西苕溪流域主要经济林土壤磷素流失风险研究  

Potential Risk of Phosphorus Loss from Main Non-Wood Forest Soils in Xitiaoxi Watershed

作　　者：王肖君 王季丰 侯琼 冷明珠 倪吾钟[1] WANG Xiaojun;WANG Jifeng;HOU Qiong;LENG Mingzhu;NI Wuzhong(College of Environmental and Resource Sciences,Zhejiang Provincial Key Laboratory of Agricultural Resources and Environment,Zhejiang University,Hangzhou 310058,China;Bureau of Agriculture and Rural Affairs of Anji County,Zhejiang Province,Anji,Zhejiang 313300,China)

机构地区：[1]浙江大学环境与资源学院,浙江省农业资源与环境重点实验室,杭州310058 [2]浙江省安吉县农业农村局,浙江安吉313300

出　　处：《土壤学报》2021年第2期487-494,共8页Acta Pedologica Sinica

基　　金：国家水体污染控制与治理科技重大专项(2014ZX07101-012)资助。

摘　　要：经济林土壤磷素积累与潜在流失风险的研究对流域内磷素管理和面源污染控制十分必要。通过采样调查和室内分析研究了西苕溪流域主要经济林土壤测试磷的状况及磷素流失的潜在风险,调查采集了西苕溪流域安吉段主要经济林(毛竹、白茶、板栗)土壤样品105个,探讨了土壤理化性质对土壤磷素流失的影响以及土壤有效磷的控制阈值。结果表明,土壤水溶性磷(WEP)与土壤有机碳(SOC)、全磷(TP)呈极显著正相关(P<0.01),模拟酸雨浸提磷(SARP)也与土壤SOC、TP呈极显著正相关(P<0.01),土壤WEP、SARP与pH呈极显著负相关(P<0.01),但决定系数R2分别仅有0.187~0.280,影响相对较小。土壤WEP、SARP与有效磷(Bray 1-P)的关系可用分段线性回归方程描述(P<0.01),R2分别可达0.992、0.991,估算得出,与WEP、SARP相对应的土壤Bray 1-P的阈值分别为93.63、87.68 mg×kg^(-1),后者较前者降低了5.95 mg×kg^(-1)。此外,土壤Bray 1-P含量超过40 mg×kg^(-1)、低于5 mg×kg^(-1)的样品占比分别可达17.14%、38.01%,缺磷与磷过度积累现象并存。土壤磷素的流失风险主要受土壤Bray 1-P、TP、SOC、pH等因素的影响,其中Bray 1-P是最重要的影响因子。酸雨会加大土壤磷素流失的潜在风险,作为酸雨频发区域的西苕溪流域,土壤有效磷水平的限制应更为严格。【Objective】Studies on accumulation and potential loss risk of soil phosphorus in non-wood forest soils are essential to management of soil phosphorus and control of non-point source P pollution in watersheds.So a research project was carried out in the Xitiaoxi watershed.【Method】In the project,a total of 105 soil samples were collected in the main non-wood forests,such as moso bamboo(Phyllostachys heterocycla(Carr.)Mitford cv.Pubescens Mazel ex H.de leh.),white tea(Camellia sinensis(L.)O.Ktze.),chestnut(Castanea mollissima Bl.)in the watershed for lab analysis of concentrations of water-extractable phosphorus(WEP)and simulated-acid-rain-extractable phosphorus(SARP)and some main soil physico-chemical properties such as total nitrogen(TN),total phosphorus(TP),total potassium(TK),alkalyzable nitrogen(AN),available phosphorus(Bray 1-P),readily available potassium(AK),pH,soil organic carbon(SOC).Acid rain set at 4.75 in pH was simulated and prepared with sulphate acid and nitrate acid.Correlation analysis and regression analysis was performed of the obtained data to determine influences of soil physico-chemical properties on the risk of phosphorus runoff loss and threshold of soil available phosphorus.【Result】In the survey area,soil TP content varied in the range of 0.22-0.73 g×kg^(-1)(0.42 g×kg^(-1)on average)and Bray 1-P content in the range of 0.93-313.2 mg×kg^(-1)(30.87 mg×kg^(-1)on average)with coefficient of variation reaching up to 204.7%and the soil samples over 40 mg×kg^(-1)and below 5 mg×kg^(-1)in Bray-P content accounted for 17.14%and 38.01%of all the analyzed ones,respectively;soil WEP content varied in the range of 0.03-38.15 mg×kg^(-1)(2.64 mg×kg^(-1)on average)with coefficient of variation reaching up to 267.5%;and soil SARP content varied in the range of 0.03-42.91 mg×kg^(-1)(2.86 mg×kg^(-1)on average)with coefficient of variation reaching up to 268.6%.It was found that soil WEP and SARP were significantly and positively related to soil organic carbon(SOC)and TP(P<0.01),and negati

关 键 词：西苕溪流域 经济林 土壤测试磷 阈值 模拟酸雨 

分 类 号：S153[农业科学—土壤学] S151.9[农业科学—农业基础科学]