Peter Hackett

Region: Mackay

Who: Peter Hackett

Location: Koumala

To improve nitrogen use efficiency

The Walkley-Black wet oxidation technique is the most widely used commercial assay to report soil organic carbon. For the sugar industry, the use of Walkley-Black organic carbon analysis is of significance. The industry endorsed BMP (Best Management Practice) utilises the ‘SIX EASY STEPS’ (6ES) nutrient management program. This program provides the industry with a set of soil and district-specific guidelines to manage N inputs based on a combination of district yield potential (DYP), organic carbon (%).

In the current 6ES framework, the contribution of N mineralized from soil organic matter available to the crop is based on the soil OC. Results from other sites have indicated a poor correlation between soil-organic carbon levels and potential soil mineralisation.

Because of this reason many growers are apprehensive lowering their Nitrogen rates to 6 Easy Steps level.
The trial will compare different rates of N application compared to the 6ES requirements for yields and NUE.