Effect of Integrated Phosphorus Management on Macro and Micronutrient Status of Soil in Bt-Cotton

Abstract

Aim: To evaluate the impact of integrated use of phosphorus on soil fertility in Bt-Cotton. Study Design: The experiment was laid out in randomized block design with three replications. Place of Study: At College Farm, Agricultural College, Bapatla, Guntur district. Methodology: After the preliminary layout, Tulasi-BG II hybrid of cotton was used as a test crop, with a spacing of 90 cm x 60 cm in the experimental site. Farmyard Manure @ 10 t ha-1 was applied 10 days prior to sowing while phosphorus solubilising bacteria @ 5 kg ha-1 was applied one day before sowing. Phosphorus was applied as per the treatments basally at sowing whereas, the recommended dose of nitrogen and potassium (120 and 60 kg ha-1, respectively) were applied in four equal splits at 20, 40, 60, and 80. Results: The treatments showed no significant influence on available nitrogen and potassium but, comparatively higher values of nitrogen and potassium were observed in organic treated plots. The available phosphorus content was markedly influenced by level of phosphorus as well as components of integration at all the crop growth stages. Highest available phosphorus was recorded on integration of maximum dose of phosphorus with Phosphorus solubilising bacteria (PSB) and Farmyard manure (FYM). The available micronutrient contents in soil did not show any marked difference among the treatments at all the stages of crop growth. Conclusion: Application of phosphorus along with Phosphorus solubilising bacteria (PSB) and Farmyard manure (FYM) can reduce the phosphorus requirement to crops as well as improves soil health.