【摘要】 通过田间定位试验、室内培育试验以及一系列物理、化学性质的测定 ,探讨了秸杆直接还田、堆沤还田和过腹还田等有机物质对改良淮北低产土壤—砂姜黑土的效果及机理。结果表明 ,增施有机物料能增加土壤孔隙度 ,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 ,提供多种有效养分 ,培肥土壤 ,并最后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需的活性有机胶体 ,以及其有机酸能溶解土中原有的 Ca CO3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等。更多还原

【Abstract】 Through fixed field location experiment and greenhouse cultivation experiment, as well as a series of determinations of soil physical and chemical properties, the effect and mechanism that the different types organic substance ameliorated vertisol the middle low yield soil of Huaibei area have been explored The results indicate that organic substance of returning into soil can increase soil porosity, reduce soil bulk density,improve soil perviousness and properties of soil retention water and fertilizer, raise buffering power of soil, supply kinds of effective nutrient, and increase corn yield finally.The mechanism lies in not only the shear stress of montmorillonite has been cut down by humus, and its expansibility and shrinkage have been restrained, but also active organic colloid for forming organo mineral composite aggregate have been supplied. As well as its organic acid can dissolve CaCO 3 of soil and set free active Ca 2+ , the latter is bridge of forming composite aggregate, thereby, improve soil pedality etc.更多还原