Abstract
Yield response of three plant species to liming was determined in pot tests using soils typical of the humid upland region of Puerto Rico and of the southeastern United States. Three general response patterns were observed, but they were not clearly related to either crop species or soil category: 1) Increasing yield with increasing soil pH to a maximum between 5 and 6, followed by little or no change at higher pH values; 2) no clear response; and 3) increasing yield with increasing pH to a maximum between 5 and 6, followed by a decrease at higher pH values. These results support the concept that satisfactory plant growth can be made on acid soils of tropical regions at somewhat lower pH levels than on soils of temperate regions. They also suggest that liming experience gained in temperate zones could be used with caution for acid soils of tropical regions.