ABSTRACT

Nutrient deficiencies in calcareous soils are mostly related to high soil pH whereas sulfur supplement could facilitate nutrient element uptake by the crop plants. However, inefficient sulfur oxidation in soils is a limiting factor for this response. Mixing elemental sulfur with bentonite mineral can increase oxidation of sulfur since bentonite provides the sulfur particles with a better dispersion condition following absorption of water. Purpose of this study is to evaluate the efficiency of sulfur-bentonite granules with various proportions of bentonite to improve nutrient element uptake by the crop plants cultivated in calcareous soil. Four treatments of the sulfur-bentonite granules having 10, 20, 30 and 40 percentages of bentonite compared to the controls with no granules were applied to maize crop plants (Zea mays L.) cultivated in pots filled with an inoculated calcareous soil using Thiobacillus thioparus. At the end of the 80 days growth period; the results revealed significant soil pH decrease and growth parameters improvement with increasing bentonite proportion of the granules among the treated pots. Anyway, it appeared that a bentonite proportion of more than 30% in the granules can reverse improving trend of growth parameters in the cultivated plant. It was also confirmed that efficiency of the sulfur-bentonite granules is mostly contributed to increasing uptake of micro-nutrients of iron, manganese and copper alongside macro-nutrients of sulfur and phosphorus by the crop plants cultivated in the studied calcareous soil.

摘要

钙质土壤中的营养缺乏主要与高土壤 pH 值有关，而硫磺补充可以促进作物对营养元素的吸收。然而，土壤中低效的硫氧化是这种反应的限制因素。将元素硫与膨润土矿物混合可以增加硫的氧化，因为膨润土在吸水后为硫颗粒提供了更好的分散条件。本研究的目的是评估含不同比例膨润土的硫磺膨润土颗粒对提高钙质土壤中栽培作物对营养元素吸收的效率。与没有颗粒的对照相比，具有 10、20、30 和 40% 膨润土的硫膨润土颗粒的四种处理被施用于玉米作物植物 ( Zea maysL.) 在填充有接种钙质土壤的盆中使用硫杆菌硫杆菌培养。80天生长期结束时；结果表明，随着处理过的盆中膨润土颗粒比例的增加，土壤 pH 值显着降低，生长参数得到改善。无论如何，颗粒中超过30%的膨润土比例似乎可以逆转栽培植物生长参数的改善趋势。还证实硫膨润土颗粒的效率主要有助于增加在研究的钙质土壤中种植的作物对铁、锰和铜的微量营养素以及硫和磷的大量营养素的吸收。