Cotton Research & Development Corporation is receiving low return on investment into N response trials in furrow-irrigated cotton. Nitrogen-fertilised paddocks are yielding not more than unfertilised paddocks in all but a few experimental settings, from plot to paddock scale. Yet at the farm system scale, growers see a nitrogen response, and likewise under overhead irrigation, measurable N responses are found in plot studies. The point of difference between studies where yield responses are, and are not, significantly measurable, is whether or not hydrological connectivity has the potential to transfer N from fertilised, to unfertilised soil. The industry needs a better understanding of the influence of hydrological spatial heterogeneity in furrow-irrigated systems on background soil N mineralisation and on conversion of fertiliser N.This project will use standard methods to map spatial variation in soil and soil wetness, and N supply from SOM in furrow irrigation systems used for cotton production, and investigate how this variation relates to measured soil mineral and mineralisable N on representative soil types for the cotton industry.

Dr Alice Melland

• Dr Alice Melland

• National Centre for Engineering in Agriculture

• Environmental Science and Management
• Other Agricultural and Veterinary Sciences

• Doctor of Philosophy (DPHD)
• Master of Research (MRES)