FARMER CASE STUDY
SEEP REHABILITATION IMPROVES PRODUCTIVITY
SNAPSHOT
Managers: Brothers Philip and David
Smith
Location: Geranium, SA Mallee
Area: 541 hectares
Annual average rainfall: 400 millimetres
Soil types: Dune and swale
Enterprises: Cropping, sheep
Crops: Wheat, barley, canola, triticale,
oats
RIGHT: The Smiths have
established lucerne on the
paddock to the north of
the dune.
FAR RIGHT: As the
waterlogging gradually
reduces, the cropping area
is gradually expanding into
what was a soak area.
Planting trees, salt-tolerant plants and lucerne have
mitigated a historic seep area for the Smith family in the
South Australian southern Mallee.
David Smith and his brother Philip bought their Geranium
property with a 10-hectare soak area in 1990.
“Before we bought the property, the previous owners
used the area for mud-sliding in buggies,” David said.
“There was no way you could crop on there, the ground
was so boggy and the soil was saline. It would get boggy
after any rain, even in summer.”
Two paddocks adjoin the soak area — pasture on the
north side incorporating a sand-hill and prime cropping
swale to the south. When the family took over the area,
the sandhill was bare and the paddock to the north sowed
to pasture. The south paddock is continuously cropped,
with sheep grazing stubbles in summer.
The family wanted to do something more useful with the
soak area so David started rehabilitation about three years
after they took over.
“First we fenced off the side of the hill, where the seepage
originates, and planted about 500 trees in 1992 to use
up more of the moisture before it could seep,” he said.
“It wasn’t a big project, we only had to fence about 1.5
kilometres and we got a group of friends together to plant
the trees.”
KEY POINTS
LEFT: Lucerne
established
directly above
the soak area,
providing deep
rooted water use
year round and
valuable summer
grazing.
• David and Philip Smith rehabilitated
a soak area during the 1990s
• The family planted trees, puccinellia
and tall wheat grass
• They have now reclaimed six
hectares of prime cropping land
“Next we planted some salt-tolerant and
waterlogging-tolerant plants at the bottom of the
soak, including puccinellia and tall wheat grass.
We never had to fence off that area, the sheep
grazed them from the first summer but it never
seemed to compromise the growth.”
The Smith’s prompt action prevented the seep
area from degrading. Without this cover, the soil
moisture would have evaporated at the surface
causing salt to concentrate at the surface. If this
process had been allowed to continue for long
enough, the topsoil would eventually become too
saline for cereal crop growth to be re-established.
The Smiths reintroduced sheep to the tree zone
after about five years and then in a good season
about 10 years ago, established lucerne on the
top of the sandhill.
“We saw results from the first year after we
planted the trees and plants. It was less boggy
straight away. But we’ve also seen a gradual
improvement over time including after the
lucerne was established.”
Philip now farms the property and says that from
starting as a sceptic, he has been able to reclaim
close to six hectares for cropping.
“When the trees were first planted, I must admit
I thought it wouldn’t make much difference,”
he said. “But for an area that was absolutely
useless before, I can get a great crop on the four
hectares of reclaimed land and I have just started
reclaiming some more.”
Philip reclaimed two hectares two years ago,
planting barley in 2014 and triticale in 2015.
While the area is not yet growing a good crop, it
is improving and he hopes the deep roots of the
triticale will help develop some organic carbon to
improve the soil structure for 2016.
Philip has also recently fenced off the lucerne
sandhill to optimise the grazing.
“The lucerne was too easy to over-graze and it is
important we keep it growing so it holds the soil
together. I fenced off about two hectares and now
I just open the fence for the last three to four days
of grazing the bigger lucerne paddock.”
MORE INFORMATION
CONTACT: David Smith, 0427 857 722 and Philip Smith, 0428 736 548
FACT SHEET: Managing Mallee Seeps available from www.msfp.org.au
MSF: 03 5024 5835 and [email protected]
WEB: www.msfp.org.au
This case study was published in February 2016
MSF would like to thank Chris McDonough, Insight Extension of Agriculture, the GRDC, and Natural
Resources SA Murray-Darling Basin for their support in producing this case study