丹江口库区旱地土壤磷淋溶阈值影响因素及其预测  

Factors that affect phosphorus leaching threshold and its prediction in dryland soils of Danjiangkou Reservoir area

作　　者：黄伊静 王杰 阳邦戈 熊怡 耿佟佟 蔡崇法[1] HUANG Yijing;WANG Jie;YANG Bangge;XIONG Yi;GENG Tongtong;CAI Chongfa(College of Resource and Environment,Huazhong Agricultural University,Wuhan 430070,China;Changjiang River Scientific Research Institute,Wuhan 430019,China)

机构地区：[1]华中农业大学资源与环境学院,武汉430070 [2]长江水利委员会长江科学院,武汉430019

出　　处：《农业资源与环境学报》2025年第1期159-168,共10页Journal of Agricultural Resources and Environment

基　　金：国家自然科学基金面上项目(42077067);华中农业大学大学生科技创新基金项目(2021085)。

摘　　要：为探究丹江口库区旱地土壤磷淋溶流失机制及其淋溶阈值的预测,以丹江和汉江的4个小流域为研究区,共采集研究区内20个典型旱作耕地土壤,测定其理化性质与土壤磷吸附特征参数,并通过室内培养试验获得土壤磷淋溶阈值(Phosphorus leaching threshold,P_(lth)),通过路径分析探究了不同土壤P_(lth)对土壤性质及磷吸附特性的响应,采用主成分分析探究了P_(lth)的主控因子,并依此对其进行预测。结果表明:研究区土壤P_(lth)范围在16.34~93.84 mg·kg^(-1)之间,部分样点土壤速效磷(Olsen-P)含量接近甚至高于其P_(lth),具有极大流失风险。相关性分析表明,P_(lth)是众多土壤性质共同作用的结果,与土壤pH呈极显著负相关(R^(2)=0.81,P<0.001),与土壤总磷(Total phosphorus,TP)、水溶性磷(Water-soluble phosphorus,P_(d))和Olsen-P含量呈显著正相关(R^(2)>0.62,P<0.01),并受到土壤磷吸附饱和度(DPS)、零点吸持平衡浓度(EPC0)的显著影响(R^(2)>0.51,P<0.05),在一定程度上也受到胶结物质,如土壤有机质(SOM)和游离态铁铝氧化物(Fe_(d)、Al_(d))的影响。路径分析中,P_(lth)对DPS、pH和Pd的响应更为敏感,总效应系数分别为-0.90、-0.81和0.80,其中,pH影响磷吸附解吸过程的间接效应(-0.49)超过其直接效应(-0.32)。主成分分析表明土壤pH和Olsen-P是影响P_(lth)的最主要因子,可通过多元线性回归方程对丹江口库区旱地土壤P_(lth)进行有效预测。研究表明:P_(lth)对DPS、pH和Olsen-P含量的响应更为敏感,土壤pH和Olsen-P含量是P_(lth)的主控因素,可依此对其进行预测。To investigate the mechanism of phosphorus leaching and loss in dryland soils in Danjiangkou Reservoir area and prediction of its leaching threshold(P_(lth)),20 typical dryland cultivated soils were collected from four sub-basins of Danjiang River and Hanjiang River as the study area,and their physicochemical properties and soil phosphorus adsorption parameters were determined.P_(lth)values were obtained using the indoor incubation test,the response of different soil P_(lth)values to soil properties and phosphorus adsorption characteristics was investigated using path analysis,and the main controlling factors of P_(lth)were investigated and predicted using principal component analysis.The results showed that soil P_(lth)in the study area ranged from 16.34 mg·kg^(-1)to 93.84 mg·kg^(-1),and the content of quick-acting phosphorus(Olsen-P)in some soils was close to or even higher than their P_(lth),which had a great risk of erosion.Correlation analysis showed that P_(lth)was the result of the joint action of many soil properties,and it was significantly negatively correlated with soil pH(R^(2)=0.81,P<0.001),significantly positively correlated with soil total phosphorus(TP),water-soluble phosphorus(Pd),and Olsen-P content(R^(2)>0.62,P<0.01),and significantly affected by soil phosphorus saturation(DPS)and zero point adsorption equilibrium(EPC0)(R^(2)>0.51,P<0.05).To some extent,P_(lth)was also affected by cementing materials such as soil organic matter and free-state iron and aluminum oxides(Fed and Ald);in the path analysis,P_(lth)was more sensitive to the response of DPS,pH,and Pd,with total effect coefficients of-0.90,-0.81,and 0.80,respectively,of which the indirect effect of the pass through of pH influencing the process of phosphorus adsorption and desorption(-0.49)exceeded the direct effect(-0.32).The principal component analysis showed that soil pH and Olsen-P were the most important factors that affected P_(lth),which could be effectively predicted using the multiple linear regression equation for dryland so

关 键 词：农田土壤 淋溶阈值 土壤性质 路径分析 

分 类 号：X53[环境科学与工程—环境工程]