Effect of cattle dung patches on soil tests and botanical and chemical composition of herbage

Abstract

Dung patches were applied in spring on a soil high in P and low in K. Under dung patches to below 7.6 cm depth, the increase in Truog P was rapid and sustained. A rise in exchangeable K and Na was rapid, reaching a peak 1½ months after dung application, but short-lived. Exchangeable Ca and Mg increased more slowly, reaching a peak after 4 months. In spite of its gradual release from dung, Mg moved to some depth; thus Mg could be leached under dung patches. Downward movement of faecal Ca was slight. Dung patches increased pasture yields in an area within 12.7 cm of the boundary of the dung patch for 3 months after application and again during the following spring. Total yield increase in this 12.7 cm wide band over 1½ years was approximately 50%. Ryegrass (Lolium perenne L.) growth increased in this area. Dung raised Mg concentration of herbage, particularly in clover. It depressed Na concentration of clover, and raised it in grasses after a short initial depression. A rapid and large increase in herbage K concentration aided a rapid apparent recovery of K applied in dung: recovery was 62% at 1½ months, 80% at 3½ months, and 93% at 14 months after dung was applied. Interactions of faecal nutrients are discussed