Practical solutions to optimise nitrogen use efficiency within modern surface irrigated cotton systems in Australia may be possible by regulating the frequency of water and reducing the N applied, compared with typical current practises. A two-year study examined the effect of irrigating at three different water deficits that applied a similar total irrigation volume: >−60 kPa (HF), between −80 and −100 kPa (IF) and between −100 and −120 kPa (LF) for a period from initial flowering throughout boll development, in combination with different nitrogen fertiliser rates on the growth, yield, nitrogen use efficiency and lint quality of cotton. It was hypothesised that shorter deficits would increase N uptake, and nitrogen use efficiency compared with longer deficits caused by consistently higher soil water potentials in the root zone. The major effects of irrigation treatment on growth was to increase plant height and number of bolls, delay crop maturity and decrease micronaire. The irrigation strategy according to yield was most consistently optimised over both seasons when soil matric potential was maintained between −80 and −100 kPa (IF treatment). Lint yield was reduced by 9–13% when the irrigation deficit was <−100 kPa. The most efficient fertiliser use varied between the two years but was always lowest in the treatment with the highest deficit. Irrigation deficit did not change nitrogen uptake or internal nitrogen use efficiency. Nitrogen, even at rates substantially lower than typically used commercially, did not affect fibre quality. There was no interaction between irrigation strategy and N fertiliser rate on yield, fibre quality and fertiliser use efficiency.

与典型的现行做法相比，通过调节水的频率并减少施用的氮，可能在澳大利亚的现代地面灌溉棉花系统中实现优化氮利用效率的实用解决方案。一项为期两年的研究检查了在三种不同的缺水情况下灌溉的效果，这些缺水应用了相似的总灌溉量：> − 60 kPa（HF），− 80至−100 kPa（IF）和−100至−120 kPa（ LF）从初花期到整个铃铃发育期，再结合不同的氮肥用量，对棉花的生长，产量，氮素利用效率和皮棉质量都有影响。有人假设，与根部土壤水势持续较高引起的亏缺时间相比，亏缺时间短会增加氮素的吸收和氮的利用效率。灌溉处理对生长的主要影响是增加株高和棉铃数量，延迟作物成熟并降低马克隆值。当土壤基质势保持在-80和-100 kPa之间（IF处理）时，根据产量的灌溉策略在两个季节都得到了最一致的优化。当灌溉亏<<-100 kPa时，皮棉产量降低9-13％。两年间最有效的肥料使用量有所不同，但在赤字最高的处理中始终最低。灌溉不足并没有改变氮的吸收或内部氮的利用效率。氮气，即使速率大大低于通常在商业上使用的速率，也不会影响纤维质量。灌溉策略和氮肥用量对产量，纤维品质和肥料利用率之间没有相互作用。