Effect of Soil pH and Related Acidity Factors on Yields of Sweetpotatoes and Soybeans Grown on Typical Soils of the Humid Tropics

Abstract

The effects of soil pH and related acidity factors on the yields of sweetpotatoes, Miguela var., and soybeans, Jupiter var., were determined on typical Oxisols and Ultisols of Puerto Rico. The study revealed no significant effect of pH and acidity factors on the yield of the sweetpotato variety, which was quite tolerant to high soil acidity and exchangeable Al. Yields were similar to those obtained by other researchers who worked with other varieties. Soybeans, although relatively tolerant to high levels of exchangeable Al, were adversely affected when values surpassed 5.5 meq/100 g of soil in a clayey Ultisol. Exchangeable base content was directly related to soybean yield grown on a light textured Oxisol. Yields obtained are considered excellent. Highly significant correlations between soybean leaf N content and yield was found in the clayey Ultisol.