Variations in magnesium concentration in the pasture herbage result from changes in the species composition during grazing season. High content of Lolium perennein the sward can decrease and Dactylis glornerata can increase magnesium concentration in the pasture fodder.
From this experiment there is no evidence that low doses of nitrogen are harmful to the mineral balance of pasture herbage. More care should be taken to potassium application, particularly where available soil potassium is high.