碱性材料对修复与改良酸性硫酸盐土壤障碍因子的研究

摘要

Pot experiment was conducted to study the effects of different basic materials (lime, self-development ameliorant and calcium magnesium phosphorus treatment) on the restoration of the main limiting factors and rice growth in acid sulfate soils (ASS). The results showed that the effects of different basic materials were significantly different on soil physical and chemical characteristics, availability of soil nutrient and rice growth. Compared with NPK, SAM and CMP1 treatments effectively increase pH values by 1.25 and 0.92 units respectively, increased available P content by 3.1 times and 2.6 times respectively, while reduced greatly the contents of available Fe and Mn, exchangeable H+ and Al3+. SAM and CMP1 treatments extremely improved root surroundings thereby effectively control the transport of Fe, Mn and Al elements to the ground through ensuring of enough available P content in combination with the supplement of elements such as Ca, Mg and so on. SAM and CMP1 treatments promoted the growth and development of root, significantly increased the root activity at peak tillering and heading stages, and significantly increased rice grain yield by 121.1% and 105.1% in comparison to NPK, respectively. The effect of LIME treatment was next to SAM and CMP1 treatments. In conclusion, it was preliminarily consider that the key points of the alleviation mechanism of basic materials on limiting factors in ASS lies in improving the available contents of nutrient elements and pH, reducing the contents of some toxic metal elements. In the conditions of this study, CMP1 plays an extremely important role in restoring the limiting factors of ASS, but its cost was 3 times higher than SAM. Thus, taking the applicability for a long time and cost of soil ameliorant into consideration, self-development ameliorant should be a more appropriate soil conditioner for ASS.%采用盆栽试验研究了不同碱性材料(石灰、自研改良剂、钙镁磷肥)对酸性硫酸盐土壤主要障碍因子的修复及其对水稻生长的影响。结果表明，不同碱性材料对土壤理化特性、土壤养分有效性和水稻生长的影响存在明显差异。与常规施肥(NPK)处理相比，自研改良剂(SAM)和钙镁磷肥(CMP1)处理土壤pH增加了1.25和0.92个单位，土壤速效磷含量分别增加了3.1倍和2.6倍，土壤有效铁、有效锰、交换性H+、Al3+含量均大幅下降。SAM与CMP1处理通过提供足够的有效磷并补充钙、镁等元素，有效改善了根系生长环境，从而有效控制铁、锰、铝等元素向地上部转运，进而对作物的生长起到促进作用。SAM和CMP1处理较NPK处理有效促进了关键生育期水稻根系活力并显著增加了水稻籽粒产量，增幅分别达121.1%和105.1%。石灰效果次之。综上，初步认为碱性材料改良酸性硫酸盐土壤的关键在于保证了充足有效磷的同时，提高了土壤 pH，降低了土壤金属的毒害。本试验条件下，钙镁磷肥对修复和改良酸性硫酸盐土壤障碍因子效果非常明显，但其成本是自研改良剂的3倍，因此，基于改良剂的成本与长期适用性考虑，自研改良剂可能是该类土壤改良的最佳选择。