Theoretical Study on the Effects of Spatial Structure of P Complexation Sites on the Soil Phosphorus Activation in Leonardite Humic Acid Complexes  

作　　者：CHE Xin SONG Tao LIU Yong HU Zhao-Ping GAO Jun 车昕;宋涛;刘勇;胡兆平;高军(Kingenta Ecological Engineering Group Co.,Ltd./State Key Laboratory of Nutrition Resources Integrated Utilization,Linyi 276700,China;Linyi Environmental Monitoring Station,Linyi 276000,China;Huazhong Agricultural University,Wuhan 430000,China)

机构地区：[1]Kingenta Ecological Engineering Group Co.,Ltd./State Key Laboratory of Nutrition Resources Integrated Utilization,Linyi 276700,China [2]Linyi Environmental Monitoring Station,Linyi 276000,China [3]Huazhong Agricultural University,Wuhan 430000,China

出　　处：《Chinese Journal of Structural Chemistry》2020年第2期229-242,184,共15页结构化学（英文）

基　　金：supported by the Key R&D project of Shandong Province(No.2016ZDJQ0701);Huazhong Agricultural University Scientific and Technological Self-innovation Foundation(No.2015RC008)。

摘　　要：Humic acid is an important active component in soil environment. The spatial structures of P complexation sites in humic acid complexes play an important role in soil phosphorus activation and fertilizer efficiency. To explore the effects of spatial structure, the three different coordination modes of iron-carboxyl in models were calculated by the ONIOM method available in the Gaussian09 package. The(U)B3LYP hybrid density functional was employed to optimize the configuration for the QM region, and the UFF force field was used to calculate for the MM region. The results show that the different spatial structures influence the soil phosphorus activation by affecting the electronic structure, Gibbs free energy and interaction energy of the models. And the effects are as follows: the unidentate structure model ~6P-Fe-MHA-UD, the bidentate chelating structure model ~6P-Fe-MHA-BD>the bidentate bridging structure model ~5P-Fe-MHA-BD-BG. It can be known that, the fertilizer efficiency can be improved through increasing the proportion of the unidentate structure and the bidentate chelating structure in production engineering. The research provides a theoretical basis for further optimization of the production of humic acid phosphate fertilizer.

关 键 词：leonardite HUMIC acid FERTILIZER efficiency spatial structure phosphorus ACTIVATION ONIOM method 

分 类 号：TQ444.65[化学工程—化学肥料工业] O641.121[理学—物理化学]