Tours highlight diversity of non-wetting options
Western Australian grain growers on fact finding bus tours to view systems used by their peers to alleviate non-wetting soils learned that there is no ‘single bullet’ answer to the soil constraint.
“Growers observed that in many circumstances, a mix of methods can work best,” Grains Research and Development Corporation (GRDC) Regional Cropping Solutions Network (RCSN) coordinator Julianne Hill said.
Ms Hill coordinated the two tours in WA’s northern and southern cropping regions which visited farm paddocks and small plot trials on a range of soil types and in different rainfall zones.
“The tours looked at a range of methods that farmers are using to help manage non-wetting soils, which have been identified by the GRDC RCSNs as heavily affecting the profitability and productivity of most WA growers,” she said.
“Leading non-wetting researchers from organisations including the Department of Agriculture and Food and CSIRO, as well as consultants, participated in the tours to lend their knowledge to farmer participants.”
Ms Hill said many of the host farmers visited estimate that up to 90 per cent of their land is non-wetting.
“Its effects can include poor crop germination, staggered weed germination (making weed control difficult) and an increased risk of water and wind erosion,” she said.
“On or near row seeding, delving, spading, mouldboard ploughing, discs, different sowing boots, wetting agents, claying, liming and more have been tried by the host farmers, with many opting for a mix of methods to overcome their problem soils.
“Regardless of the method they used, host farmers often stated that even though it was costly to manage non-wetting soils, increased returns in the first year alone were often enough to justify the initial outlay.”Ms Hill said tour participants received a copy of a new non-wetting farmer case study booklet edited and compiled by the South East Premium Wheat Growers Association (SEPWA).
The booklet, which features most of the farmers visited, can be downloaded at www.grdc.com.au/GRDC-Booklet-CombattingNonWettingSoils.
Non-wetting researchers Margaret Roper, of CSIRO, and Stephen Davies, of DAFWA, said the tours demonstrated that non-wetting soils could be successfully ameliorated by many, often completely different options, ranging from minimum soil disturbance to mouldboard ploughing.
They said soil types and other factors such as weed issues or soil acidity influenced the systems most appropriate to use in a particular situation.
Dr Roper said the use of claying, commonly used in WA’s southern cropping regions, seemed to provide a virtually permanent fix for non-wetting soils if done correctly and also improved the stability and structure of the fine sands in these areas.
“Some farmers are also using near-row and zero or minimum disturbance seeding systems to allow water to penetrate old root pathways and be taken up by crops,” she said.
DAFWA non-wetting researcher Stephen Davies said some growers with ‘forest gravel’ soil types were using banded wetting agents, often in combination with on-row seeding, to achieve improved ‘wetting up’ and crop establishment.
“By viewing other farmers’ non-wetting problems and management approaches, tour participants were able to categorise their own non-wetting issues and think about the diverse array of options suitable to their circumstances,” he said.
Other findings highlighted during the tours included:
- Know what is under your topsoil, particularly if you are thinking about mouldboard ploughing or spading (hostile subsoils are better left untouched in most cases)
- Test clay before using it as a soil ameliorant
- Don’t sow canola in the first year after mouldboard ploughing
- Finding the best fit for wetters is still to come and more work can be done on this
- Options such as seeding on row or under row are usually cheaper and more effective for establishing crops on non-wetting soils but don't fix the soil repellence problem. In southern parts of WA, these options seem to be working well on a number of farms.
Julianne Hill, GRDC RCSN coordinator
0447 261 607
Stephen Davies, DAFWA
08 9956 8515, 0408 439 497
Margaret Roper, CSIRO
08 9333 6668
Natalie Lee, Cox Inall Communications
08 9864 2034, 0427 189 827
GRDC Project Code KW/Alb 12/13JointProj