Sustainability of sunflower-based crop sequences in rainfed alfisols

Abstract

A field experiment was conducted at Hyderabad, India, for six years (1992 to 1997) to study the performance of rainy season sunflower at 50% (37.5:45:15kg N:P205:K20/ha), 100% (75:90:30kg N:P205:K20/ha) and 150% (112.5:135:45kg N:P205:K20/ha) recommended NPK in annual rotation with rainy season crops viz. sorghum (Sorghum bicolor (L) Moench), pigeonpea (Cajanus cajan (L) Millsp), groundnut (Arachis hypogaea. L), sunflower (Helianthus annuus L) and castor (Ricinus cummunis L). The study also dealt with the productivity economic returns and sustainability of the crop rotations. The fertilizer levels did not vary the seed yield of KBSH-1 sunflower over the years. Application of recommended dose of fertilizer to base crop resulted in higher yield of succeeding sorghum, pigeonpea, sunflower and castor, while 50% reduction in recommended dose of NPK to base crop recorded higher yields of groundnut compared with the others. The higher sunflower seed equivalent yield was obtained with groundnut and sorghum as sequence crops. Sunflower-groundnut rotation gave the highest net returns (Rs.17,987/ ha) followed by sunflower-sorghum system (Rs.15,457/ha). The study revealed that the sunflower-groundnut cropping system was more sustainable (44.24% SYI) followed by sunflower-sorghum system (37.52%) under rainfed alfisols.