Dry matter yield of common bean, lowland rice, corn, soybean, and wheat at different basic cation saturation ratios in acid soil

Abstract

Soil acidity is an important yield limiting constraint in crop production in various parts of the world, including Brazil. Five greenhouse experiments were conducted to evaluate responses of common bean (Phaseolus vulgaris L.), lowland rice (Oryza sativa L.), corn (Zea mays L.), soybean (Glycine max L. Merr.), and wheat (Triticum aestivum L.) to different basic cation saturation ratios on an Inceptisol. The mean soil basic cation saturation ratios at harvest of each crop typically ranged from 49 to 98%, depending on the rate of CaCO3 applied. Dry matter yield (DMY) of shoots, roots and root length of all the crops tested was significantly affected by basic cation saturation ratio. The optimum basic cation saturation ratio for maximum DMY of shoots was 56% for rice, 74% for common bean, 66% for corn, 69% for soybean, and 88% for wheat. The optimum basic cation saturation levels for root dry weight varied from 48 to 72%, depending on crop species. Similarly, optimum cation saturation for root length varied from 59 to 80%. Adequate levels of calcium (Ca), magnesium (Mg), and potassium (K) saturation, Ca/Mg ratio, Ca/K ratio, and Mg/K ratio also varied among crop species. This shows that crops responded differently to soil acidity. Among the crops tested, rice was the most tolerant and wheat was the most intolerant to soil acidity.