Integrated nutrient management for castor (Ricinus communis L.) - sorghum (Sorghum bicolor L. Moench) crop rotation in relation to tillage under rainfed Alfisol.

摘要

Cash-food crop rotation of castor and sorghum is predominant in rainfed Alfisols. Both crops are non-legumes resulting in no soil fertility build up. The dryland farmers cannot afford to meet the full-recommended rate of the nitrogen fertilizer to obtain maximum yield. Hence, integrated nutrient management (INM) is important. A field experiment, conducted in Andhra Pradesh, India, from 1999 to 2002, revealed that supplying 50% of recommended nitrogen to the crops through compost or gliricidia (Gliricidia sepium) lopping and 50% through inorganic fertilizer resulted in yields at par with 100% inorganic N and significantly higher yield than the treatment, which received no N. Ploughing was conducted without significant reduction in the yield of both the crops during all the years of the study. The interaction between INM and tillage was non-significant..