Decisions used by NSW grains industry advisers to determine nitrogen fertiliser management recommendations

Abstract

Key findings •• Nitrogen (N) decision making requires a good understanding of background soil and plant science, and soil test interpretation. •• Training for new agronomists needs to be a priority issue. •• Senior NSW agronomists identified crop yield expectation as guided by soil moisture at sowing (or at the time of N decision making) as the most important determinant of N fertiliser requirement. •• Further research is needed to increase the understanding of how management practices affect potentially large gaseous N losses. •• Changing from legume pasture-crop sequences to continuous cropping in many central and southern areas of New South Wales is posing new questions for managing N supply. The absence of N-fixation by pasture legumes is seen as a substantial loss of N-buffering capacity. •• Despite most advisers choosing soil testing as a key approach for determining N fertiliser required, many of their clients had a lower confidence in soil testing, citing ‘high perceived variability in soil nitrate results in the lead up to sowing’.