Phosphorus speciation and colloidal phosphorus responses to short-term cessation of fertilization in a lime concretion black soil  

作　　者：Shanshan BAI Jinfang TAN Zeyuan ZHANG Mi WEI Huimin ZHANG Xiaoqian JIANG 

机构地区：[1]School of Agriculture,Sun Yat-sen University,Guangzhou 510275,China [2]Shenzhen Campus of Sun Yat-sen University,Shenzhen 518107,China [3]Modern Agricultural Innovation Center,Henan Institute of Sun Yat-sen University,Zhumadian 463400,China [4]Institute of Agricultural Resources and Regional Planning,Chinese Academy of Agricultural Sciences/National Engineering Laboratory for Improving Quality of Arable Land,Beijing 100081,China

出　　处：《Pedosphere》2023年第6期948-959,共12页土壤圈（英文版）

基　　金：supported by the National Natural Science Foundation of China (No. 41907063);the Foundation of Modern Agricultural Innovation Center, Henan Institute of Sun Yat-sen University, China (No. N2021-002)。

摘　　要：Long-term excessive application of mineral fertilizer has led to soil acidification and phosphorus(P) accumulation, increasing the risk of P loss and environmental pollution, and cessation of fertilization is widely considered as a cost-effective management strategy to relieve this situation;however, how such cessation influences P speciation and concentrations in a bulk soil and colloidal fractions and whether decreasing P concentration might maintain soil fertility remain unclear. In this study, the effects of long-term fertilization(ca. 40 years) and short-term cessation of fertilization(ca. 16 months) on inorganic, organic,and colloidal P in lime concretion black soil were investigated using P sequential fractionation and31P nuclear magnetic resonance spectroscopy. After long-term fertilization, available P, dicalcium phosphate, iron-bound P, orthophosphate monoesters, and orthophosphate diesters increased significantly, but soil p H decreased by ca. 2.8 units, indicating that long-term fertilization caused soil acidification and P accumulation and changed P speciation markedly. In contrast, short-term fertilization cessation increased soil p H by ca. 0.8 units and slightly reduced available and inorganic P. Available P after fertilization cessation was 22.9–29.8 mg kg-1, which was still sufficient to satisfy crop growth requirements. Additionally, fertilization cessation increased the proportions of fine colloids(100–450 nm, including nontronite and some amorphous iron oxides) and drove a significant release of iron/aluminum oxide nanoparticles(1–100 nm) and associated P with orthophosphate and pyrophosphate species. In summary, short-term fertilization cessation effectively alleviated soil acidification and inorganic P accumulation, while concomitantly maintaining soil P fertility and improving the potential mobilization of P associated with microparticles.

关 键 词：Fe/Al oxide nanoparticles fine colloids P accumulation 31pP nuclear magnetic resonance P sequential fractionation soil acidification 

分 类 号：S153.6[农业科学—土壤学]