RESPONSE OF DETERMINATE SOYBEAN CULTIVARS TO LOW PH SOILS

The main purpose of this study was to identify soybean cultivars which maintained high yields on acid soil. A secondary purpose was to determine what nutrient changes were responsibe for the yield losses occurring due to low pH soil. The significant cultivar x lime interaction indicated that yield in some cultivars was more adversely affected than in others. Terra Vig 708 and Deltapine 345 showed no significant yield loss when grown on low pH compared to limed soil and were classified as very insensitive to soil acidity. Other cultivars were classified as either moderately insensitive, sensitive, very sensitive, or severely sensitive. Analysis of variance and correlation studies indicated that the most probable reason for reduced seed yield on low pH compared to limed soil in this study was interference with N fixation and reduced N uptake by the plants grown on low pH soil.