Mineral element concentrations of sorghum genotypes grown on tropical acid soil

Abstract

Sorghum [Sorghum bicoior (L.) Moench] genotypes show large differences in dry matter and yield when grown on many tropical acid soils. The objective of this study was to determine differences in mineral element concentrations in sorghum genotypes grown on an acid oxisol limed with 2 and 6 Mg dolomitic limestone ha^‐1 in Colombia, South America. Fifty genotypes showed differences in dry matter yield and concentrations of P, K, Ca, Mg, S, Si, Al, Mn, Cu, and Zn. Liming did not change low, high, and mean leaf concentrations of P, K, Mg, S, and Cu for the genotypes. Concentrations of Al, Mn, and Fe in the genotypes were higher in leaves of plants grown at 2 (pH 4.5 and 62% AT saturation) than at 6 Mg lime ha^‐1 (pH 4.8 and 34% Al saturation). At the 6 Mg ha^‐1 lime rate, leaf concentrations of Ca and Si increased. Silicon may have reduced the effects of toxic Al, and possibly toxic Fe. Genotypes showed sufficient variability in mineral element concentrations that selection for improved values of these traits appears feasible.

Key words:

• Acid soil tolerance
• Al toxicity
• Mineral nutrition
• Mineral stress
• Plant breeding
• Sorghum bicoior

Notes

Published as Paper No. 8362, Journal Series, Nebraska Agricultural Research Division, Lincoln, from Projects NE‐114 (Nebraska) and MS‐104 (Mississippi). Supported in part by the International Sorghum/Millet Collaborative Research Support Program (INTSORMIL CRSP) through U.S. Agency for International Development (USAID) grant AID/DAN‐1254‐G‐55–5565–00.