Management Strategies for Improved Productivity and Reduced Nitrous Oxide Emissions

Project Objective

Improve the management and nitrogen use efficiency (NUE) of key crop plants in cropping systems in three different environments, medium and high rainfall and under irrigation in order to reduce nitrous oxide emissions to the atmosphere.  The SA, VIC/NSW based project will use rotation, key nitrogen timings, nitrification inhibitors and crop sensing tools to optimize NUE and minimise N2O losses. The outcomes will be delivered via the farming group partners.

Project Outputs

The project outputs will be based on research trials, trial demonstrations days, extension of information via workshops, conferences and by electronic means, and a peer reviewed final report on the project. Outputs produced through these different channels will cover how different agronomic management strategies can be used to maximise nitrogen use efficiency and reduce nitrous oxide emissions in five key areas of broad acre crop management:

  • Use of legumes in the cropping rotation
  • Application of nitrogen fertiliser at key stem elongation growth stages
  • The use of precision farming tools to be better visualise nitrogen (N) mineralisation
  • Use of nitrification inhibitors
  • Where crops are irrigated

The outputs produced in this project will be:

  1. Research Trials
  2. The role of precision farming in reducing nitrous oxide emissions
  3. Trial demonstration days for cropping farmers and adviser
  4. Extension of project information
  5. Peer reviewed report

Role of SPAA in this Project

PA Assessment Input to Field Research Trials

SPAA will be responsible for the implementation of assessments involving PA related instruments at both sites. This is based on crop sensing equipment designed to better inform N management decisions. It is expected that at least five assessments will be made to the SA site and three visits to the Riverine Plains trial to take these measurements. Measurements will be made across all treatments with measurements informing N application to treatment 6. Where dry matter cuts are required at the time of crop sensing there is an expectation that SPAA will provide input to the assessment. In addition SPAA will be responsible any assessments using PA technology that could better inform N decisions with regard to better NUE and lower nitrous oxide emissions.

Rotation Position

At the Hart and Riverine Plains trial locations two six treatment trials will be set up in a wheat crop following two rotation positions:

  1. Following broad acre legume crop
  2. Following non legume break crop or cereal crop

Two trials with an identical treatment list as follows would be set up side by side in the two rotation positions on the same soil type, sown at the same time and managed in the same way in the 2014, 2015 & 2016 seasons. In order to set up in the correct rotation positions (legume break and non-legume break crop) two blocks of the appropriate size (no smaller than 50m x 100m) would be established in autumn 2014 and autumn 2015 in order to give a platform for the wheat trials in 2015 and 2016.

Treatment list for the wheat trials:

  1. Nil nitrogen applied (zero nitrogen control)
  2. Rate 1 – 40kg N/ha applied at first node (GS31) of the wheat crop (urea 46%N or UAN 42%N)
  3. Rate 2 – 80kg N/ha applied at first node (GS31) of the wheat crop (urea 46%N or UAN 42%N)
  4. Rate 2 – 80kg N/ha incorporated by sowing (urea 46%N or UAN 42%N)
  5. Rate 2 – 80kg N/ha applied at first node (GS31) of the wheat crop (urea 46%N or UAN 42%N) with nitrification inhibitor.
  6. Real Time Tactical Treatment – N timing and quantity at stem elongation determined by different crop sensing tools using Normalised Difference Vegetative Index (NDVI) to assess chlorophyll content and biomass. Overall responsibility for this treatment (trt 6) rests with SPAA so co-ordination Sam Trengove is essential.

Exact quantities of nitrogen for rate 1 and rate 2 will be determined by a soil nitrogen test at sowing with a soil test at GS30-31 (untreated crop & treatment 4)

PA Assessments of SA and VIC/NSW Trials (to be conducted by SPAA)

Final Data Analysis and Reporting

SPAA will provide an annual and three year report (tabulated data and brief outline of methodology and treatment 6 details) from each site that will assist in producing annual project and final report.

Extension of Results and use of SPAA Communications to its members and non-members (based primarily on field days & results conferences/workshops – expectation of being involved in at least 2 events per annum)

In spring 2014 the trials would be showcased at the farming group field days where SPAA would be involved. The trial would be outlined, strategies for N2O emissions outlined and any early results outlined. This would be repeated in spring 2015 and 2016 with new aspects of the project being focussed on in order to give fresh appeal. From winter 2015 results from the project would be outlined at farming results conference or a specific workshop. The plan would be to run three events with each farming group and or SPAA that extended the results to a broad body of growers and advisers during the winters of 2015-17. The promotion of these events and opportunities to present results would be the responsibility of SPAA in conjunction with the farming group. Co-ordination with FAR Australia and the farming groups would be desirable in order to structure an events calendar at the start of the year. Results would be presented by Hart, SPAA and FAR Australia research teams with select events drawing on the expertise of QUT technical staff. The advertising and general communication of these events and project aims would be the responsibility of SPAA and farming groups.

Attendance at Annual Steering Committee Meetings

To attend and present findings to the steering group as part of the process of managing of assisting in managing the project. Steering group meetings are provisionally scheduled for July 2014, 2015 and 2016, however since there are no results available in 2014 the first meeting maybe held in 2015.

Placement of an Annual Article in the SPAA Magazine

Using data collected by SPAA from DAFF project, SPAA in conjunction with FAR Australia to place an article in the SPAA magazine based on use of precision farming tools to reduce nitrous oxide emissions in the cropping sector.

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