Cotton is currently cultivated in around 12.0 million hectares area, mainly in the arid and semi-arid regions of the country on swell shrink soils of central and south India and alluvial soils in the north west region. For centuries, cotton was grown without any external input. Fertiliser application began only in the 1950s, initially with the application of N alone. The concept of balanced fertiliser (N, P and K) began with the adoption of high yielding varieties and hybrid cotton. Several intensive nutrient exhaustive cropping systems became popular and consequently, secondary and micronutrient deficiencies started emerging in pockets. Rapid adoption of Bt hybrids during the last decade and escalating cost of fertilisers further necessitated a re-look into the nutrient management strategies in cotton. Today the emphasis is on matching nutrient supply with crop demand, site specific nutrient recommendations and incorporating the 4 Rs, namely, right dose, right time, right method and the right source. This paper traces the evolution of nutrient management strategies in cotton during the last six decades and enumerates the fertiliser best management practices (FBMPs) for the three main cotton growing zones in the country. Briefly, we discuss various good agronomic practices (GAP) that are needed to maximize nutrient use efficiency.
展开▼
