Correlation studies between soil nutrients and plant nutrients and yield of Bt cotton growing soils of Kurnool district in Andhra Pradesh

The present investigation was carried out to study the delineation of nutrient status of Bt cotton grown soils in Kurnool district of Andhra Pradesh. Based on the status report of scarce rainfall zone, 2001 (Andhra Pradesh), the soils were identified into three predominant orders viz; Alfisols, Inceptisols and Vertisols. The soils were slightly acidic to moderately alkaline in reaction, non saline and medium to high in organic carbon. Regarding the correlation studies, all major, secondary and micro plant nutrients were positively and significantly correlated with respective available nutrient content of the three soil orders. Further, in Alfisols, soil K, S, Fe and Zn were not significantly associated with other leaf nutrients and soil Mg, Mn and B were positively significance with leaf Ca. In Inceptisols, soil N, K, Mg and S were not significantly associated with other leaf nutrients and soil Zn, Fe and Cu were negatively significance with leaf Mn. In Vertisols, soil P, K, Ca, Mg, Cu, Fe and Mn were not significantly associated with other leaf nutrients. Further, in Alfisols and Vertisols, soil N was positively and significantly correlated with yield whereas Alfisols and Inceptisols, soil P was positively and significantly correlated with yield.