Performance of groundnut (Arachis hypogaea) under different levels of sulphur and irrigation

A field experiment was conducted on rice (Oryza sativa L.)–groundnut (Arachis hypogaea L.) cropping system during 2009, 2010 and 2011 at Chiplima, Sambalpur, Odisha to study the interaction effect of irrigation and sulphur on growth and pod yield of groundnut ‘Smruti’. The experiment was conducted in spilt plot design with three irrigation schedules viz. irrigation water: cumulative pan evaporation (IW:CPE) ratio of 0.6, 0.8 and 1.0, in the main plots and 4 levels of sulphur (0, 20, 40, 60 kg/ha) in the subplots. Phosphogypsum (18% S) was used as source of sulphur. Pooled mean pod yield of 3 years indicated that the highest pod yield of 1.80 t/ha was observed with application of 20 kg S/ha irrespective of irrigation schedules. From the response quadratic curve, the economic highest pod yield of 1.82 t/ha was calculated with 34 kg S/ha. The mean oil content increased with increased dose of sulphur and was highest (47.90%) with 60 kg S/ha. The highest mean sulphur use-efficiency was recorded with 20 kg S/ha and it was reduced with increased dose of sulphur. The highest pod yield of groundnut was observed with IW:CPE of 0.8, irrespective of sulphur doses, whereas the highest water-use efficiency of 4.32 kg/ha-mm was observed with IW:CPE of 0.6 and gradually decreased with higher irrigation schedule. The highest gross returns, net returns and benefit: cost ratio of 68,400, 42,500 and 2.64, respectively, were achieved with application of 20 kg S/ha.