Nitrogen and sulphur timing in the Mallee

By Simon Craig (Agronomise, BCG consultant)

Key messages:

• The application of nitrogen increased grain yield by 0.5t/ha, but there was no benefit
  from additional sulphur. At this site, money was better spent on nitrogen than on sulphur.
• Grain protein was very low (7-10% protein) which is becoming an issue on sandy country despite adequate nutrition.
• The timing of nitrogen and sulphur applications made no difference to crop yield or quality. Consequently, growers could reduce production and financial risk by delaying some applications and adjusting rates to the seasons.

Last season, parts of the northern Mallee were fortunate to receive above average summer rainfall (in excess of 150mm in some places), setting growers in these regions up for an average to above average season. Optimism was somewhat dampened by a ‘super’ El Nino which was predicted to develop in August or September, casting uncertainty in growers’ minds. Consequently, management of crop inputs such as N and sulphur (S) presented some challenges.

In 2014, as part of the GRDC stubble initiative, BCG conducted a trial investigating the impact that N and S management in deep sands and how they influenced stubble height and composition. Although the initial aim of this project was to investigate the interaction between stubble and N and S inputs, the production data generated had relevance to nutrient management on sandy soils as it compared N and S timing this season.

The stubble project – maintaining profitable farming systems in Victoria and Tasmania with retained stubble (project number BWD00024) is funded by the GRDC.