重庆合川区退耕还林地土壤改良效应研究  

Soil Improvement Effect of Returning Farmland to Forest in Hechuan District, Chongqing

作　　者：何艳[1] 孙保平[1] 肖恩邦 刘洋[1] 张建锋[1] 

机构地区：[1]北京林业大学水土保持学院,北京100083

出　　处：《土壤通报》2015年第6期1392-1398,共7页Chinese Journal of Soil Science

基　　金：国家林业局林业公益性行业科研专项经费项目(201004018)资助

摘　　要：本文以重庆合川区退耕还林地的7种不同林分林下土壤为对象,通过与对照玉米地不同深度的土壤理化性质进行比较分析,探究不同退耕还林林分对林下土壤肥力状况的影响,并为今后退耕还林树种选择提供一定依据。研究结果表明:1土壤水分和孔隙随土层增加而逐渐降低。除柏树外,其他林分林下土壤平均含水量高于未退耕玉米地,且桉树林下土壤浅层含水量最高为33%。水杉林下土壤容重平均值比玉米地减少14%,毛管孔隙度增加58%。此外,花椒、桉树、杜仲、栾树、桑树林下土壤孔隙状况均比对照玉米地好。2土壤有机质、全氮、速效氮等含量随土层增加而减少。7种林分林下土壤有机质、全氮、全钾含量平均值都高于玉米地,其中栾树、桑树、水杉林下土壤有机质和全氮含量均高出玉米地100%以上。而玉米地土壤速效氮、全磷、速效磷、速效钾含量平均值则高于其他7种林分。3栾树、桑树、水杉林下土壤肥力综合得分分别位列前三,玉米地排名第四,柏树、花椒、桉树、杜仲次之。从土壤改良角度出发,该地区树种选择可优先考虑栾树、桑树、水杉,柏树、花椒、桉树、杜仲则需慎重选择。This study selected seven different forest stands of farmland returned to woodland in Hechuan District of Chongqing. The objectives of this study were to compare soil physical and chemical properties at different depth between different forest stands of farmland, evaluate the effect of different forest stands of farmland returned to woodland on soilfertility by means of comparative analysis, and provide a certain basis for the selection of tree species of farmland returned to woodland.Soil moisture and porosity gradually reduced with the increase of soil depth. Soil moisture contents of forest stands were higher than that of cornfields not returned to woodlandexcept cypresses.And moisture contents of surface soil under the eucalyptus forest reached up to 33%. Soil bulk density reduced by 14%and capillary porosity increased by 58% in the metasequoia forest. In addition, soil porositieswere better under the forests of Chinese prickly ash, eucalyptus, cortex eucommiae, goldenrain tree and mulberry than underthe cornfields not returned to woodland. Soil organic matter, total nitrogen, and available nitrogen decreased with the increase of soil layer. And they were higher under the 7 forest stands than under the cornfields not returned to woodland. Soil organic matter and total nitrogen contents were 100% higherunder goldenrain tree, mulberry, and metasequoia forest than under cornfields; while the contents of available nitrogen, total phosphorus, available phosphorus and available potassium were higher in the cornfield soil than in other 7 forest stands. The composite score of soil fertility decreased following the order:goldenrain, mulberry, metasequoia tree, cornfield, cypress, Chinese prickly ash, eucalyptus and cortex eucommiae. Considering of soil improvements,the selection of tree speciesshould give priorities to goldenrain tree, mulberry and metasequoia and then carefully choose cypress, Chinese prickly ash, eucalyptus and cortex eucommiae.

关 键 词：退耕还林 林分类型 土壤理化性质 主成分分析 

分 类 号：S714.6[农业科学—林学]