The value of liquid digested sewage sludge. I. The effect of liquid sewage sludge on growth and composition of grass-clover swards in South-east England

Abstract

During the period 1959-62 liquid digested sludge was applied to grass to supply nitrogen at rates similar to those normally recommended to farmers. The responses were compared to those produced by equivalent inorganic fertilizers.Liquid digested sludge gave as large an increase in dry matter as equivalent fertilizers. At the low rate of application the mean dry matter increase was 15.2 lb./lb. of applied nitrogen, and at the high rate the mean response was 11.0 lb. dry matter per lb. of nitrogen.On one site, all treatments reduced the clover percentage, the high rate more than the low rate. Sludge treatments reduced the clover percentages less than equivalent inorganic fertilizers.