ABSTRACT
Summary Liming has been declared unnecessary for tropical legume production because tropical legumes (1) are efficient in extracting Ca from soils and are tolerant of excess Al, Fe, and Mn, and (2) are readily nodulated by alkali-producing Rhizobium that can function in acid soils. Numerous research reports from Australia, Uganda, Brazil, and Colombia lend credence to this thinking, since no lime responses were observed in those studies. In other work, liming actually depressed tropical legume growth. However, positive responses have been reported in Australia, Hawaii, and Brazil. In Florida, we have observed considerable improvement in the production of Siratro (Macroptilium atropurpureum Urb.), Desmodium heterocarpon DC., Stylosanthes guianensis Swartz., Centrosema pubescens Benth., and Aeschynomene americana L. with increasing lime rates up to 2,000-3,000 kg/ha in pot studies, plot studies, and in commercial pastures. Perhaps tropical legume production could be increased in other regions through a combination of liming, correcting nutrient deficiencies, and inoculating with Rhizobium adapted to moderate soil pH. At least there now is sufficient evidence to suggest that lime responses should be evaluated when tropical legumes are being introduced into new areas.
