Abstract

Two experiments were carried out to evaluate the effect of source and rate of sulphur (S) on yield and quality of a wheat (Triticum aestivum L.) crop and a permanent naturalized pasture in southern Chile. In the wheat trial, calcium sulphate (SCA) and magnesium sulphate (SMG) were tested (45 and 90 kg S ha -1). In the pasture trial, an additional potassium-magnesium sulphate (SKMG) treatment was considered. In both trials fertilizers were sprayed and a control treatment was included. In the wheat trial all aspects affecting yield components were evaluated: yield, nitrogen (N), phosphorus (P) and S concentration in plants and seed, and albumen quality were evaluated. In the pasture trial, the yield and nutritional quality (foliar concentration of N, P, S energy and "D" value) were evaluated. In wheat, S addition corrected soil deficiency but did not increase yield neither nor the quality (P > 0.05). In pasture, soil-S contribution and the type of the pasture employed masked the effect on yield and quality of the S-fertilizer added. No effect of the S source was found for the correction of soil S deficiency (P > 0.05) in the crop, or the pasture trial. Sulphur application increased plant P uptake. Sulphur soil deficiency correction in areas for wheat or pasture production The application of S in deficient soils is necessary to compensate for the estimation of negative gate budgets balances in the control treatments (-13 and -18 kg S ha -1). More studies are needed to establish the role of soil-S and leaching on S dynamics in andisols. © 2006 Instituto de Investigaciones Agropecuarias, INIA.