Long-term Influence of Intensive Cropping and Fertility Levels on the Build-up of Sulphur and its Influence on Crop Performance

The studies on long-term influence of four fertility levels and management practices under rice-wheat-sorghum and rice-mustard-mungbean rotations on soil fertility build-up and the yield of crops are being carried out in a Calciorthent. Increasing fertility levels significantly increased the crop yield and S uptake under both rotations. Depth-wise distribution of available S was also studied from the same experiment and the results revealed that high fertility level increased the available S at all the soil depths investigated. However, at medium and high fertility, available S was almost equal beyond 30–45 em depth under rice-wheat-sorghum rotation. Higher fertility reduced leaching losses to some extent. Accumulation of available Sunder rice-wheat-sorghum rotation was higher at all the depths as compared to rice-mustard-mungbean rotation due to higher amount of S added under the former rotation. However, S movement down the depth was more in case of rice-wheat-sorghum rotation. Rice-mustard-mungbean rotation removed more S from surface soil but at the same time it restricted the downward movement up to only 45 em. Under dummy situation at higher fertility levels, though the available S was higher at almost all the depths but there was slow movement of available S down the depth.