Effect of Waterlogging and Organic Matter on the Loss of Applied Sulfur

Abstract

AbstractGypsum and elemental S (56 kg/ha) were applied to lysimeters before the first fall rains. Waterlogging and barley straw (Hordeum vulgare L.) (11,200 kg/ha) were additional variables imposed in all possible combinations. Nitrogen was applied uniformly to all tanks, and cereal and grass were grown during two seasons. In the first year after application of gypsum, 45 and 41 kg/ha S were recovered in the leachate from freely drained soil with and without straw, respectively. The free draining tanks treated with elemental S gave values of 10 and 7 kg/ha S recovered in the leachate for the straw and no straw treatments. Waterlogging decreased leaching loss of sulfur by an average of 40%. Oats (Avena sativa L.) planted when waterlogging was discontinued took up more S in the absence of straw and also more S was leached than on the freely drained treatment. However, no significant increase in uptake occurred in the succeeding grass crop as a result of the sulfur conserved by the waterlogging. It is concluded that where waterlogging occurs during the winter months in annual‐type range soils, SO4‐S leached from either applied or natural sources of sulfur is likely to be decreased, but also that sulfur conservation by this means is unlikely to aid the production of grasslands in California.