Evaluation of Some Soil Test Methods for Measuring Available Sulphur in Alluvial Soils of Madhya Pradesh

In a pot culture experiment conducted with alluvial soils of Madhya Pradesh, a high degree of correlation of the sulphur extracted by mono-calcium phosphate solution containing 500 ppm P with sulphur uptake by lucerne plant (r=0.678) and the percentage yield (r=0.791) was obtained and 9.3 ppm sulphate-sulphur was observed to be the critical limit. Highly significant correlations between percentage yield and sulphate-sulphur extracted by potassium di-hydrogen phosphate solution (500 ppm P), 1% sodium chloride solution, water, 0.001 N HCl, Morgan's reagent and 0.15% calcium chloride were recorded. Relationship between sulphur in control plants and percentage yield was also found to be significant and most of the deficient plants contained less than 0.16 and 0.21% S in first and second cutting of lucerne, respectively