Several factors influence the nitrogen demands of a cotton crop and the ability of the soil and fertiliser to satisfy these demands. Some of these factors (eg weather) are beyond the control of a cotton grower. One of the skills of cotton growing is having agronomy , especially fertiliser application strategies, that are least penalised by adverse conditions. Additionally, and especially during times of low prices, no grower can afford to miss any yield. This article outlines key principles arising from nutrition experiments and describes the options when deciding on fertiliser rates.