不同利用方式对紫色土理化性质的影响

以三峡库区紫色土为对象,研究了稻田、果园、菜田和人工林地等4种不同土地利用方式对土壤理化性质及土壤总团聚体和水稳性团聚体的影响。结果表明,稻田土壤的土壤容重最低、孔隙度最大、田间持水量最大;而林地土壤的孔隙性和持水性最差。>0.25mm总团聚体以菜田最高,稻田最低;>0.25mm水稳性团聚体数量表现为:菜田>林地=稻田>果园(P<0.05);稻田土壤pH值、有机质和全氮含量最高,明显高于果园、菜田和人工林地,稻田土壤碱解氮含量明显高于果园和人工林地(P<0.05),土壤全磷、有效磷和速效钾含量以果园最高,林地最低。

Effects of Different Land--use on Purple Soil Physical and Chemical Properties

Soil physical and chemical properties under different land--use patterns （paddy field, orchard, vegetable field and artificial woodland） in purple soil of Three Gorges Reservoir Area were studied in this paper. The results showed that pad- dy field had the lowest bulk density, the greatest porosity and field capacity~ under the condition of dry sieve, vegetable field had the greatest 〉0.25ram soil aggregates and paddy field had the least; under the condition of wet sieve, the amount of 〉0. 25ram soil aggregates showed as vegetable field 〉 artificial woodland = paddy field 〉 orchard （P〈0.05）. Soil pH, organic matter and total N of paddy field was significantly higher than orchard soil, vegatable soil and artificial woodland soil; and soil alkali--hydrolyzable N of paddy field was significantly higher than orchard soil and artificial woodland soil （P〈0.05）. soil total P, available P and available K of orchard soil was the highest among these four land--use patterns.