Nitrogen (N) nutrition of high yielding cotton crops remains one of the biggest production costs with improvement of nitrogen use efficiency (NUE) being somewhat of an enigma when trying to ensure that profitability and efficiency are both optimised. When attempts to improve NUE are centred on tweaking N rates, application timing and products only, the outcomes are frequently fruitless, confusing and seasonally contradictory. This is generally because they are made in the absence of close consideration of the other major factors that control NUE. NUE is not just related to N fertiliser practices but is intimately related to soil characteristics and condition, their reaction to irrigation practices, and weather conditions