Utilization of applied sulphur-35 by wheat and ''A'' values of sulphur as affected by nitrogen application

Field studies were conducted on wheat (var. Kalyanasona) to study the utilization of applied sulphur and the 'A' values of soil sulphur as affected by the application of nitrogen, using 35S, in a sulphur deficient black soil from Jabalpur. The grain yields significantly increased with increasing levels of nitrogen but not with higher levels of applied sulphur. The percent utilization of applied sulphur decreased significantly by a dose higher than 20 kg S/ha, but increased significantly by the levels of nitrogen up to a dose of 125 kg N/ha. 'A' values of soil sulphur increased by the application of sulphur, but decreased by the levels of nitrogen. The grain yields were related to the percent utilization of fertiliser sulphur but not to the 'A' values of soil sulphur. Partial correlation studies indicated that 'A' values of the soil sulphur contributed towards grain yield up to 60 days growth of wheat plant and the fertilizer sulphur in the later part of the growth. Percent utilization of fertilizer sulphur was negatively related to the 'A' values of soil sulphur. (author)