长江流域稻-油轮作区土壤磷库现状及环境风险分析  

Status of Soil Phosphorus Pool and Environmental Risk Assessment in Rice-Oilseed Rape Rotation Area in the Yangtze River Basin

作　　者：闫金垚 郭丽璇 王昆昆 廖世鹏[1] 陆志峰[1] 丛日环[1] 李小坤[1] 任涛[1] 鲁剑巍[1] YAN Jinyao;GUO Lixuan;WANG Kunkun;LIAO Shipeng;LU Zhifeng;CONG Rihuan;LI Xiaokun;REN Tao;LU Jianwei(Microelement Research Center,Huazhong Agricultural University/Key Laboratory of Arable Land Conservation(Middle and Lower Reaches of Yangtze River),Ministry of Agriculture and Rural Affairs,Wuhan 430070,China)

机构地区：[1]华中农业大学微量元素研究中心/农业农村部长江中下游耕地保育重点实验室,武汉430070

出　　处：《土壤学报》2023年第1期247-257,共11页Acta Pedologica Sinica

基　　金：国家重点研发计划(2017YFD0200206);国家现代农业产业技术体系(CARS-12)资助。

摘　　要：明确长江流域水稻-油菜轮作种植区土壤磷(P)库现状,评估土壤磷淋失风险,以期为长江流域水稻-油菜轮作体系合理施磷提供参考。2018年4—5月在长江流域水稻-油菜轮作典型种植区域的14个省(市/区)采集油菜收获后的耕层土壤样品247个,测定土壤全磷、有效磷(Olsen-P)和可溶性磷(CaCl2-P)含量,并参考土壤全磷和Olsen-P分级指标,明确我国长江流域水稻-油菜轮作种植区域土壤磷丰缺现状,建立Olsen-P与CaCl2-P之间的定量关系。还根据Olsen-P分级选取72个样本进行Hedley磷分级测试,分析了水稻-油菜轮作种植区域土壤磷库分布特征。结果表明:长江流域水稻-油菜轮作种植区域耕层土壤全磷、Olsen-P和CaCl2-P平均含量分别为0.62 g·kg^(-1)、23.2 mg·kg^(-1)和0.49 mg·kg^(-1)。土壤全磷在长江上、中、下游间无明显差异,区域整体48.6%处于丰富状态。土壤Olsen-P缺乏和过量的现象并存,占比分别为23.1%和31.1%,土壤Olsen-P缺乏和过量的区域分别集中在长江中游和长江下游区域。长江流域水稻-油菜轮作种植区域土壤磷库以无机磷为主,平均占比达到82.2%。H2O-Pi、NaHCO3-Pi、NaOH-Pi、HCl-Pi、NaHCO3-Po、NaOH-Po和Residual-P磷库平均含量分别为10.8、46.8、115.6、218.6、22.3、104.9和193.8 mg·kg^(-1)。随着土壤Olsen-P水平的增加,NaHCO3-Pi和NaOH-Pi含量明显增加,稳定态磷库(HCl-Pi和Residual-P)含量相对稳定。长江流域水稻-油菜轮作种植区域耕层土壤Olsen-P和CaCl2-P的关系符合双直线模型,出现突变点时Olsen-P含量为39.9 mg·kg^(-1),对应的CaCl2-P含量为0.6 mg·kg^(-1)。当土壤Olsen-P含量大于39.9 mg·kg^(-1)时,土壤磷素淋失风险增加。整体而言,长江流域水稻-油菜轮作种植区域土壤磷含量呈上升趋势,土壤Olsen-P平均含量达到适宜养分供应水平,且存在13.0%的区域处于磷素高淋失风险状态。土壤磷素主要积累在稳定态磷库中,因此,应重视磷肥�【Objective】The objective of this study was to clarify the status of soil phosphorus(P)pools in rice-oilseed rape rotation areas in the Yangtze River Basin,and assessed the risk of soil P leaching.Alse it aimed to provide a reference for reasonable phosphorus application in the rice-oilseed rape rotation system in the Yangtze River Basin.【Method】From April to May 2018,247 soil samples of the cultivated layer after the oilseed rape harvest were collected in 14 provinces(cities/districts)around the Yangtze River Basin in typical rice-oilseed rape rotation regions to determine soil total phosphorus,available phosphorus(Olsen-P)and soluble phosphorus(CaCl 2-P).With reference to soil total phosphorus and available phosphorus grading indexes,the current status of soil phosphorus abundance and deficiency in rice-oilseed rape rotation areas in the Yangtze River Basin was clarified,and the quantitative relationship between Olsen-P and CaCl2-P was established.According to the available phosphorus grading,72 samples were selected for Hedley phosphorus fraction determination,and the distribution characteristics of soil phosphorus pool in rice-oilseed rape rotation were analyzed.【Result】The results showed that the average content of total phosphorus,available phosphorus and CaCl 2-P in cultivated soils of rice-oilseed rape rotation area in the Yangtze River Basin were 0.62 g·kg^(-1),23.2 mg·kg^(-1) and 0.49 mg·kg^(-1),respectively.There was no significant difference in total phosphorus between the upper,middle and lower reaches of the Yangtze River,and 48.6%of the total area was in a state of abundance.The lack and excess of soil available phosphorus coexist,accounting for 23.1%and 31.1%,respectively.The areas of soil available phosphorus deficiency and excess were concentrated in the middle and lower reaches of the Yangtze River,respectively.Also the soil phosphorus pool was dominated by inorganic phosphorus,accounting for an average of 82.2%.The average content of H 2O-Pi,NaHCO 3-Pi,NaOH-Pi,HCl-Pi,NaHCO 3-Po,N

关 键 词：稻-油轮作 OLSEN-P CaCl2-P 环境阈值 Hedley磷分级 

分 类 号：S158[农业科学—土壤学]