城市土壤质量演变与有机改土培肥作用研究

Study on Quality Evolution of City Soil and Effect of Soil Amelioration by Organic Fertilizer Application

采用对比分析的方法 ,研究了从自然土壤到森林土壤和农业土壤 ,最终演变为城市土壤的过程中 ,土壤质量的变化及其成因以及有机改土培肥措施对城市土壤质量有效性的影响。结果表明 :城市土壤演变过程中土壤物理性质和养分含量发生了明显的变化。原始未受人为影响的五花草甸自然土壤的容重最小 ,农业老耕地土壤其次 ,森林土壤再次 ,城市土壤最大。城市绿化用地 2 0～ 4 0 cm土壤容重分别比森林土壤和农业土壤提高 17.7%～4 3.7%和 35 .4 %～ 93.9% ,总孔隙度降低 1.9%～ 13.0 %和 34.1%～ 5 2 .4 % ,土壤饱和持水量分别降低 16 .6 %～ 39.5 %和 6 0 .0 %。城市土壤的草坪用地和绿化用地 ,表层土壤有机质比森林土壤降低 82 .0 %～ 95 .9%和77.1%～ 94 .8% ;比农业老耕地土壤降低 86 .6 %和 82 .9% ;比自然土壤降低 96 .1%和 95 .0 %。 0～ 6 0 cm土层城市土壤全氮、速效氮降低 ;全磷和有效磷均比森林土壤提高 70 .1%～ 117.4 %和 173.5 %～ 2 2 2 .1% ,比农业土壤提高 4 4 .9%～ 16 1.2 %和 98.4 %～ 6 94 .4 % ,磷在城市土壤中富营养化现象严重。在土壤演变过程中 0～ 6 0 cm土层 p H值没有明显变化。城市土壤增施有机肥可降低土壤容重 ,改善土壤通气状况 ,提高土壤水分以及调节和改善土壤 p H值 ,使土壤?

By method of comparison and analysis, the evolution process of soil quality and its evolution reason from natural soil to agricutural soil and city soil, as well as the effect of organic fertilizer application on the availability of soil quality were studied. The results showed: There were apparent changes of physical properties and nutrition content in the evolution process of city soil quality. The volumetric weight of natural soil(tessellated meadow soil) without the influence of human activities was the lowest, that of old plough land for agriculture was lower, that of forest soil was low, that of city soil was highest in four different types of soils. That at the depth of 20~40cm soil layer for city planting land was increased by 17.7%~43.7% and 35.4%~93.9%,the total porosity was decreased by 1.9%~13.0% and 34.1%~52.4%,saturation capacity was decreased by 16.6%~39.5% and 60% respectively, in comparison with that of forest soil and agriculture soil. The organic matter on the surface soil of city lawn land and city planting land was decreased by 86.6% and 82.9% as compared with old plough land for agriculture, decreased by 96.1% and 95.0% in comparison with natural soil. The total nitrogen and rapidly available nitrogen of city soil at the depth of 0~60cm soil layer was decreased. The total phosphorus and available phosphorus were increased by 70.1%~117.4% and 173.5%~222.1% as compared with that of forest soil, 44.9 %~161.2% and increased by 98.4%~694.4% in comparison with agricultural soil. This result showed that there was apparent ultrophication of phosphorus in city soil. There was not apparent change of pH value within the depth of 0~60cm soil layer in the process of soil evolution. Fertilization for city soil can reduce volumetric weight of the soil, improve soil air conductivity, raise soil water content, regulate and improve pH value to make the soil neutralism. Meanwhile, organic matter, total nitrogen, available nitrogen, total phosphorus and available phosphorus were improved.