Effect of elemental and soluble sulphur sources on grain yield of wheat (Triticum aestivum L) in Mollisols of Pampas Region of Argentina

摘要

Field experiments were conducted in different sites of the humid area of the Argentine Pampas Region during two successive years. The objective was to evaluate the influence of different sulphur sources (elemental and sulphate form) on grain yield ofwheat (Triticum aestivum L.). This region has a temperate climate; average annual rainfall is 980 mm and mean annual temperature 16°C. The S sources used in the experiments were: micronized elemental sulphur (ES, 95% of S) and standard ammonium sulphate(AS, 21-0-0+24% of S). A randomized complete block experimental design with 4 or 6 replications was used with factorial arrangement. Factor 1 was sulphur source and factor 2 was the S rate. Sulphur rates were 10 and 30 kg/ha (year 1) and 15 and 30 kg/ha(year 2). A check treatment was included. Data were analyzed through factorial analysis of the variance (ANOVA). There was a significative fertilization effect (p<0.05) in 80 % of sites and response was in the range of 231-857 kg/ha (mean response=600 kg/ha) during the first year. During second year a significant response was observed in all sites, with a range of 702-2119 kg/ha (mean response=1228 kg/ha). As a general trend, no significant source effects on S response were detected. Thus, in most sites S fertilizer effectiveness was not significatively affected by sulphur form or water solubility. However, in few sites, better behavior of S as sulphate was found. There was not S rate effect, and lower rate of S (10 or 15 kg/ha) was enough to provideS for the levels of yields obtained in present experiments.