EFFECT OF PHOSPHORUS AND SULPHUR FERTILIZATION ON THE NUTRITIVE VALUE OF SUBTERRANEAN CLOVER (TRIFOLIUM SUBTERRANEUM)

Abstract

Phosphorus or sulphur applied alone to a soil deficient in P and S did not increase subterranean clover (Trifolium subterraneum) yields; but when the two elements were applied together, a five-fold ,increase was obtained. The nutritive value of the clover was evaluated by measuring sheep rumen microbial activity using an anaerobic manometric technique. Subterranean clover fertilized with P alone increased the microbial activity about 6%. In contrast, the clover fertilized with S alone decreased activity about 5%. When P and S were applied together, microbial activity was increased 20 to 30%, depending on the rates applied. There was a positive correlation between the level of reducing sugars in the clover and the degree of rumen microbial activity.