不同农田防护林下盐碱地土壤水分特征曲线差异对比  

Comparison of soil water characteristic curves of saline-alkali land under different farmland shelterbelts

作　　者：陈印平[1,2] 夏江宝[1] 刘俊华[1] CHEN Yinping;XIA Jiangbao;LIU Junhua(Binzhou University,Shandong Provincial Key Laboratory of Eco-environmental Science for Yellow River Delta,256603,Binzhou,Shandong,China;Shandong Agricultural University,College of Resources and Environment,271018,Tai'an,Shandong,China)

机构地区：[1]滨州学院,山东省黄河三角洲生态环境重点实验室,山东滨州256603 [2]山东农业大学资源与环境学院,山东泰安271018

出　　处：《中国水土保持科学》2019年第5期18-24,共7页Science of Soil and Water Conservation

基　　金：山东省重大科技创新工程项目“盐碱地林业生态功能提升关键技术”(2017CXGC0316);山东省重点研发计划“黄河三角洲盐碱地农田林网生态工程治理及配套生物修复技术研究与示范”(2015GNC111022)

摘　　要：揭示黄河三角洲农田防护林土壤持水特征,探讨适宜的土壤水分特征曲线,为黄河三角洲农田防护林蓄水保土提供理论依据。以毛白杨林、白蜡林和混交林(毛白杨+白蜡)等黄河三角洲农田林网建设的3种典型农田防护林为研究对象,利用烘干法、环刀法和离心法测定土壤含水量、物理性质及持水性,分析其土壤水分状况及不同土层水分特征曲线的变化动态,运用决定系数和均方根误差分析比较Gardner和van Genuchten模型对实测数据的拟合效果。研究结果表明:黄河三角洲防护林土壤含水量因吸力不同呈下降快速-缓慢-平稳的变化规律,随着水吸力的增大,比水容量均单调递减且无限趋近于零;在低吸力段失水快,水分易流失,随着吸力的增强,土壤持水性增强。分析Gardner和van Genuchten模型的参数,结果表明混交林的持水能力最强,其次是毛白杨林,白蜡林最弱。由分析2种模型的决定系数(R2)和均方根误差(RMSE)可知,van Genuchten模型对黄河三角洲农田防护林的实测土壤水分特征曲线的拟合效果优于Gardner模型。[Background]The Yellow River Delta is the largest estuarine wetland ecosystem in the warm temperate zone in China.However,rainfall was less and the mineral content in underground water was high,which caused soil salinization and alkalization.In this region,the coordinated adaptation of water between plant and soil is the key issue in agricultural development.Therefore,studying the water retention ability of farmland shelterbelts is very important.[Methods]Three typical plant configuration modes Populus tomentosa forest,Fraxinus chinensis forest and mixed forest(P.tomentosa+F.chinensis)were selected as research object,the methods of drying and cutting-ring were used to study water content and physical properties of soil.The soil water contents under different suctions were measured using a high-speed centrifuge,and the characteristic curve were obtained using the mathematical models of Gardner and van Genuchten.Then,parameters such as soil water characteristic curves,soil water capacity,specific water capacity and soil water retention were compared among different farmland shelterbelts.The RMSE(Root Mean Squared Error)and R2 were used to evaluate the fitting of two models for soil water characteristic curves.[Results]In three farmland shelterbelts in Yellow River Delta,with the increase of suction,the variation of soil water content declined fast(-1.0×10^5-0 Pa)to slow(-3.5×10^5--1.0×10^5 Pa)to steady(-11.0×10^5--3.5×10^5 Pa).Specific water capacity decreased monotonously and tended to zero infinitely.Soil water characteristic curves at different soil depths showed a steep trend and strong water loss in low suction range,while they presented a smooth and slow trend,with a high water retention ability in high suction range.The soil water retention ability in the three forests was as follows:mixed forest>P.tomentosa forest>F.chinensis forest.The mean value of R2 and RMSE of van Genuchten model was 0.980 and 0.028,that of Gardner model was 0.999 and 0.002,on the whole,the van Genuchten model was superior to the

关 键 词：土壤持水性 土壤水分特征曲线 农田防护林 盐碱地 黄河三角洲 

分 类 号：S152.[农业科学—土壤学]