TEMA: GØDSKNING
75 Graduated fertiliser application in England
TEMA: GØDSKNING
Graduated fertiliser application in England 75
75.1How
I use
use variable
variable application
application of
of
75.1
How I
nitrogen,
phoshorus
potassium
nitrogen,
phosphorus
and and
potassium
on my
farm om my farm
The English farmer Robert Fox has achieved good experiences from split nitrogen
application and he also graduates the application of P and K.
Farm manager Robert Fox
Squab Hall farm
Leamington Spa, England
E-mail: [email protected]
In England it has for a number of years been possible to subscribe to nitrogen application maps
based on NDVI from satellites, and to phosphorus and potassium maps based on soil sampling.
The farmer Robert Fox has achieved good experiences from split nitrogen application and he also
graduates the application of P and K.
Variable Rate Fertiliser Application at Squab Hall Farm, England
Squab Hall Farm is a 1000 ac arable farm 30 minutes south of Birmingham in England. I manage
the farm for the Evans family. Previously the farm was a dairy unit but the dairy herd was sold
back in the early 90s. The farm is made up of both owned and rented land of varying soil types
over a 6 mile radius. I am also responsible for the operations and agronomy on another 900 acres
between 3 to 7 miles away and have set up a machinery and labour share covering this acreage.
At Squab Hall we have always been keen to keep in touch with advances in crop application
technology and in the seven years I have been managing the farm we have taken up variable rate
fertiliser application in P and K and also Nitrogen.
The drive towards this was fuelled by lower crop prices and rising input prices coupled with the
fact that we, like most of England, were in a Nitrogen Vulnerable Zone and therefore we are
restricted in our use of Nitrogen fertilisers.
Variable P and K
Typical Phosphate levels in 2007
Typical Phosphate levels in 2011
The technology was in place through the recent upgrade of a tractor. This brought GPS technology
into the machinery fleet and the 2 year old fertiliser spreader was already compatible. Spreading
plans were created by the same company that carried out the soil sampling, SOYL, and loaded
into the fertiliser spreader controller. Cost savings were clear over a flat rate approach and
fertiliser use reduced by 30 %.
Variable Nitrogen
Once the practicalities of applying Phosphate variably had been learned and the application
technology proved, the logical step was to investigate variable Nitrogen application. Satellite
imagery was available to identify areas of the growing crop that were growing well and areas that
were not.
This Leaf Area Index map has been created from an NDVI
map from the satellite image. This is then converted into a
Nitrogen application map and loaded into the Fertiliser
spreader control box.
Variation was obvious from the
application models can be chosen.
outset
and
various
In order to prove the system to myself, in the first year
only 3 fields of Winter Wheat and one of Winter Oilseed
rape were spread under this method. Even in the low
yielding year of 2010, the yield benefit was clear in wheat
with an average of 0.2t/ha yield increase for no extra
Nitrogen use. In 2011 four fields of wheat were spread
On arriving at Squab Hall 7 years ago I found that like many farmers in the area, a “Phosphate
Holiday” had been taken due to low grain prices and relatively high fertiliser prices. The soils have
been sampled, some in 2007 and some in 2009 and the results were clear. Our heavier soils
seemed to be at acceptable levels for Potassium, but on some of the land Phosphate was clearly
deficient with indices at 1 and -1. However, patches of individual fields were at acceptable levels
so a variable rate approach seemed obvious.
2017
- produktion, natur og miljø
- produktion, natur og miljø
2017
TEMA: GØDSKNING
75 Graduated fertiliser application in England
TEMA: GØDSKNING
Graduated fertiliser application in England 75
variably with an average yield increase of 0.7t/ha with no extra Nitrogen usage. This gave me the
confidence to roll this system out over our whole Winter Wheat acreage and justify an increase in
our Nitrogen use.
Spreading Nitrogen variably from Satellite imagery has given the business I run clear financial
benefits, but it has its advantages and problems. The cost of the system is on a per ha basis so
you only pay for the area applied, but Satellite imagery can be unreliable due to weather and
other influences. The logical step for us now is to invest in a tractor mounted sensor to get a more
reliable picture of crop growth and also get images when we want.
2017
- produktion, natur og miljø
- produktion, natur og miljø
2017