This case study (part of the CottonInfo case study series) looks at the use of nitrogen in cotton production by comparing the outcomes of Cotton Seed Distributor variety trials and CottonInfo regional development officer in-field nitrogen trials. The resulting data indicates a reduction in the amount of lint produced in proportion to increased amounts of N applied (ie. lower Nitrogen Fertiliser Use Efficiency or NFUE): not a good scenario when N is one of the biggest costs in cotton production.