Managment of sulphur fertilizer in forage sorghum crop cultivated in eutrophic Cambisol with alkaline pH

Abstract

The objective of this study was to analyze the effect of soil fertilization with sulfur-based fertilizers, sulfate and elemental sulfur forms on biomass production, nutrient characteristics of sorghum and soil chemical properties. The experiment was carried out in a 4 x 4 factorial scheme (four sulfur sources: single superphosphate, agricultural gypsum, elemental sulfur powder and elemental sulfur granulated with bentonite, and four sulfur doses: 0, 40, 80, 120 mgdm-3) using four replications in a completely randomized design, being cultivated in pots under greenhouse conditions. The sorghum was cultivated for a period of 51 days after emergence of the seedlings. The shoot dry mass, shoot macronutrients content, root and soil and pH of the soil were evaluated. There were interactions between sources and sulfur doses in the variables such as shoot dry mass, sulfur in the root, sulfur and calcium in the soil. Elemental sulfur (granulate) showed lower concentrations of phosphorus, sulfur and N:S ratio in the shoot. The concentrations of potassium, calcium and magnesium did not show significant differences, both for the shoot and the root. The pH of the soil was reduced depending on the sources and doses of elemental sulfur. The sources and doses of sulfur did not influence the levels of phosphorus, potassium, and magnesium in the soil. The elemental sulfur in the form of powder is the best source of sulfur for forage sorghum cultivated in soil with alkaline pH.