
in 2009, it’s powered by an Iveco Cursor
engine producing 591hp (max).
Equipped with a 10.7m single span,
Varifeed header, it’s claimed to be
the highest output combine available
anywhere in the world today.
High capacity
‘Effective utilisation of our
combines is crucial.’
I
38 Crop Production Magazine –– September 2011
Coming with a £300,000 price tag to
match –– plus another £50,000 for the
Varifeed header –– it’s a harvester suitable
for only a handful of UK growers. It’s
aimed squarely at users that need high
capacity when the crops are fit and,
very importantly, businesses with a grain
store set-up capable of handling this level
of output.
“Primarily, we grow winter feed
wheat, oilseed rape and spring malting
barley,” says Ken Grimsdell. “We tend
to favour Group 4 feed wheat varieties,
such as Oakley, Duxford and Grafton
–– the latter being an early finisher.
The oilseed rape area we plant is split
into one-third conventional varieties
and two-thirds hybrids.”
Driving a combine of this size isn’t
for the light hearted nor inexperienced.
Extracting the best from it in terms of
performance isn’t as difficult as it may
seem, as R & T Ensor’s combine operator,
Tim Burn explains.
“In standing wheat, the CR9090
can cut 50ha/day in crops consistently
yielding 10-12t/ha,” he says. “Getting
▲
n any harvesting operation, timeliness
plays a key role. When you’re cutting
1560ha of combinable crops on farms
that are more than 18 miles apart at the
furthest point, the speed and efficiency
of your combines become critical.
Handling the harvesting duties for
Warwicks-based R & T Ensor (Farmers)
are two combines, including New
Holland’s largest model ever, the
CR9090 Elevation. This is fitted with
a 10.7m Varifeed header which works
alongside the farm’s 2006 NH CR980,
fitted with a 9m Biso header.
There’s a high horsepower theme that
runs through much of the kit used by
the Ensor family since the 1970s. This
includes the tractors that perform
all cultivation duties and the cultivation
trains developed for min-till seedbed
preparation.
“Timeliness is a very important factor
in our operation,” says farm manager
Ken Grimsdell. “Our land is spread over
quite a distance, so effective utilisation
of our equipment –– particularly the
combines –– is crucial.”
They initially purchased the CR9090
to replace a CR980, one of two they
were running at the time. “We intended
to sell the second CR980 eventually
and run just the one CR9090. But, during
its first year with us, the CR9090 was
beset with a number of unfortunate
teething problems and under-performed
throughout the season. The CR980
proved invaluable as a back-up combine,
so we decided to keep it for another year,
in case New Holland couldn’t get the
CR9090 up to par.”
The following year (2010) proved a
particularly challenging harvest with
limited windows of opportunity to cut
the crop. “The CR9090 performed
much better, but the CR980 again
proved useful, providing the additional
cutting capacity of two combines when
we needed it most.”
The Ensor’s New Holland CR9090
Farm manager, Ken Grimsdell says the
CR9090 alone would be more than
sufficient, if the land was in one block
and he had a single, central grain store.
▲
the best from the combine simply
involves setting it up carefully to work in
specific crops, then driving it according
to the loss monitor readings –– usually
set at 1% or just below –– which are
displayed on the in-cab ‘run’ screen.”
Satellite technology plays an important
role at R & T Ensor’s farm. An Omnistar
GPS system guides the CR9090, which
is also equipped with New Holland’s
Intellisteer auto guidance and Intellicruise
systems. The same system is also used
on the farm’s Bateman RB26 sprayer
and its New Holland T9060 primary
cultivation tractor. For Tim Burn, GPS is
a feature he now considers a necessity
on any large, high-output machine.
“Once the headlands have been cut,
auto-steer enables me to concentrate
on what’s going on with the combine’s
performance without worrying about
where it’s going,” says Tim Burns.
“A 10.7m header takes a lot of watching
when you’re working at 6kmh. Knowing
the combine will safely follow a preprogrammed track, while maintaining
a full cut at the maximum achievable
harvest rate, is very important.”
The CR9090’s huge Varifeed header
has a cutterbar that’s adjustable fore and
aft from the driver’s seat, to improve flow
to the feed auger. With the cutterbar
extended, tall crops like rape have time
to fall heads first onto the cutting table,
which improves feeding and helps
reduce pre-threshing losses.
Protection from stones and in-field
debris is another vital aspect to maintain
output on any high capacity combine.
On New Holland’s CR 9000 Elevation
Series, this is provided by an automatic
trap door that stops any rocks passing
into the feed elevator. The ‘tinkling’
sound of a stone or hard object as it
passes through the header is detected
by an acoustic sensor, which triggers the
trap door to open immediately, ejecting
the offending object.
Impressive sight?
From the driver’s seat, the sheer volume
of crop being delivered into the feed
elevator by the header intake auger is
an impressive sight. Pushing on hard in
standing wheat, the 12,500-litre grain
tank fills about every 10mins, with
well over a tonne of clean grain being
harvested every minute. That means an
output of 570-600t is readily attainable
in a 12hr day –– depending on crop
conditions and yield.
Keeping up with the combines are
six tractors and grain trailers, with the
CR980 unloading in the conventional
way directly into the trailers. But to avoid
unnecessary in-field travelling, and to limit
soil compaction and increase in-field grain
storage capacity, the company uses a 23t
capacity Hawe Chaser bin –– running on
low ground-pressure tyres –– to work with
the CR9090.
This is pulled by an articulated
Ford-Versatile 9680, equipped with an
in-cab terminal so the tractor operator
can monitor the grain dropped in the
hopper. Emptying takes place on the
The CR9090 fills its 12,500 litre capacity tank in about 10mins, so requires serious support
in the form of this 23t Hawe chaser bin, on low ground pressure tyres.
40 Crop Production Magazine –– September 2011
The Intellisteer system guides the CR9090,
while the Intellicruise speed control system
provides further operator support
move with the grain being transferred
to the waiting tractors and trailers on
the headlands.
“Unloading the combine on the move
is actually very easy using GPS,” says
Tim Burn. “The chaser bin driver simply
looks forward, maintaining a parallel
distance from the combine, matching
its speed. Because the combine won’t
deviate from its track, the chaser can
be filled to capacity without any risk
of spillage.”
The high capacity of the two combines
means they only ever work together in
oilseed rape. Once they’re into wheat,
they part company, with each machine
supplying one of the farm’s three
main grain stores separately, explains
Ken Grimsdell.
“During the rape harvest, we have
the intake capacity to handle both
harvesters’ outputs simultaneously
at one store location. In recent years,
we’ve modified our stores extensively
to improve their intake capacity. But
once we’re into wheat, none of them
can singularly handle the consistent
120-130t/hr produced by both combines
working together,” he says.
“If we had a ring-fence operation,
with all our land blocked together, and
operated one central grain store, I’ve no
doubt that the CR9090 would be more
than sufficient to handle our acreage on
it’s own –– and some may argue that
it still is.”
But recent harvests have proven the
value of using two combines of this size,
he believes. “It gives us the additional
capacity and flexibility not only to expand
our acreage, as we’ve done this year, but
also to clear the ground faster. That
means we can get the cultivation tractors
working more quickly –– and next year’s
crops drilled as soon as possible.” ■
Mucking up the value
of straw
Rising fertiliser prices, and straw worth more off
the field that on it, have put the value of manures,
composts and wastes in a whole new light.
By Tom Allen-Stevens
‘It’s becoming even more critical to
assess nutrient needs accurately
and to replace dwindling reserves’
uch has been said about what a
no-brainer it is to remove straw
this year. With prices over
£200/ha, and many contractors clearing
fields before you’ve had time to blink,
you’d be hard-pushed to argue growers
need straw back in their soils more than
other farmers need it for feed or bedding.
“It’s always difficult to equate the
value of lost fertiliser carted away on
the trailer, compared with the value
of baled straw,” says Dr Jerry McHoul
of K&S. “But with big-bale wheat and
barley straw prices of £45-70/t this
harvest, many growers opted not to
chop this year.”
In most cases, even with low straw
volumes, the revenue far exceeded
the cost of replacing the nutrients
with bagged fertiliser. But the latest
Professional Agricultural Analysis Group
(PAAG) figures suggest that around 30%
M
42 Crop Production Magazine –– September 2011
of arable soil samples analysed are
below the recommended index for
potash (K).
Dwindling reserves
“So it’s becoming even more critical
to assess nutrient needs accurately, and
to replace dwindling reserves. Those
who’ve taken a potash ‘holiday’ in recent
years, and who now have areas of fields
below index 2, will almost certainly
have seen the effects of this year’s
spring drought exacerbated because of
compromised water-use efficiency.”
The new RB209, published last year,
puts many of the figures growers need
to balance up their nutrients at their
fingertips. Around 83kg/ha potash is
removed in total by an 8t/ha wheat crop
with straw baled, along with 67kg/ha
phosphate.
“As a rule of thumb, baling removes
around double the amount of potash,
compared with where straw is chopped
and put back into the soil system,” notes
Jerry McHoul. “At the same time, growers
need to weigh up the costs of lost organic
matter from carting straw off the field.”
But straw incorporation does have its
downsides, he admits. “These include
the power and additional time needed to
Material
Applic. rate
(t or m3/ha)
Manure/residue nutrient content
Total applied
N
P
available to
current crop
K
N
P
K
Straw incorporated
4
0
5
38
0
5
38
Cattle FYM
40
240
128
320
24
76
288
Broiler litter
8
240
200
144
76
120
130
Cattle slurry
50
130
60
160
60
30
145
Biosolids (digested cake)
20
250
260
12
32
180
10
Green compost
30
239
99
171
60
59
154
AD digestate
60
240
38
165
144
23
149
Paper crumble (biol. treated)
50
179
39
192
60
13
64
is relatively expensive. There are other
sources that are equally as effective, and
which bring with them a host of other
benefits. But farmers must understand
what’s being applied.”
The table above shows the main
nutrients applied from a number of
different sources. “The RB209 figures
provide a guide only and these can
vary considerably. It’s important to
get manure samples analysed so you
apply the appropriate amounts. You
should also have a clear idea of your
own soil analyses.”
Growers must understand what they are
applying when spreading manures and
by-products, says ADAS’ Peter Dampney.
Whether using RB209 or a sample
analysis, nutrient content is expressed in
total amounts of what’s readily available
to the crop. The key consideration for
most growers is that no more than
250kg/ha of total manure N may be
▲
chop the straw on the combine, together
with issues of the trash at cultivation and
drilling –– with greater pest and disease
control often required.”
Overall, this arguably gives straw
more value off the field than on it. But
is bagged fertiliser the best way to
replenish the nutrients?
“The nutrient side is fairly straightforward,” suggests Peter Dampney of
ADAS, who helped compile RB209.
“To maintain soil fertility, you need to
replace what the crop takes from the
soil, and applying this as bagged fertiliser
The value of various manures, composts and residues compared
with straw removal
By-products, such as paper crumble, can
have a valuable nutrient content and
soil-conditioning benefits.
▲
applied in any 12-month period in an
NVZ (Nitrate Vulnerable Zone).
Slow release
“N value will depend on the type of
manure used and how and when it’s
applied to the crop. FYM contains a
relatively high proportion of slow-release
organic N which is broken-down naturally
and only released over several years.
Slurry contains more readily available N,
but bear in mind that a lot of N can be
leached - especially if it’s applied in
the autumn. Moreover where slurry is
surface-applied, rather than injected,
£300
15
£200
10
£100
5
£-
0
-£100
-5
-£200
-10
-£300
Straw
incorporated
Cattle FYM
(40/ha)
Broiler litter
(8t/ha)
Nutrient value to current crop
Cattle slurry
(50m3/ha)
Biosolids
Green compost
(digested cake)
(30t/ha)
(20t/ha)
Application or opportunity cost*
AD digestate
(60m3/ha)
-15
Paper crumble
(biol. treated)
(50t/ha)
SOM value (t/ha)
Nutrient content source: livetock manures – Defra RB209 (spring-applied to surface); biosolids –
Thames Water Biorecycling; green compost, AD digestate – Agrivert; Paper crumble – Greenworld.
AN cost £345/t; MOP £330/t; TSP £440/t; previous crop 8t/ha winter wheat, straw removed, nutrients
removed by crop 67.2kg kgP/ha, 83.2kgK/ha; current crop 8t/ha winter barley, N requirement
160kgN/ha.
* Based on manure spreading @£1.50/t and slurry spreading @£2.00/m3. Manure, slurry and litter
assumed to be provided free. Cost for straw incorporated reflects opportunity cost (no straw sold)
and extra fuel requirement.
NOTE: Nutrient content of manures, application costs and haulage vary considerably – check with
local provider for accurate assessment.
A spreadsheet is available for those wishing to plug in their own figures to assess
nutrient and SOM value. Go to www.cpm-magazine.co.uk
●
some of it volatilises and is lost to the
atmosphere as ammonia.”
The other essential element manures
provide is bulk. “If a farmer is looking to
build the water-holding capacity of his
soil, he should use a solid manure such
as FYM, which has 25% dry matter (DM),
rather than slurry, which is typically 95%
Waste not, want not
Nutrient lock-up is less of a problem with
biologically treated paper crumble, says
Greenworld’s Chris Legg.
The population of the Thames Valley region
flushes away more than 1B litres of effluent
every year. Following treatment and
processing by Thames Water Biorecycling,
that’s 1Mt of biosolids that need a home.
In West Sussex and East Hants, it’s
Chris Argyle’s job to find suitable places
to spread it.
“It can be difficult because we need to
minimise our haulage costs. We need a
minimum area of 25ha to spread on, and a
suitable site near a public road to deliver to.
We can’t cross roads when spreading, and
preferably, there should be no footpaths
within the spreading area. Moreover, there
are lots of fields we can’t spread on because
they already have a high P index.”
Biosolids are very rich in phosphate.
There are no phosphate vulnerable zones as
yet, he notes. “But as providers of clean
drinking water, it’s not in Thames Water’s
interest to risk applying biosolids where
the phosphate could be carried into water
courses. It’s rich in other nutrients too,
providing 80kg/ha of available sulphur
and 20kg/ha of available magnesium at
an application rate of 20t/ha.”
Digested sewage cake is now taking over
from lime-stabilised cake, which is being
phased out. The former is heat-treated to kill
any potential contaminates, such as E. coli.
“It doesn’t leave the treatment plant until it’s
guaranteed 99% pathogen-free.”
Part of the service is a full analysis of
what’s to be spread, and monitoring of the
soils afterwards. The cost to deliver and
spread varies, depending on location, but a
44 Crop Production Magazine –– September 2011
ball-park figure are around £25/ha for May to
October and £10/ha in winter and spring.
“We liaise closely with the farmer to make
sure we don’t make a mess of the soil and to
fit in with cultivation windows.” The material
must start to be incorporated within 24hrs.
Paper crumble is a very different waste.
150,000t per year is spread by Greenworld
from a base near Kings Lynn, Norfolk, and is
sold as a soil conditioner, rather than for its
nutrient value.
“The main benefit is 30t/ha of dry
matter from 50t/ha spread,” says contracts
manager, Chris Legg. “It improves the
moisture retention on light land and makes
heavy land more friable. You need to take
a long-term view –– it takes about 3-5
years to work in properly. It’s biologically
treated and includes the ink. This gives it a
nutrient value and a C:N ratio of 40-50:1.”
As well as N, P and K, it contains sulphur,
magnesium and copper, he says. “One
customer is having some to put right a
copper deficiency problem.” At 50t/ha,
haulage is the killer, although the cost is
from as little as 50p/t delivered and spread.
water. High DM manures and composts
have a valuable soil-conditioning effect
and build soil organic matter (SOM).”
SOM helps stabilise a soil, says Peter
Dampney. “It binds the aggregates and
helps provide air spaces between the soil
particles and clods. It also helps make
the soil more friable and crumbly, while a
soil with low organic matter will tend to
slump, compact and erode more easily
making it more difficult and energyintensive to work into a seedbed.
“The more a soil is worked, the more
SOM is lost as carbon dioxide, which
increases the farm’s carbon footprint.”
Long-term process
Check with your grain buyer before
spreading biosolids from sewage sludge.
need much to hit the 250kgN/ha limit.”
Paper crumble, a by-product from
paper mills and recycling, is often at the
other end of the scale (see panel).“It has
▲
Growers should aim for a SOM of around
3-5% –– with min-till helping to retain it,
he advises. “But don’t abuse the soil
then simply expect to be able to put it
right overnight with an application of
manure. Soil improvement is a long-term
process, and manure application will be
a good start.
“It then has to be integrated and
broken down by earthworms and other
natural processes,” notes Peter Dampney.
The right material for the job depends
on what the main priorities are and,
significantly, on what’s available. With
application rates of up to 50t/ha, haulage
and application costs can often be
prohibitive. Equally, if the farm lies near
a populated area or industrial site, there
could be a valuable manure source right
on the doorstep.
The chart opposite uses typical
values to illustrate the relative merits
of various manures, composts and
by-products. Application cost (or in the
case where straw is incorporated, the
‘cost’ of not selling the straw) should be
set against nutrient value to determine
a net financial return. The SOM value
indicates the additional soil-conditioning
benefit.
“The king of livestock manures is
broiler litter. In terms of its nutrient value,
it’s dynamite and has the benefit of some
dry matter too. However, its relatively low
application rate means it isn’t the best
for SOM. Also be careful not to overapply
and to ‘overcook’ the crop –– you don’t
Raking it in
Whether a farm is well placed to get
real value out of manures and wastes
depends on:
● Availability: what outlets are there
locally? It doesn’t have to be
a broiler unit. There are a growing
number of valuable waste streams
and by-products coming on to the
land, and the biggest cost for the
supplier is usually transport.
● Application cost: who’s going to
spread it? It’s usually a contractor
operation and requires specialist kit.
But prices charged vary considerably.
It also depends on what’s to be
applied –– paper crumble is spread at
about ten times the rate of broiler litter.
● Location: How suitable are the
fields? Proximity to main roads,
areas that can be covered in one
block, and current soil requirement
will make a difference. Then there’s
neighbours and footpaths –– some
of these materials really smell…
Crop Production Magazine –– September 2011
45
Digestate from AD plants has a high
nutrient content but low dry matter.
▲
a high carbon-to-nitrogen ratio and
can actually lock up nitrogen in the
soil or in applied fertiliser, unless it’s
biologically treated. But it’s very bulky,
and so is good for building soil structure.”
The nutritional content of paper
crumble varies, depending on source and
process –– the example used in the chart
is for material that has been biologically
treated. Such by-products, along with
food waste, spent grains and other
materials are classed as waste and need
a specialist license to be spread onto
farmland. Since their nutrient value varies
considerably, a sample analysis is vital.
Compost can be classed as a product
with no need for a license, provided the
supplier is regulated to BSI PAS100/QP
and the compost quality protocol. Like
paper crumble, it is a very bulky material,
making it a great soil conditioner. It may
have a very high total nutrient content,
but what’s available to the crop is
relatively low. Most of the N is locked
away and will be released slowly.
Compost is sometimes blended with
food waste, which alters the nutrient
make-up, but the material is now being
snapped up as feedstock for anaerobic
digesters (AD), with farmland benefiting
from the AD digestate by-product.
Like compost, AD digestate (also known
as biofertiliser) can be treated as a
product, not a waste, provided it’s
regulated to BSI PAS110/QP and the
AD quality protocol.
Pollution potential
Regulations governing how compost is
made and stored are also changing.
Unused corners at the edge of fields may
no longer be used for making compost.
The area now needs to have a concrete
bed and effluent storage capacity. “It has
the potential to pollute, just like a silage
clamp,” notes Peter Dampney. “Both
producers and farmers need to recognise
these materials are valuable, but they do
need to be treated in a responsible way.”
The end use for the crop should also
be considered –– sewage sludge can be
a particular concern here. “Scientifically,
it’s not a problem as the treatment and
monitoring biosolids receive ensures
they’re safe to return to the land
under the Sludge Matrix. But there
are maltsters and millers who don’t
want biosolids spread directly in front
of the crop they’re buying.”
That said, biosolids have a high N and
P nutrient value and high dry-matter
materials are good for SOM value too,
according to water companies.
Depending on the location and field
layout, some offer attractive deals,
especially to those prepared to take
material overwinter.
But timing can be an issue, notes Peter
Dampney. “In an NVZ, you’re restricted
from spreading slurries, poultry manures
and liquid digested sludge over winter
anyway. But a crop needs the nutrient in
the spring, which may not be the best time
to apply a more bulky material.”
Consider also what damage you could
be doing to your soil. “There are two
factors here –– ground conditions and
the machinery used. You need to have
control over the contractor so they
don’t spread the material after torrential
rain. And make sure high-tonnage
vehicles are adequately tooled up with
low ground-pressure tyres and twin
back axles.”
Finally, application accuracy is
important, stresses Peter Dampney.
“Solid manure spreaders distributing
from a central point need an overlap
approach to ensure an even distribution.
The more evenly the material is spread,
the better value you’ll get out of it,
and you’ll run less of a risk of nutrient
hot-spots which could lead to lodging.” ■
Turning rot to riches
AD digestate can be applied in the spring
like ordinary fertiliser, says Agrivert’s
Alexander Maddan.
Every year, Agrivert takes in 300,000t
of green material, food waste and other
organic matter and turns it into a rich
compost, spread on 12,000ha of farmland
around its bases near Newcastle in the
north east of England, and in Oxon.
Since January this year, the company
has also been an energy generator with an
AD plant producing 2.1MW annually from
40,000t of food waste, topped up with
whole-crop silage to keep a consistent
input feed line. The digestate by-product is
applied to local farmland, including a crop
of JB Diego that was harvested as whole
crop wheat to feed the AD plant.
“The digestate is like a 4% dry matter
slurry,” explains Alexander Maddan of
Agrivert. “We put it on in three applications
in the spring, just like a normal nitrate
dressing and the crop received no other
fertiliser inputs.”
Four-fifths of the plant’s by-product is
sold to other local farmers at £1/ m3, with
haulage and spreading costs on top.
The compost is sold for considerably more,
at £2.50/t, plus haulage and spreading
costs on top, but has a higher nutrient
and SOM value.
Over near Bristol, Hinton Organics takes
in 25,000t of green waste per year and
turns it into compost, with an AD plant
soon to come on stream. The firm carried
out some on-farm trials to establish the
value of the compost.
“We took on 40 acres (16/ha) of land
and compared the compost with ordinary
fertiliser over three years,” says the firm’s
Angus Cunningham. “It produced double
the yield difference
But demand and regulation is now
pricing agriculture out of the market, he
says. “We’re currently putting nothing on
to farmland. The demand from landscape
gardeners and housing has rocketed since
the restrictions on peat-based compost
came in. I can now sell it for £20/m3.”
New Environment Agency regulations
make it a very expensive material for
farmers, too. “There used to be a waste
exemption for composting sites used for
agriculture. Now it all has to be on concrete
and it’s moving under cover.”
The digestate is applied as a 4%
dry-matter slurry.