Tuesday, January 03, 2012

“Go back!” CSIRO tells No-Till Tsunami

How Science greets farmer-driven innovation: The Case of No-Till

When King Canute commanded the waves of the ocean to retreat, he was trying to show his followers that he couldn’t command Mother Nature. Since Day 1, official science has tried to turn back the tide of no-till, and it is still at it. Despite no-till plateauing at 90% adoption in many districts, the CSIRO is advising farmers to get out the mouldboard and do some deep plowing. CSIRO farming systems agronomist John Kirkegaard told the 2011 World Congress on Conservation Agriculture in Brisbane that farmers shouldn’t be afraid of traditional cultivation.

He accused the no-till movement of adopting a rigid, purist approach to cultivation. “While everybody is striving to uphold the principles of no-till farming, at times it might make good sense to do some cultivation or to remove some stubble,” he said. “People might do a strategic cultivation to get lime into the soil,” he said.

Not so, says Bill Crabtree who has done more research on no-till than anyone else in 25 years, most notably as the Scientific Officer of the West Australian No-Till Farmers Association “Lime does not need tillage to move it to depth,” he reported in the GRDC-funded WAN3 and WAN6 Projects. (WAN3 - Scientific Officer Project or "No-till Systems Scientific Officer" for "The development and extension of no-till farming systems in WA" October 2002)

Bill, a scientist himself, reports encountering hostility from the science community in the early days of the no-till revolution: “The adoption was farmer driven. Much of the scientific data being presented during the time of explosive change, during the early 1990s, was negative towards no-tillage.” He says that there are too few progressive researchers:While no-till has been rapidly adopted by farmers, many researchers are still negative about no-tillage. This has restricted the amount of useful research that has been done. Many researchers are very quick to say

‘we told you so’ when problems emerge. It would be great if they said ‘let’s push on and refine the system to cope with the new challenges’. One thing is for sure, the farmers are not keen to go back!”

It appears that farmer-led innovation is immediately suspect to those who see their role as providing farmers with new technologies and techniques: “In the early 1990’s there was enormous farmer enthusiasm for the adoption of no-tillage… Some senior staff from the Western Australian Department of Agriculture (WADA) were not positive about this farmer enthusiasm and their rapid adoption of no-tillage. Farmers were frustrated by what they believed to be, a lack of objective WADA data that reflected their positive whole-farm benefits from their adoption of no-tillage.”

There was a lot to be enthusiastic about with no-till: “It has lifted whole farm yields, improved time of sowing, reduced evaporation, stopped soil erosion, lifted soil carbon levels, improved soil biological fertility (by not burning the soil with tillage), reduced farm energy inputs, and perhaps most importantly it has turned many of our soils into sponges with good soil structure. Making the soil biologically soft has helped us to maximise water use efficiency where water is scarce, and sometimes when intense rainfall occurs the water has been able to get to a depth where it is available for ‘drought proofing’…

“Yet, interestingly there was much resistance to this technology initially despite sound scientific data. It was a brave and exciting time to go against the convention on an idea that was obviously so right for so many reasons. They say, ‘change is first denied, then vehemently opposed before being accepted as self-evident’,” he said in his acceptance speech when receiving the prestigious McKell Medal in 2010 from the Natural Resource Management Ministerial Council. He is credited with being the main force behind no-till’s rapid expansion in Australia and the USA.

Dr Kirkegaard is one of the authors of the “farmers can’t afford to tie up the nutrients required to sequester carbon in soils” doctrine which uses a theoretical formula to ‘prove’ that a farmer cannot increase carbon levels and production without heavy application of inputs. (The Hidden Cost of Humus, GroundCover, September 2009).

But Bill Crabtree reported to the same Conservation Agriculture conference in Brisbane that biologically-active soils under no-till were being fertilized from a mystery source which raises questions over the established wisdom of how nitrogen replenishment works. Mr Crabtree said no-till farmers who had been unable to include legumes in their rotations were finding that soil nitrogen levels were not depleting as fast as expected.

“I have found that people who have kept all their stubble and not grown a legume in the system have more nitrogen in their soil than what we would expect them to have,” he said. “Some people will say they are getting the nitrogen out of the straw, but if the organic carbon is not going down across 10 years and you are harvesting 75 units of nitrogen (in the grain) every year and you are only putting on 25 units (in fertiliser) every year, then it has to be coming from somewhere.”

Mr Crabtree challenged scientists and researchers to investigate why nitrogen levels were holding up under legume-free, cereal cropping regimes. “Some scientists will think it is not possible to have a non-legume rotation and be fixing nitrogen,” he said. Mr Crabtree suggested there might be other factors at play in fixing nitrogen in addition to the known sources of lightning and rhizobial bacteria. “We know lightning can give you one or two kilograms of nitrogen. In the air we breathe there is 78 per cent nitrogen with bonds that are unbreakable except by lightning. The lightning will crack that open and that is why you get a little bit of nitrogen,” he said. “Or it can be broken open by rhizobia in legume crops like peas, chickpeas and lupins that fix nitrogen from the air. “The group of rhizobia bacteria aren’t the only ones that can do it. There are others that live in the soil that can do it.” Free-living bacteria and algae – and even stubble-eating termites – might be part of the nitrogen story.

“But the science community needs to work out why farmers are seeing what they are seeing. If we don’t there will be very good no-till farmers who get frustrated with the establishment who are disagreeing with them and they will go to ‘muck and mystery’ fertiliser companies and buy products that rarely add value to a farmer’s bottom line.”

Despite his reliance on ‘anecdotal’ evidence sourced from farmers, Mr Crabtree denies it to the farmer-driven innovation in the biofertiliser industry. Both Crabtree and Kirkegaard could be prisoners of their own paradigms, suspicious of bioferts as the next wave of farmer-driven innovation crashes on the rocks of othodoxy.

“There is a continuing need for farmers to take control of their own agronomic destiny. Researchers tend not to be leaders, but followers, and the lag phase is often very frustrating – especially when you are on the edge,” says Bill Crabtree.

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