BCG is leading a five-year initiative that endeavours to increase the profitability and sustainability of farming systems by demonstrating how retained stubble systems can improve production and economic outcomes.
The GRDC-funded project, which was launched in 2013, is looking at all aspects of stubble management including its influence on crop establishment and growth, nutrition, soil health, pests, diseases, sowing and harvest logistics and crop sequences to manage stubble.
In partnership with Southern Farming Systems (SFS), Victorian No-Till Farming Association (VNTFA) and Irrigated Cropping Council (ICC), BCG will investigate and communicate practices that enable growers to retain stubble while maintaining profitable farming systems.
Crop residues, or stubble, play an integral role in soil health and nutrient cycling in broadacre cropping. However, for many growers, stubble can cause significant management issues that can affect their profitability. In these situations, growers are forced to remove the stubble, principally through burning.Â
There are also many other management issues that arise when stubbles are retained from one season to the next. For example, weeds, pests and stubble-borne diseases can cause problems in heavy stubble loads but can be managed without removing stubble.
One aspect of stubble management BCG is looking at, is the fate of nitrogen present in crop residues.
A research trial carried out at Horsham in 2014 and 2015 sought to discover how much nitrogen ends up in stable organic matter pools and how much, if any, is available to deliver benefits to subsequent crops.
To understand this, the trial plots were treated with N15 labelled fertiliser which allows the researcher to trace where nitrogen goes in the plant and the soil.
The N15 enriched residues have just been applied to subsequent crop plots; some to the soil surface, standing stubble, slashed stubble and some incorporated into the soil.
The N15 technology will enable researchers to see how much nitrogen is delivered to the subsequent crop and soil via crop residues and how much mineralisation of N occurs under a range of stubble management systems. Recommendations can then be made about the most appropriate and cost effective stubble management system for greater N mineralisation.
To find out more about stubble management and research, log on at: https://thestubbleproject.wordpress.com/Â
