26 October 2001

Direct drill, green style

A NOVEL design of direct drill could boost grower returns and conservation by reliably producing crops that yield as well or better than those from conventional or reduced tillage establishment techniques.

That was the message Dr John Baker of the Centre for International No-Tillage Research and Engineering, New Zealand, had for delegates at the recent World Congress on Conservation Agriculture in Madrid.

Poor direct drill coulter design has limited the success and uptake of non-tillage establishment in countries such as the UK and New Zealand, he maintains. But better coulter or "opener" design, such as his organisations Cross Slot opener, is changing that.

"Now, about 90% of all the arable crops that are no-tilled in New Zealand are drilled with the Cross Slot, and about 6% of arable crops are direct-drilled. Thats up from virtually zero three or four years ago and it is 100% down to the success of the Cross Slot."

That could be replicated in the UK, he believes. "Of the soils I have seen there isnt anything vastly different from regions where this design works well."

Seed is placed in a horizontal slit to one side of the opening slit made by the coulter, which overcomes the problem of trash folding into the opening slit.

Fertiliser, a key component for the success of direct drilling says Dr Baker, can be off-set horizontally or vertically from the seed placement. "The fertiliser needs to be close to the seed – our research has shown the best responses when it is off-set horizontally."

Dr Baker is keen to establish a grower group in the UK to test the system with an imported drill. Contact Dr Baker on bakerbnt@inspire.net.nz &#42

CROSS SLOT CLAIMS

Revolutionary coulter design.

More reliable direct drilling.

Matches or beats conventional yields.

UK grower group to test.

Independent question

Independent tillage consultant Steve Townsend, who was also at the Madrid conference, says it would be great if the Cross Slot could overcome the historical problems of direct drilling. But he questions whether UK weeds such as blackgrass could be controlled. "You need a stale seed-bed to reduce the grassweed populations. Thats why problems arose with direct drilling and minimum tillage in the past."

Independent expert unsure

Independent tillage consultant Steve Townsend, who was also at the Madrid conference, says it would be great if the Cross Slot could overcome the historical problems of direct drilling. But he questions whether UK weeds such as blackgrass could be controlled. "You need a stale seed-bed to reduce the grassweed populations. Thats why problems arose with direct drilling and minimum tillage in the past."