Current Advances in Agricultural Sciences(An International Journal)

For addressing sustainability issues in cotton on a long-term basis, a field trial was carried out on a black clay loam (Vertic ustropept) at Coimbatore under irrigated condition during 1994 to 2005 with two most prevailing and popular cropping systems, viz. cotton-fallow and cotton-sorghum followed under continuous application of both organic manure and inorganic nutrient scheduling in the same site/lay out year after year. Initial slight alkaline soil (pH 8.71) was low in soil OC, medium in N and P, high in K and normal in both EC (0.64 dS m⁻¹) and sodium content (0.08%). Results revealed that cotton-sorghum cropping system maintained significantly higher seed cotton yield over the years in comparison to that in cotton-fallow system. Total cotton yield (based on equivalent yields) of 3.15 t ha⁻¹ was realized in the former in comparison to 1.02 t ha⁻¹ in cotton grown as monocrop. Similar was the case for sustainable yield index and productivity efficiency. Better performance of cotton following crop diversification in fact, was attributed to improved root growth(by 8%), higher growth and yield attributes (kapas plant⁻¹by 23%, bolls by 12% and sympodia by 6%), less weed growth (by 28%) and improved physical and chemical condition of the soil.

Integrated nutrient scheduling to cotton, viz. 30, 13 and 25 kg N-P-K ha⁻¹ plus FYM @ 5t ha⁻¹ could be sustainable over of range of nutrient nutrient schedules applied although one time basal application of P and K @ 19 and 37 kg ha⁻¹, respectively plus FYM @ 15 t ha⁻¹ produced more seed cotton over the years. Long term physical and chemical characteristics of soil were less influenced by the agronomic factors showing the soil resilience. Performance of crop in relation to fibre quality and others as influenced by long term management factors were again not conspicuous. Residual Sorghum as a bulk crop for fodder was not influenced by either of the treatments. It is established that irrespective of genotypes, diversification of cotton, and organics based integrated nutrient scheduling could able to nourish both crop and soils for long term sustainability.