The largest change over the past 100 years in cropping has been from mechanical soil disturbance via disc and tine ploughing and sowing, the standard traditional method of crop production, sometimes involving up to eight passes over paddocks, to zero tillage.
It began in the 1970s, and initially for quite some time, farmers, agronomists and administrators were sceptical of zero tillage as a suitable cropping system.
Zero tillage to be successful involves herbicides to kill fallow weeds, minimal soil disturbance seeders, plus stubble retention instead of burning or ploughing into the soil early in the fallow period. Rotations to minimise new disease threats were required. New varieties with better disease resistance, avoiding weeds developing resistance to herbicides were needed. Plus, much new machinery technology.
A history of how the complex change to zero-till farming in northern NSW occurred has recently been documented by former researcher Jeff Esdaile. Titled, The Soil Revolution. The evolution of conservation farming in North West NSW, it is a detailed 109-page document. Scientific progress has previously been documented by others in technical agricultural journals. However, this publication records efforts by many farmers, agronomists and others to adopt conservation farming.
Jeff Esdaile was involved in zero-till research and adoption from the start. Initially based at Tamworth Agricultural Research Station (NSW DPI), in 1967, he transferred to be farm manager for Sydney University at the Narrabri Wheat Research Institute. He worked with Dr Bob Fawcett, pioneer and developer of the first soil moisture measuring probe, as well as assessing the role of preserving crop stubble, the role of disturbed soils, either tilled or untilled, for in-fallow moisture capture and storage.
In 1976 Jeff Esdaile became manager of Livingston Farm, a 4700-hectare property at Moree, bequeathed to Sydney University and for the next 24 years, he contributed enormously to the development and uptake of zero-till farming on a commercial scale.
In 1971 the Soil Conservation Service (SCS) started research at Gunnedah to address erosion in the expanding cropping industry. Their research assessed stubble burning, stubble incorporation, stubble retention and no-till treatments. Principal researchers included David Marston, Sheila Donaldson, David Thompson and Geoff Marschke. The research assessed issues like runoff, sediment, soil moisture and microbial activity.
A Northern Tillage Research Team was created in 1976 to coordinate research by the SCS, Department of Agriculture, CSIRO, and Universities of Sydney and New England. There were at least 15 researchers from various institutions working on zero-till related projects. Many national and international research papers were published via members of the team that also hosted visits by many international tillage experts.
Many farmers and agronomists are detailed in Jeff Esdaile's document as being major players in the progress and adoption of zero-till.
Some still are involved today. These include John Thomas (of John Shearer), Len Lillyman, Janke Australia, Monsanto (patented and released 'Roundup' in 1974), Warwick Felton, Harry Marcellos, David Herridge, Steven Simfendorfer, Andrew Verrell, Paul Nash, Kevin Moore, Peter Watt, John Kneipp, Brownhill family, Greg Rummery, John Gourlay, John Fahy, Doolin family, David Bailey, Dallas Parsons, Alan Hunter and Nixon family.
Benefits of zero-till development and adoption amount to $100s million a year, plus preserving the food resource base, our soil. Advantages include reduced erosion by 90 per cent or more, more water storage and capture, improved crop yields, more organic matter, better soil structure, soils more trafficable, preservation of earthworms and mycorrhizal fungi assisted, and optimum planting time is longer.
However, as Jeff Esdaile notes, zero-till has not been without its problems. Current and future research is required to address developing issues such as new disease situations, the need to build soil carbon and address weed herbicide resistance. The book is currently being prepared for publication.
Next week: Poor crop and fallow weed control, not weed herbicide resistance.
- Bob Freebairn is an agricultural consultant based at Coonabarabran. Email robert.freebairn@bigpond.com or contact 0428 752 149.
