The effect of a fertilizer element on its concentration in grass/ legume herbage depends mainly on (1) quantity applied, (2) the degree of deficiency, (3) whether the added nutrient is "fixed" or leached and, (4) whether the fertilizer changes the proportion of clover to grass. Fertilizers increase concentrations of major elements in herbage much more in the deficiency range than when levels are already high. However, plants appear to lack the ability to restrict intake of the trace elements. In a stocking rate x lime trial, in which lime increased pasture yields, lime responses in animal production were found only at the high stocking rate, indicating a feed quantity, rather than quality effect. This was confirmed by plant analysis.
