Sulphur concentration of soils and plants and its requirement for ruminants in the Inner Mongolia steppe of China

Abstract

The sulphur status of four soils and 122 forage plants from the Inner Mongolia steppe was determined. The organic sulphur concentration ranged from 17 μg g –1 in the 0·2–0·4 m soil layer to 397 μg g –1 in the topsoil. The mean sulphate‐S concentrations were <10 μg g –1 ; greater concentrations were found only in the chernozem soil. Biomass‐S accounted for 0·018–0·028 of total S in four soils. Three‐quarters of plant samples examined had <1·6 g kg –1 S, and >0·80 of them had an N:S ratio >14:1. More than 0·80 of the plants were deficient in S. There was a close relationship between plant‐available soil sulphur concentrations and total plant sulphur concentrations. It was concluded that sulphur deficiency is widespread in the Inner Mongolia steppe and that sulphur fertilizer requirements should be evaluated.