[Photo (left) by Brendon Cant: Six weeks in the field: No-till expert Rolf Derpsch.]
WA growers have well and truly
secured their place as innovators in Australia"s
agricultural history, especially with their
energetic adoption of minimum tillage from
the late 1970s. The Dowerin and Newdegate
field days became showcases for new ideas
and new machinery - often designed and built
on-farm - as the state"s graingrowers, backed
by new herbicides like the non-residual
knockdown Roundup, pioneered a whole
new farming system for Australian soils.
In the early 1990s when no-till began to
wane as yields appeared to be suffering and
there was concern about an over-reliance on
chemicals, a group of growers formed the
WA No Till Farmers Association (WANTFA),
believing the answers lay in pushing the
science and boundaries, not in retreat.
Their doggedness has led to an estimated
80 per cent of WA growers now using either
no-till or reduced tillage. The adoption
of the system nationally is credited with
significantly lifting the grains industry"s
sustainability. No-till growers talk
enthusiastically about the changing colour
and increasing softness of soils in which
organic carbon levels have been rising.
However, in recent years the benefits
of no-till have again appeared to plateau,
and earlier this year WaNTFA sought
help from world-renowned Paraguayan
no-till expert Rolf Derpsch.
After spending six weeks assessing
the situation, travelling 4000 kilometres
through WA and also South Australia
(with the SA No Till Farmers Association),
Mr Derpsch delivered a "good but
can do much better" report card.
In a nutshell, he said Australian growers"
flexible approach to no-till - using knife
points instead of discs to get that little
bit of extra soil turn, or still running
sheep - was compromising the system.
"I saw too much bare soil," he said.
Mr Derpsch said that for no-till to reach
its potential in Australia, rotations needed
to be more diverse. "Also, cover crops
should be incorporated to ensure that the
soil is covered 100 per cent of the time,
and discs need to replace tynes, so higher
rates of residue can be handled," he said.
Mr Derpsch said the advantages from
no-till farming came from constant soil
cover - not the actual tillage method.
North, South, West