Responses of three legumes to lime in several acid soils of São Paulo

Abstract

The responses of Medicago sativa, Phaseolus atropurpureus and Stylosanthes gracilis to lime applications to four latosols and four red-yellow podzols of the State of São Paulo were measured in a greenhouse trial. Alfalfa responded to lime in the pH range of 4.5 to 6.0 with maximum yields at 6.4 or above in all soils. In only one soil, liming to pH values above the maximum caused a decreased yield of alfalfa. Applications of Mn to two soils decreased yield of alfalfa only at pH values of less than 5.5. The average maximum yield of Phaseolus for all soils was at a pH of 6.1, and for Stylosanthes the average maximum yield was at pH 6.4. The average responses to lime in the pH range from 4.5 to 6.0 were 93% and 146% for Phaseolus and Stylosanthes respectively. Both of these tropical legumes reduced yields as the pH increased above the region of 6.2 to 6.4. However, Phaseolus and Stylosanthes yields greatly increased in some soils and were unchanged or reduced in others. A significant interaction between soils, legumes and Mn treatments was found.