Additional application of plant nutrients with farm yard manure for improving the adaptation of cotton crop to salinity stress

Cotton ( Gossypium hirsutum L.) is the world’s leading natural fiber, and generally considered moderately tolerant to salinity with a threshold level of 7.7 dS m -1 . Adequate regulation of plant nutrients can provide an important strategy to improve the adaptation of plants to saline environment. The present research was planned to investigate the role of plant nutrients in ameliorating the deleterious effects of salinity on growth, yield and fiber quality of cotton grown under salinity stress. Ten treatments comprising of nitrogen (N), phosphorus (P), potassium (K) and zinc (Zn) with and without farm yard manure at 10 dS m -1 electrical conductivity (EC) were arranged in completely randomized design with three replications. Results revealed that imposition of 10 dS m -1 EC increased leaf Na + concentration by 300% but decreased leaf K + by 46% and leaf K + : Na + ratio 87% with a subsequent marked reduction in growth, yield and fiber quality characteristics of cotton. The application of additional N, P, K, and Zn either alone or in combination effectively reduced Na + , increased K + concentration and K + : Na + ratio, leading to improved plant growth and yield. Among all treatments, higher ameliorative effects were observed for 100 mg N+75 mg P 2 O 5 +75 mg K 2 O+12 mg Zn kg -1 soil+ 5% FYM (w/w). This study suggested that nutrients-mediated reduction in Na + accumulation, increase in K + concentration and K + : Na + ratios were the main factors contributing to the improved adaptation of cotton crop to saline environment.