有机物料对砂姜黑土的改良效应及其机制

通过田间定位试验、温室培育试验和一系列物理、化学性质的测定 ,探讨了三种有机物料对淮北低产土壤—砂姜黑土的改良效果及机理。结果表明 ,有机物料回归土壤能增加土壤孔隙度 ,降低容重 ,改善土壤通透性和保水保肥性能 ,提高土壤的缓冲性。同时提供多种有效养分 ,培肥土壤 ,并表现为增加作物产量。其机理不仅在于所提供的腐殖质能降低砂姜黑土中含量过高的蒙脱石矿物的剪切应力 ,抑制其胀缩性 ,而且还在于它们能提供形成有机无机复合团聚体所必须的活性有机胶体 ,以及其有机酸能溶解土中原有的CaCO3成为活性的Ca2 离子 ,后者是形成复合团聚体的桥梁 ,从而改善了土壤的结构性能等。

AMELIORATIVE EFFECT AND MECHANISM OF ORGANIC MATERIALS ON VERTISOL

Through field fixed location experiment and greenhouse incubation experiment, as well as a series of determinations of soil physical and chemical properties, the ameliorative effect and mechanism of three kinds of organic material on vertisol -the middle-low yield soil of Huaibei area have been explored. The results indicated that returning organic material to soil can increase soil porosity, reduce soil bulk density, improve soil perviousness and soil retention of water and fertilizer, raise soil buffer capacity, supply multi-nutrients, and increase crops yields. The mechanism involved not only the reduction of shear stress of montmorillonite was reduced by humus, and restraint of its expansibility and shrinkage, but also supplying active organic colloid to form organo-mineral composite aggregate. In addition, organic acid can dissolve CaCO 3 in soil and release active Ca 2 , which formed the bridge of composite aggregate, thereby, improved soil pedality etc.