Don’t Wait for Rain, Drill Now
March 12, 2013
A leading world authority on soil science is recommending that, even in severe drought conditions, farmers should be
drilling new seed now.
Dr John Baker says even after weeks of drought, seeds can still survive in the ground until the weather breaks. He
explains that dry sowing is common in Australia and even Wairarapa.
There could still be moisture vapour in the soil even if there’s no usable liquid moisture present he says. But even if
there’s no moisture vapour the seeds won’t come to any harm until it rains.
If the paddock had a reasonable cover of grass before the drought struck or there’s crop stubble present, then drilling
into the dead mulch will be a smart move. The moisture vapour under the dead vegetative material will be trapped and
offer sustenance to seeds which can survive as sub-surface seedlings if sown in inverted-T shaped slots for up to nine
weeks before emergence.
Dr Baker, who has a MAgrSc in soil science from Massey University and PhD in agricultural engineering, has researched
and developed Cross Slot no-tillage drills which penetrate through the crop residue on top of the ground and sow seed
and fertiliser in different bands at the same time.
His drills are used extensively in the prairies of the United States and Canada and in the dry soils of Australia. Now
New Zealand is experiencing the same sort of drought conditions Dr Baker points out.
The Cross Slot process causes minimal or low disturbance to the soil, traps the humidity, preserves the micro-organisms
and soil life and largely prevents carbon from escaping into the atmosphere. Further, by leaving the stubble and straw
from the previous crop to decompose on the surface of the ground, it helps sequester new carbon in the soil.
No-tillage is the equivalent of keyhole surgery as opposed to ploughing which is invasive surgery and contributes to
global warming. The result of no-tillage is increased yields, the near elimination of crop failure and soil erosion and
sustainable food production which can feed millions of families.
Dr Baker has long advocated the greater use of no-tillage in New Zealand because, in drought conditions, traditional
methods of ploughing are ineffective. He also predicts that, if conventional ploughing isn’t replaced by no-tillage
within 50 years, there’ll be famine and drought in large areas throughout the world.
With reference to New Zealand’s drought he recommends that, by drilling seed now, farmers can buy it at affordable
prices and have a better chance of hiring a no-tillage contractor when the rains come.
“When it rains you’ll have vigorous pasture growing several weeks before most people get around to buying seed let alone
drilling it. In any case seed might then be in short supply and will almost certainly be more expensive than at the
moment,” he comments.
However he points out that no-tillage isn’t just an option in times of drought but in preserving carbon in the soil.
“Carbon is a vital ingredient of soil. Plants that we eat all contain carbon. When they die they decompose and
earthworms and other microbes take the products of decomposition, which are rich in carbon, into the soil and keep them
there.”
“When the soil is ploughed it releases much of the carbon back into the atmosphere. The long term result is a reduction
is soil organic matter which, in turn, leads to soil erosion, dust storms and ultimately famine. Nothing improves the
water holding capacity of soil more than organic matter and that is never more important than in a drought.”
Dr Baker has been nominated for this year’s prestigious World Food Prize in the United States and his machines were a
finalist in the World Technology Awards two years ago. His Cross Slot drills are recognised by the United Nations Food
and Agriculture Organisation (FAO) and the United States Department of Agriculture as the best in the world.
ENDS