珠三角赤红壤常年连作菜地土壤磷库特征  

Characteristics of the soil phosphorus pool in continuously cultivated vegetable fields in the latosolic red soil zone of the Pearl River Delta

作　　者：宁建凤 陈勇 姚建武 梁紫薇 曾瑞锟 王荣辉 李彤 NING Jian-feng;CHEN Yong;YAO Jian-wu;LIANG Zi-wei;ZENG Rui-kun;WANG Rong-hui;LI Tong(Institute of Agricultural Resources and Environment,Guangdong Academy of Agricultural Sciences,Key Laboratory of Plant Nutrition and Fertilizer in South Region,Ministry of Agriculture,Guangdong Key Laboratory of Nutrient Cycling and Farmland Conservation,Guangdong Engineering Research Center for Monitoring and Prevention of Agricultural Non-point Source Pollution,Guangzhou 510640,China)

机构地区：[1]广东省农业科学院农业资源与环境研究所,农业部南方植物营养与肥料重点实验室,广东省养分资源循环利用与耕地保育重点实验室,广东省农业面源污染监测评估与防控工程技术研究中心,广东广州510640

出　　处：《草业学报》2025年第2期133-148,共16页Acta Prataculturae Sinica

基　　金：国家自然科学基金项目(编号31701996);广东省科技计划项目(编号2021B1212050019);广东省农业科学院低碳中心与碳中和研究中心项目(编号XTXM202204)资助。

摘　　要：磷既是作物营养必需元素也是重要面源污染因子,研究集约化菜地土壤磷库特征,为有针对性地制定菜地磷养分管理措施,降低菜地磷素面源污染风险提供依据。以珠三角地区(广州、江门、肇庆、惠州等地)赤红壤常年菜地系统为研究对象,共采集89份城郊菜地土壤样品,采用修正的Hedley磷库分级法分析土壤磷组分,探明土壤性质与磷库相关性。赤红壤菜地土壤磷库以无机磷(Pi)为主要赋存形态,无机磷在磷库占比达88%,有机磷(Po)、残余磷在磷库占比均较低,分别为8.1%、3.9%。菜地土壤无机磷含量为1176.78 mg·kg^(-1),远高于有机磷(109.03 mg·kg^(-1))和残余磷含量(52.19 mg·kg^(-1))。无机磷库中,H2O-Pi、NaHCO_(3)-Pi、NaOH-Pi、稀HCl-Pi、浓HCl-Pi含量分别为46.35 mg·kg^(-1)、264.64 mg·kg^(-1)、427.45 mg·kg^(-1)、274.82 mg·kg^(-1)、163.52 mg·kg^(-1),在总磷中相应占比分别为3.32%、20.74%、31.29%、16.32%、14.13%。有机磷库中,NaHCO_(3)-Po、NaOH-Po、浓HCl-Po含量分别为27.24 mg·kg^(-1)、62.35 mg·kg^(-1)、19.44 mg·kg^(-1),占总磷比例依次为2.33%、5.70%、1.56%。NaOH提取磷(NaOH-P)在菜地无机磷库、有机磷库中均占主导地位。从土壤磷活性角度分析,活性磷、中等活性磷、稳定性磷含量分别为338.23 mg·kg^(-1)、764.62 mg·kg^(-1)、235.15 mg·kg^(-1),在总磷中相应占比分别为25.3%、57.1%、17.6%。几乎全部89个样点土壤活性磷与中等活性磷之和在总磷库占比均超过50%。土壤有机质、全氮、碱解氮、速效钾、阳离子交换量(CEC)均与活性磷、中等活性磷含量呈显著正相关,且存在浓度效应。赤红壤菜地土壤总体上磷含量丰富、有效性高。施肥、耕作管理等人为活动及赤红壤特性共同影响土壤磷库形成。考虑到赤红壤区的强降水气候特征,常年菜地磷素面源污染风险大,应注意通过合理施肥降低磷的污染风险。Phosphorus(P)is an essential nutrient for crops,and is a key factor that is monitored in the control of non-point pollution.It is important to clarify the characteristics of the soil P pool to devise strategies to manage P levels and reduce P-related non-point pollution in intensively cultivated vegetable fields.In this study,we determined the characteristics of the soil P pool in the perennial vegetable fields in the latosolic red soil zone of the Pearl River Delta.A total of 89 soil samples were collected from the surface layer(0-20 cm)of vegetable fields located in the suburbs of Guangzhou,Jiangmen,Zhaoqing,and Huizhou.The composition of the soil P pool in the samples was determined using a modified Hedley method.Correlation analyses were conducted to reveal relationships between soil properties and the P pool.The results show that the proportions of inorganic P(Pi),organic P(Po),and residual P in the soil P pool were 88%,8.1%and 3.9%,respectively,indicating that Pi was the dominant form in the soil P pool.The concentrations of these forms were as follows:Pi(1176.78 mg·kg^(-1)),Po(109.03 mg·kg^(-1)),and residual P(52.19 mg·kg^(-1)).The Pi pool consisted of several fractions,namely H2O-Pi,NaHCO_(3)-Pi,NaOH-Pi,Dli HCl-Pi,and Con HCl-Pi,with concentrations of 46.35 mg·kg^(-1),264.64 mg·kg^(-1),427.45 mg·kg^(-1),274.82 mg·kg^(-1),163.52 mg·kg^(-1),respectively;and proportions of 3.32%,20.74%,31.29%,16.32%,and 14.13%,respectively,in the total P pool.The fractions in the Po pool were NaHCO_(3)-Po,NaOH-Po,and Con HCl-Po,with concentrations of 27.24 mg·kg^(-1),62.35 mg·kg^(-1),and 19.44 mg·kg^(-1),respectively;and proportions of 2.33%,5.70%,and 1.56%,respectively,in the total P pool.The dominant form in both the Po and Pi pools was NaOH-P,specifically NaOH-Pi in the Pi pool and NaOH-Po in the Po pool.In terms of soil P availability,the concentrations of labile P,moderately labile P,and recalcitrant P were 338.23 mg·kg^(-1),764.62 mg·kg^(-1),and 235.15 mg·kg^(-1),respectively.The proportions of labile P,m

关 键 词：赤红壤菜地 Hedley磷库分级法 无机磷组分 有机磷组分 磷有效性 

分 类 号：S15[农业科学—土壤学]