Effect of organic manure and sulphur fertilization in pigeonpea (Cajanus cajan) + groundnut (Arachis hypogaea) intercropping system

There is large number of sulphur(S) sources available in the country and their efficiency need to be evaluated. In view of the meager information available on sulphur nutrition in a popular intercropping system of pigeonpea + groundnut. A field experiment was conducted during kharif 2003 and 2004 to evaluate the response of pigeonpea [ Cajanus cajan (L.) Millsp.] + groundnut ( Arachis hypogaea L.) intercropping system to FYM and S fertilization. Ap- plication of FYM at 5.0 t/ha significantly increased the yield and yield attributes, nutrient (NPK) uptake in pigeonpea and groundnut, system productivity (1.71 t/ha), net returns (Rs 18,287) and available S in soil after har- vest (15.72 kg/ha). However, B: C ratio was higher with crop receiving no FYM. Intercropping failed to influence the yield attributes, yield and nutrient uptake in pigeonpea, however, system productivity, net income and B: C ra- tio was higher in pigeonpea + groundnut system. The available soil S after harvest of crop(s) was lower in pigeonpea + groundnut system (13.11 kg/ha) when compared with sole pigeonpea (17.06 kg/ha). Application of sulphur at 35 and 70 kg/ ha, being on par, recorded significant increase in yield and nutrient uptake in pigeonpea and groundnut, system productivity and total net income over no S. The available soil S after harvest of crop (s) was higher with 70 kg S/ha. The S use efficiency indices were higher at lower i.e. 35 kg S/ha. Among the sources of sulphur, cosavet recorded higher yield and yield attributes, nutrient uptake and S use efficiency. However, the highest soil available S at harvest (19.34 kg/ha) was recorded with elemental S applied at 70 kg/ ha, while the highest net income (Rs 20,431) and B: C ratio (2.0) were achieved with gypsum at 35 kg S/ha.