Sulfur Nutrition of Rice. I. A Survey of Soils of South Sulawesi, Indonesia¹

Abstract

Abstract Rice ( Oryza sativa L.) yields in South Sulawesi, Indonesia have declined in some areas despite the use of significant quantities of urea and triple superphosphate (TSP). Chlorotic plants were observed to be growing on these low‐yielding areas despite the application of N. A series of field trials were conducted to examine the S status of soils in the area. In these experiments S was applied in various forms and yields were measured from unfertilized, NP, and NPS treatments at each of 28 sites. Responses in rice grain yield to applied S were measured at 18 sites. The magnitude of the responses ranged up to 278% with an average grain yield response over the 28 sites of 18.6%. The widespread nature of the responses in soils derived from varying parent material and in different river basins suggest that some 60 to 70% of the agricultural areas of the province is deficient in S.