ABSTRACT

Soil acidity is one of the most limiting factors in crop yield. We evaluated the effect of soil acidity correction with magnesium limestone and calcium (Ca) and magnesium (Mg) silicate associated gypsum application, on the growth of a forage grass. The experiment was conducted in a greenhouse with a soil sample from B horizon of a Rhodic Hapludox. The experimental, design was completely randomized blocks with seven treatments each replicated four times. Two sources of amendments (magnesium limestone and calcium and magnesium silicate) were incorporated in a surface (0 to 0.20 m) soil sample using three application methods: amendment without gypsum, amendment with gypsum incorporated in the sample, amendment with superficial application of gypsum, and a control treatment without amendment and gypsum. The limestone and silicate were effective in correcting acidity and increasing exchangeable soil bases in the 0.20 m layer. The use of acidity correctors combined with gypsum, mainly incorporated, neutralized toxic aluminum and increased the levels of sulfate and Ca in depth and the concentrations of Ca, Mg, nitrogen and phosphorus in dry weight of the shoot (DWS). The silicate increased the concentrations of silicon (Si) the soil up to 0.20 m depth and Si concentration in the plant. The silicate with gypsum provided greater production of DWS, while limestone with gypsum increased the production of dry weight of roots the plant. The application of silicate in complement to limestone, combined with incorporated gypsum is the most suitable method for soil correction in the implantation of mombaça grass.

摘要

土壤酸度是作物产量的最大限制因素之一。我们评估了使用石灰石镁和硅酸钙 (Ca) 和硅酸镁 (Mg) 相关的石膏对土壤酸度校正对牧草生长的影响。实验在温室中进行，土壤样品来自 Rhodic Hapludox 的 B 层。实验设计是完全随机的区组，有七个处理，每个处理重复四次。使用三种施用方法将两种改良剂（石灰石镁和硅酸钙镁）掺入表面（0 至 0.20 m）土壤样品中：不含石膏的改良剂、样品中掺入石膏的改良剂、表面施用石膏的改良剂、和不加修饰和石膏的对照处理。石灰石和硅酸盐在 0.20 m 层有效地纠正酸度和增加可交换土壤碱度。酸度校正剂与石膏结合使用，主要掺入、中和有毒铝并增加深度硫酸盐和钙的含量以及芽干重 (DWS) 中钙、镁、氮和磷的浓度。硅酸盐将土壤中的硅 (Si) 浓度增加到 0.20 m 深度，并增加了植物中的硅浓度。含石膏的硅酸盐提供了更高的 DWS 产量，而含石膏的石灰石增加了植物根干重的产量。硅酸盐与石灰石的补充应用，结合掺入的石膏是最适合种植蒙巴萨草的土壤矫正方法。