Sulphur management in rice (Oryza sativa)–groundnut (Arachis hypogaea) to boost crop growth and system productivity

Nearly 44% soils in India and 36% soils in Odisha are deficient in sulphur (S). Both rice and groundnut respond well to S application. A field experiment comprising five sulphur fertilization methods, viz. no sulphur, 20 kg S/ha as bentonite sulphur, 20 kg S/ha as gypsum, 40 kg S/ha as bentonite sulphur and 40 kg S/ha as gypsum in rice allocated to main plots and three sulphur levels, viz. 0, 30 and 60 kg S/ha in groundnut allocated to subplots was conducted in a split-plot design with four replications during the kharif and rabi seasons of 2021–22 and 2022–23 at Bhubaneswar, India to assess the response of sulphur application on rice-groundnut system to. Application of 40 kg S/ha as gypsum to rice registered 24.2% grain yield increment (4.81 t/ha) over no sulphur. Likewise, in groundnut, an 18.4% yield increment was recorded with the application of 60 kg S/ha (2.05 t/ha) over no sulphur. Combined application of 40 kg S/ha as bentonite sulphur in rice + 60 kg S/ha in groundnut recorded the maximum system rice equivalent yield (11.21 t/ha), keeping 40 kg S/ha as gypsum in rice + 60 kg S/ha in groundnut at par. Rice grain yield and groundnut pod yield exhibited a significant positive correlation with dry matter accumulation and yield attributes of respective crops. Overall findings inferred that farmers should apply 40 kg S/ha as bentonite sulphur or gypsum in rice along with 60 kg S/ha in groundnut to boost crop growth and maximize system productivity in sulphur-deficient soils of Eastern India.