Enhancing soil productivity for crop and pasture production is a priority for most farmers, but particularly Mallee grain growers who have vulnerable sandy soils. Agronomic practices and farming techniques that minimise soil erosion can play a pivotal role in minimising the risk to soil health.
In recent years, soil science has shifted its focus from investigating the properties and structure of Mallee soils to developing tools and strategies farmers can adopt that will allow them to improve the health of their soils and subsequently maximise yield and productivity.
Farming systems such as controlled traffic farming (CTF), which supports zero and minimum tillage, has the potential to increase yields, reduce production costs and improve soil health. According to a report on ABC Rural Country Hour on March 11, 2014, the additional aeration achieved from the use of control traffic methods, can boost yields by up to 15 per cent in Mallee soils.
CTF restricts the movement of vehicles to set paths through paddocks. The aim is to reduce soil compaction, decrease leaching of nutrients, reduce water erosion, improve infiltration and control run-off (GRDC).
Thanks to the wide adoption of satellite guidance systems on farm machinery, by default, most Mallee farmers have implemented part of a controlled traffic and/or precision agriculture system in their farming business.
The tendency of modern farmers to control summer weeds better than they might have done prior to adopting a no-till or minimum till farming system has also benefited both soil health and crop productivity.
BCG trials coordinator Claire Browne said that a five year BCG research project found that grain yield increased each year when summer weeds were controlled and there was also a healthy return on investment.
“Uncontrolled weeds rob water and nutrients from the soil that could be later used by the crop,” she said.
A consequence of thorough summer weed control can be a reduction in groundcover, exposing vulnerable Mallee soils to wind erosion. Fortunately, summer weed control practices tend to go hand in hand with stubble retention farming techniques which help to alleviate some of the erosion risk. Nevertheless, consideration needs to be given to soil management practices that will both protect and enhance soil health and the sustainability of farm land.
This project was commissioned through the Mallee Catchment Management Authority and funded through the Australian Government. For more information on the project visit the BCG or Mallee CMA websites.
References: GRDC controlled traffic farming factsheet, July 2013.
