Long-Term Paddy Soil Development Buffers the Increase in Arsenic Methylation and Thiolation after Sulfate Fertilization.

Sulfate fertilization has been proposed to limit arsenic (As) mobility in paddy soils and accumulation in rice grains. However, As and sulfur (S) have complex biogeochemical interactions. Besides the desired precipitation of sulfides that sorb or incorporate As, S can enhance As biotic methylation and abiotic thiolation.