MINERALIZATION OF SULFUR FROM FOUR SOILS AND ITS RELATIONSHIP TO SOIL CARBON, NITROGEN AND PHOSPHORUS

The mineralization of soil sulfur, as measured by calcium chloride extraction of fresh samples, was compared and discussed with carbon-dioxide-evolved, nitrogen mineralized, sodium-bicarbonate-extractable phosphate, lipid phosphorus and arysulfatase activity. The amount of sulfur mineralized after 14 wk was compared with various initial soil values, such as the form of sulfur and ratios among C, N and S. In general, the samples with larger C:S and C:N ratios resulted in lower sulfur- and nitrogen-mineralizable values; however a complex interrelationship among C, N and S was evident. A high N:S ratio (produced by addition of nitrogen) resulted in a decrease in mineralization of sulfur in the soil sample during an 8-wk incubation.