The influence of lime and phosphorus on the growth of white clover on highly weathered Natal soils

Abstract

Results of field studies conducted on highly weathered Natal soils in which the performance of white clover (Trifolium repens cv. Regal ladino) was examined under a range of lime and P treatments applied in factorial combination, are presented. Despite adverse moisture conditions over the three seasons during which the studies were in progress, highly significant yield responses to lime and P were noted. Up to 460 kg P ha⁻¹ were required in order to obtain a levelling-off of dry matter response to P. This large P requirement was consistent with information obtained from P sorption isotherms indicating extremely high P fixation in the soils under study. A noteworthy feature of P response data was a suggestion of increased P requirement under conditions of low rainfall. Yield responses to lime were commensurate with the elimination of exchangeable Al.