Temperature, Soil Moisture, and Antecedent Sulfur Application Effects on Recovery of Elemental Sulfur as SO4‐S in Incubated Soils

Abstract

The oxidation of elemental sulfur (S) to plant‐available SO4‐S is influenced by several factors. Experiments were conducted to compare the recovery of applied elemental S as SO4‐S in Dark Gray Chernozem (Boralfic Boroll), Black Chernozem (Udic Boroll), and Gray Luvisol (Boralfs) soils incubated at different temperature, moisture, and antecedent elemental S application conditions. For all soils and incubation periods, the recovery of SO4‐S increased with temperature from 6 to 36°C and with soil moisture from 40 to 90% field capacity (FC). At low temperature and soil moisture, the recovery of SO4‐S increased relatively steadily with incubation time up to 30 days, but at optimum temperature and soil moisture, the SO4‐S recovery was relatively faster at the start of the incubation and declined as incubation progressed. Previous addition of elemental S to soil accelerated the SO4‐S recovery. The rate of SO4‐S recovery was also influenced by soil type. The findings suggest that the amount of elemental S fertilizer needed to meet the crop requirements should be adjusted based on temperature, soil moisture, previous elemental S application history, and soil type.