Responses of four perennial pasture legumes to soil amendment with lime and superphosphate.

Reports the results of a study conducted to estimate the effect of differential lime and phosphate application on yields of crownvetch, lucerne, white clover and Kenya white clover. Measures also the effects of the treatments on soil acidity, the content of various nutrient elements in the soil and the calcium and phosphorus content of the herbage; Yield response of crownvetch (Coronilla varia) cv. Penngift, lucerne (Medicago sativa) cv. CUF 101, white clover (Trifolium repens) Dusi type and Kenya white clover (T. semipilosum) cv. Safari to differential application of lime and superphosphate were determined in a 5 x 4 factorial experiment on a virgin soil of the Griffin form. Lime rates varied from 0 to 7t/ha and phosphate rates from 0 to 150kg P/ha. Patterns of response differed markedly between legumes. Clover yields were high even in the absence of lime and responses to differential lime rates were negligible. By contrast, yields of crownvetch and lucerne where no lime was applied were very low and yields increased markedly with successive increments of lime, the response of lucerne being greater than that of crownvetch. All the legumes responded to the application of phosphate, but yields increases decreased progressively with increasing phosphate level. Effects of the treatments on soil acidity and extractable nutrient elements were determined. A notable feature was an interactive effect between lime and phosphate on extractable phosphorus (0, 25M NaHCO3, pH 8,5). Values increased progressively with successive increments of phosphate application, but decreased with increasing lime application. Depressive effects of lime were greater than at the lower levels of phosphate.Keywords: Calcium; Coronilla varia; Crownvetch, Lucerne; dry matter yield; ermelo district; Fertilization; Kenya white clover; Legumes; Lime; lucerne; Medicago sativa; nooitgedacht research station; Nutrients; pasture; Pastures; Perennial pasture legumes; ph; phosphate; Phosphorus; Soil acidity; Soil amendment; south africa; Superphosphate; treatments; Trifolium repens; Trifolium semipilosum; White clover; YieldJournal of the Grassland Society of Southern Africa