Direct and residual effect of sulphur fertilization to soybean-wheat cropping sequence

Field experiments were conducted during 2012 to 2015 to study the influence of direct and residual effect of sulphur fertilization to soybean-wheat cropping sequence. The location represents sub-montane zone of Maharashtra. It receives heavy rains in the months of July and August causing loss of soil and nutrients. The Treatments consisted of four levels of S (10, 20, 30 and 40 kg S/ha) to soybean croop in addition to the recommentded basal dose. The residual effect of applied sulphur was studied on wheat crop in the soybean-wheat cropping sequence. Increasing levels of elemental sulphur significantly increased yield, uptake and quality of soybean in the soybean-wheat cropping sequence. Application of 40 kg elemental S/ha recorded the highest values for the yield of soybean (30-7 q/ha) which was at par with 20 kg S/ha (29.1 q/ha) and 30 kg S/ha (30.3 q/ha). The residual effect of applied sulphur on the wheat crop also recorded similar pattern. The soybean equivalent yield recorded significantly superior yield of soybean due to sulphur application @ 20 kg S/ha (51.3 q/ha) over application @ 10 kg S/ha (47.3 q ha), while at higher levels of 30 and 40 kg S/ha the differences were not significant. The oil contents of soybean crop did not differ significantly due to the different levels of sulphur treatments; however, application of elemental S @ 20 kg S/ha significanty recorded superior oil yield (537 kg/ha) over S @ 10 kt/ha (481 kg/ha) and was at par with treatments of higher levels. Application of 40 kg S/ha recorded highest total N, P, K and S nutrients uptake and B: C ratio by soybean and wheat crop.