有机物料在白土中的分解与转化

三年田间试验结果表明,在等氮量条件下,有机肥与无机肥配合施用的各处理的土壤有机质含量显著高于无机氮处理。砂滤管试验的结果表明,供试有机物料的腐殖化系数为0.13～0.57;有机物料能显著增加土壤有机碳和重组有机碳含量,促进土壤有机-无机复合体的形成,提高土壤增值复合量和增值复合度,改善腐殖质结合形态,使松结态组分增加,紧结态组分减少,土壤腐殖质得到活化。结果还表明,供试白土有机质的年矿化量约为145kg/亩,由作物根茬形成的土壤有机质约为105kg/亩,每年每亩施1600kg厩肥或300kg干稻草方能保持土壤碳素的平衡。

DECOMPOSITION AND TRANSFORMATION OF ORGANIC MATERIALS IN BLEACHING PADDY SOIL

The experiments were carried out under field condition of rice-wheat rotation in Yixing County, Jiangsu Province. The results obtained indicated that the humification coefficients of the organic materials in soils were in the range of 0.13 to 0.57. The application of organic materials to the soil increased the contents of organic carbon in both soil and its heavy fraction, promoting the formation of soil organo-mineral complexes, thus increasing additional complexing quantity and additional complexing degree. It was also found that when closely combined humus reduced, loosely combined humus was increased, and the humus was activated during the transformation of organic materials. The decomposition amount of organic matter in studied soil was approximately 2175kg/ha, y, while the amount of soil organic matter contributed by crop residues was approximately 1575kg/ha, y. In order to maintain the balance of organic matter in soil, it is necessary to apply at least 24t/ha of farmyard manure or 4.5t/ha of dry rice straw every year.