This Action on the Ground program assisted farmers and land managers to trial on-farm abatement technologies, practices and management strategies to reduce agricultural greenhouse gas emissions (methane and nitrous oxide) or sequester carbon in soil while maintaining or enhancing productivity. This project aimed to trial, measure and demonstrate on-farm practices/technologies that addressed the Round 2 Action on the Ground priority of reducing nitrous oxide emissions. BCCA locally coordinated this project with the support of BMRG, CQU, DSITIA, DAFF, FARMStuff and Wide Bay Composts.

Trials were in-place on two properties in the Monto district. The project trialled a number of variables in grain cropping systems to demonstrate how improving soil structure and reducing nitrogen fertiliser applications has the potential to decrease nitrous oxide (N2O) emissions. These variables included:

• the integration of legume rotations,
• the inclusion of soil amendments,
• minimum tillage practices,
• the use of nitrification inhibitors, and
• improved irrigation management and timing of fertiliser and compost applications.

The crop rotation system permitted legume crop treatments to be assessed multiple times over the duration of the project. Unfortunately, tropical cyclone Marcia destroyed the third-season crop of adzuki beans and mungbeans on both trial sites in early 2015. A winter legume crop of faba bean was subsequently planted to provide the second legume in rotation.

Some key outcomes from the trial found:

• N2O emissions increased following rainfall and irrigation events that caused water-logged soil for both summer and winter phases and in the legume phase, fallow ground consistently produced more N2O emissions then legume.
• Reducing urea application rates could reduce N2O emissions without affecting yield. Using a soil test to determine appropriate urea application rates was effective in achieving highest yields with reduced risk of N2O emissions.
• A fact sheet regarding N2O and the trial can be found here.