Field Response of Four Tropical Legumes to Lime and Superphosphate1

Abstract

AbstractThe generalization is often made that tropical legumes show little or no response to lime, even in acid soils low in Ca. Phosphorus responses, however, are generally observed. The effect of lime in an acid, virgin spodosol (Oldsmar fs) in southern Florida plots was investigated. Significant yield responses to lime and P were observed. Maximum total annual dry matter production of centro (Centrosema pubescens Benth.), desmodium (Desmodium heterocarpon DC.), stylo (Stylosanthes guyanensis Swartz), and ‘Siratro’ (Macroptilium atropurpureum Urb.) required lime applications of about 2,200 kg/ha. Regression analyses suggested that centro and Siratro might respond to higher lime rates if combined with P rates higher than those used in the study. Calculated optimum P rates ranged from 45 to 78 kg/ha, with desmodium requiring the least. Liming beyond the optimum rate appeared to seriously reduce production of desmodium and stylo.