Cotton Productivity, Profitability and Changes in Soil Properties under Different Nutrient Management Practices

Abstract

Cotton is an important fibre crop of global significance, which is, cultivated in tropical and sub-tropical regions of more than seventy countries the world over. A field experiment was conducted during kharif, 2013 to evaluate the nutrient requirement of Bt cotton vis-a-vis fertilizer practices in vogue. At different growth stages, except control, all other treatments recorded higher number of monopodial and sympodial branches than 100% RDF. Incremental doses of fertilizers increased number of bolls plant-1 but very high doses practiced by farmers did not help in increasing boll number. Kapas yield increased with increasing fertilizer dose from 100 to 150% but was on par with the yield realized in 100% NPK and soil test based fertilizer application. Quality parameters like seed index, lint index and ginning out turn were not influenced by the fertilizer treatments. Availability nitrogen was lowest in control and highest in farmers’ practice. Availability phosphorus and potassium was lowest in control and highest in soil test based fertilizer application. Available sulphur content in soil was lowest in control and highest in 150% RDF + S @ 30 kg ha-1. Micronutrient status in soil at flowering and harvest stages was not significantly influenced by the fertilizer treatments. Economic analysis also indicated that application of very high doses of fertilizers did not help in getting higher net returns or higher benefit cost ratio. It is logical to resortof soil test based fertilizer application or to adopt the present recommendation of 150:60:60 kg NPK ha-1 for profitable cultivation of Bt cotton in Warangal district of Telangana state