The influence of subterranean clover pastrues on soil fertility. I. Short-term effects

Abstract

Under a subterranean clover pasture on a light-textured soil at Kojonup, Western Australia, soil nitrogen accumulated at a fairly steady rate of 42 lb/acre/year over a 5 year period. The increase in soil nitrogen accounted for differences in wheat production following the clover ley whether measured as total dry weight, yield of grain, or uptake of nitrogen. The clover treatments had little effect on the percentage of nitrogen in the grain or on the baking quality of the flour. Each additional year of clover gave an additional yield of 120 lb of wheat grain per acre for the first crop. Yields for second crops were considerably lower than the first but residual effects were evident. A practical implication of the results is that short leys of 1 to 2 years' duration followed by a single cereal crop could be a suitable cropping practice for the Kojonup area.

Effects of perennial (‘Russell’) lupins on soil nitrogen and carbon in acid high-country soils

“…The same trend also demonstrated for mean soil mineralisable N that was higher where the lupin stand was older. The lupin soils had higher total soil N (%) than those under pasture at both depths, supporting the findings of Watson (1963) (subterranean clover) and Vallis (1972) (clover/grass mixes). These results provide some evidence of soil N accumulation with increasing age of the lupin stand.…”

The Influence of Lime, Lime Pelleting, and Method of Sowing on the Nodulation and Growth of Subterranean Clover

“…N fixation, in terms of N harvested in the herbage, was of the order of 150 Ib/ac. This does not account for any increase in soil N. Watson (9) suggests that for every 100 Ib N/ac harvested in the leaves of subterranean clover there is an increase in soil N of 60 Ib/ac. He reports an increase of soil N of 40 lb/ac/yr.…”

Evaluation of the nitrogen contribution of legumes to subsequent cereals

“…The beneficial residual effects of legume cultivation on the yield of subsequent crops has been demonstrated in many studies (Nambiar et al 1982;Bandyopadhyay & De 1986;Senaratne & Hardarson 1988). This residual effect was noted when the legumes were incorporated as green manure (Heichel 1987), grazed by animals (Watson 1963), harvested for hay (Papastylianou 1987;Papastylianou & Samios 1987) or for grain (Blumenthal et al 1988). Thus, the beneficial residual effect is not necessarily dependent on above-ground material being returned to the soil, although the magnitude of yield increase of the subsequent crop is related to the amount of material returned to the soil (Heichel 1987).…”