ABSTRACT

About 60 to 80% of the material extracted in vermiculite mining consists of unused waste, composed of minerals containing plant nutrients that can chemically improve the soil. The objective was to evaluate the potential of vermiculite mining residue associated with elemental sulfur in the chemical attributes of two alkaline saline soils. Two experiments were carried out in a completely randomized design in a 6 × 2 factorial scheme with four replications. In the first experiment, six doses of vermiculite waste enriched with 5% (50 g kg⁻¹) elemental sulfur (0, 10, 20, 30, 40 and 50 t ha⁻¹), and two alkaline soils (sodic soil and other non-sodic) were tested. In the second experiment, six doses of elemental sulfur (0; 0.25; 0.50; 0.75; 1.0; 1.25 g dm⁻³) and two soils (sodic soil and other non-sodic) were tested. At 30 and 105 days after soil incubation, the hydrogenionic potential (pH) values, electrical conductivity, concentrations of available sulfate (SO₄⁻²), phosphorus (P), and exchangeable calcium (Ca²⁺), potassium (K⁺) and sodium (Na⁺) were determined. The vermiculite waste associated with elemental sulfur can be used as an alternative source of K⁺ and contribute to reduce the pH of the alkaline soil and adding Ca²⁺ and SO₄⁻² to the soil. However, in soils with poor drainage, this compound should be used with caution due to the risk of soil sodification. Elemental sulfur only, reduced the pH and increased the levels of Ca²⁺ and SO₄⁻² in both studied soils and reduced levels of Na⁺ in sodic soil after 105 days of incubation.

摘要

蛭石开采中提取的材料中约有 60% 至 80% 由未使用的废物组成，这些废物由含有植物养分的矿物质组成，可以通过化学方式改善土壤。目的是评估与元素硫相关的蛭石矿渣在两种碱性盐渍土化学属性中的潜力。两个实验以完全随机设计进行，采用 6 × 2 因子方案，重复四次。在第一个实验中，六剂富含 5% (50 g kg ^-1 ) 元素硫（0、10、20、30、40 和 50 t ha ^-1）的蛭石废料和两种碱性土壤（钠质土壤和其他非钠）进行了测试。在第二个实验中，六剂量的元素硫（0；0.25；0.50；0.75；1.0；1.25 g dm ^-3) 和两种土壤（钠质土壤和其他非钠质土壤）进行了测试。在土壤孵化后 30 天和 105 天，氢离子电位 (pH) 值、电导率、有效硫酸盐 (SO ₄ ^-2 )、磷 (P) 和可交换钙 (Ca ²⁺ )、钾 (K ⁺ )的浓度和钠（Na ⁺）进行了测定。与元素硫相关的蛭石废料可用作 K ⁺的替代来源，有助于降低碱性土壤的 pH 值并添加 Ca ²⁺和 SO ₄ ^-2到土壤。但是，在排水不良的土壤中，由于存在土壤软化的风险，应谨慎使用该化合物。仅元素硫降低了研究土壤中的 pH 值并增加了 Ca ²⁺和 SO ₄ ^-2的水平，并在培养 105 天后降低了钠质土壤中的 Na ^+水平。