Effect of integrated use of farmyard manure and sulphur in a soybean and wheat cropping system on nodulation, dry matter production and chlorophyll content of soybean on swell-shrink soils in central India

In a 3-year experiment on a Typic Haplustert low in soil test sulphur (S), the response to applied farmyard manure (FYM) and S was studied in terms of the nodule production, nodule dry weight, chlorophyll content, dry matter production and seed yield of soybean. FYM was applied to soybean at four levels (0-16 t ha(-1)). S as gypsum was also applied at four levels (0-60 kg ha(-1)) to both soybean and wheat every year. Both total and active nodule production, nodule dry weight, dry matter production and seed yield of soybean were increased significantly by the application of both FYM and S. However, the proportion of total nodules to active nodules fell sharply for applications higher than 8 t FYM and 40 kg S ha(-1).