三峡库区土壤颗粒、养分及其耦合效应的移土培肥响应特征

Response Characteristics of Soil Particles,Nutrient and Their Coupling Effect to Soil Transfer and Muck Increase Project in the Three Gorges Reservoir Area

三峡库区移土培肥工程通过对淹没区表层土壤资源的二次分配和有效利用,对工程覆土区的生态效益和潜在经济效益有重要的影响。采用差异显著性及相关性等统计学原理的方法,对比分析三峡库区重庆段开县4种主要土地利用类型/覆被条件下,土壤颗粒、养分及其耦合效应的移土培肥响应特征。结果表明:(1)采用移土培肥和未采用移土培肥相比较,4种土地利用/覆被类型土壤养分整体均值的增加范围为5.3%～142.9%;土壤颗粒分布中,粉粒含量的总体均值减少了3.8%～32.7%,而粘粒增加了30.1%～325.2%;土壤可蚀性K值总体均值的比值在(1∶1.042)～(1∶1.440)之间。(2)养分均值在组间和组内都大致表现出差异显著(P<0.05);土壤颗粒分布在组间比较中,除收割地外的其他3种土地利用/覆被类型土壤,仅粘粒含量存在差异显著,而在组内比较中,砂粒和粉粒都表现出差异显著;在土壤可蚀性K值的组间和组内比较中,仅有收割地的土壤可蚀性K值存在差异显著性。(3)在采用移土培肥工程措施后,豌豆地、红薯地以及柑橘地这三类土地利用/覆被类型的土壤颗粒分布对土壤侵蚀敏感强度的影响要高于其土壤整体养分的影响;而对于收割地,则是其土壤整体养分的含量对土壤抗侵蚀能力的贡献比土壤颗粒分布的贡献更大。

Soil transfer and muck increase project（STMIP） which means the access to the redistribution as well as the efficient utilization of surface layer soil resource in the inundated areas of Three Gorges Reservoir areas（TGRA） has significant influence on the ecological and potential economic benefits in the areas of STMIP. Based on the comparisons and analysis of significance of difference and correlation, the responding characters of soil particle, nutrient and their coupling effect which was belonged to four main kinds of land- use in the Kaixian, Chongqing city of TGRA to the STMIP was analyzed. The results show that： （1）By comparing with the soil untreated with STMIP（unt-STMIP）, the nutrient increments of four main kinds of land-use soil treaded with STMIP（t-STMIP） ranged from 5.3% to 142.9% while the slit content decrement ranged from 3. 8% to 32. 7% as well as the clay content increment ranged from 30. 1% to 325. 2%. Meanwhile the ratio of soil erodibility of t-STMIP and unt-STMIP ranged between 1 ： 1. 042 and 1 ： 1. 440. （2）Average nutrient between comparison groups（CG） showed significant difference as well as the average nutrient of internal group（IG）（P〈0.05）; in CG, based on the difference significance analysis, clay content in three kinds of land-use including Lpomoea batatas, Citrus reticulata Banco and Pisum sativum Linn. only demonstrated significant difference, but in IG, the silt and sand content in all the land-use illustrated significant difference; otherwise both in CG and IG, the value of soil erodibility in mowing land only displayed significant difference. （3）In the t-STMIP, comparing with the influence of soil nutrient, the soil particle distribution（PSD） had stronger influence on the soil erodibility in the Lpomoea batatas, Citrus reticulata Banco and Pisum sativum Linn. land-use. With comparison of the PSD, soil nutrient had more contribution of soil erosion resistance in mowing land.