IF you are planning to switch to controlled traffic farming (CTF), deep tillage should be your first management strategy.
Department of Primary Industries and Regional Development (DPIRD) research officer Wayne Parker told the conference extensive trials had demonstrated consistent yield improvements from marrying the two practices.
“Deep ripping acts to loosen the soil while decreasing density and soil strength to allow roots to grow more freely in the absence of other constraints,” Mr Parker said.
“Increasing rooting depth increases the volume of soil the plant is able to explore for moisture and nutrients.
“This effectively increases the ‘bucket’ of water available to the plant that can be used to produce grain.
“In this way, deep ripping helps to improve the water-use efficiency through using more of the soil moisture.”
And trials at Binnu, Moora and Munglinup on sandy soils and sand-over-gravel, where deep ripping was combined with CTF, have maintained significant yield responses over the past two years.
Mr Parker said it was imperative to manage paddock traffic to maintain the economic benefit of deep ripping.
“This includes keeping every farm implement – whether it be harvesting, seeding or spraying – off the paddock, permanently confined to wheel tracks and prevent soil compaction,” he said.
“One pass of an implement is sufficient to return deep ripped soil to 80 per cent of its strength before ripping.”
Trials co-funded by the Grains Research and Development Corporation are continuing this year at eight sites throughout the Wheatbelt, measuring the influence of controlled traffic on maintaining yield responses to deep ripping.
Mr Parker also said that while the benefits of deep ripping sands were well known, trials had also shown yield benefits on clay soils with sodicity at depth.
“The deep ripping trial at Ongerup on gritty, grey clay, has shown a benefit from using topsoil slotting plates behind the tines,” he said.
“We have seen consistent yield benefits of up to 40pc in barley at this site.
“The presence of sodium ions in the clay at this site increases with depth to toxic levels at 300 millimetres (12 inches).
“But the use of slotting plates creates a narrow opening behind the tine, enabling topsoil organic matter to be mixed to depth, providing a buffer to the sodicity and a pathway for plant roots to penetrate the soil.
“In the trials, this resulted in both better water-use efficiency and increased return on investment.”