NESP TWQ Round 5 - Project 5.11 – Improved water quality outcomes from on-farm nitrogen management

Region map

The sugar industry occupies 350,000ha in Reef catchments, applies >55,000t of nitrogen (N) fertilizer annually and is a major contributor of dissolved inorganic nitrogen (DIN) to Great Barrier Reef receiving waters. There are many potential mechanisms for reducing on-farm Nusage. However, the comprehensive review of N use in sugarcane (SRA/DoE 2014) identified widespread over-use of N fertilizer and recommended adopting production zone yield potential (PZYP) combined with enhanced efficiency fertilizers (EEFs) to reduce ’surplus N’ (where applied N>crop requirements). This project utilized existing farm trials at identified N loss ‘hot spots’ to test PZYP as the basis for determining fertilizer N rates and for comparing EEFs with standard N fertilizers for minimizing N losses. Water quality benefits that derive from such practice changes were evaluated. Productivity, economic and environmental indicators validated these strategies for reducing surplus N and produced recommendations for enhanced Best Management Practices.

NESP TWQ Project Page 




10 March 2021

The dataset consists of tables of means, with statistical differences indicated where they are significant, for measured crop performance, fertilizer N recovery and use efficiency at 6 field sites from Mackay to Freshwater. Runoff losses of N are also shown from sites at Freshwater and Silkwood.

**This dataset is currently under embargo until December 2021.