重庆合川区坡耕地退耕还林后改土效应研究

Research on Sloping Cropland Soil Improvement Effects After Returning Farmland to Forest in Hechuan District of Chongqing

退耕还林是退化生态系统重建的重要途径。为了探讨不同退耕还林模式下的土壤理化性质的演变规律,以重庆合川区退耕还林地为研究对象,对7种不同退耕还林模式坡耕地的土壤理化性状进行对比分析。结果表明:坡耕地退耕还林后,土壤理化性质有很大改善,土壤总孔隙度、毛管孔隙度与粘粒含量均表现为退耕地>坡耕地;土壤养分中,除速效磷元素和速效钾之外,土壤平均有机质、全氮、速效氮、全钾均表现为退耕地>坡耕地。不同类型的退耕林地土壤质量恢复具有明显差异,其中花椒土壤有机质和氮元素含量,栾树土壤磷元素含量,水杉土壤钾元素含量分别最高。

Converting cultivated land into forestland is an important way for the reconstruction of degraded ecosystem. To investigate the evolution of the soil under different models of returning farmland to forest, the physiochemical properties of soil taken from several forestry lands under 7 different models of returning farmland to forest in Hechuan District in Chongqing was compared. The results showed that the physiochemical properties of the soil were greatly improved. For the total soil porosity, capillary soil porosity and clay content, those of the reforestation fields were larger than those of the slope fields. Expect of available P and K, all of the soil nutrient was enhanced after the reforestation. The quality of recovering for the soil differed with different styles of reforestation qualitatively. The soil organic matter and N in the soil reforested by Chinese prickly ash, P in the soil reforested by Paniculed goldraintree, K in the soil reforested by Metasequoia obtained the maximum respectively.