| Title: | Synthesis of artificial humic acid-urea complex improves nitrogen utilization |
| Author(s): | Jin Y; Zhang X; Yuan Y; Lan Y; Cheng K; Yang F; |
| Address: | "School of Water Conservancy and Civil Engineering, Northeast Agricultural University, Harbin, 150030, China; Heilongjiang Provincial International Joint Laboratory of Smart Soil, Harbin, 150030, China. Heilongjiang Provincial International Joint Laboratory of Smart Soil, Harbin, 150030, China; College of Engineering, Northeast Agricultural University, Harbin, 150030, China. Electronic address: chengkui@neau.edu.cn. School of Water Conservancy and Civil Engineering, Northeast Agricultural University, Harbin, 150030, China; Heilongjiang Provincial International Joint Laboratory of Smart Soil, Harbin, 150030, China. Electronic address: yangfan_neau@163.com" |
| DOI: | 10.1016/j.jenvman.2023.118377 |
| ISSN/ISBN: | 1095-8630 (Electronic) 0301-4797 (Linking) |
| Abstract: | "The inefficient use of conventional nitrogen (N) fertilizers leads to N enrichment in the soil, resulting in N loss via runoff, volatilization and leaching. While using artificial humic acid to prepare novel N fertilizer is a good choice to improve its efficiency, the high heterogeneity of artificial humic acid limits its structural analysis and utilization efficiency. To solve above problems, this work mainly carried out the fractionation experiments, melt penetration experiments and soil incubation experiments. The results revealed that four fractions with different aromatization degree and molecular weights were obtained by the newly proposed continuous dissolution method, particular in the extraction solution of pH = 3-4, which were extracted with the highest aromatization degree. Furthermore, artificial humic acid urea complex fertilizers prepared at pH = 3-4 significantly improved the release of NH(4)(+)-N by 38.32% on days 7 and NO(3)(-)-N by 10.30% on days 14, compared to urea application. The highly aromatic complex fertilizer with loading of urea-N was able to supply more inorganic N to the soil on days 3-14 (low molecular weight N) and to maintain a higher N content on days 70 (highly aromatized N). This can partially offset the mineralization of readily available organic N, buffering the immobilization of inorganic N from the soil when unstable organic compounds (e.g. conventional urea) were incorporated. A-HAU(3-4) addition on days 70, Proteobacteria and Actinobacteriota were found to be the dominant phylum in the soil and the relative abundance of Endophytic bacteria was increased, which was conducive to the improvement of soil N utilization efficiency and soil N sequestration. Therefore, the preparation of artificial humic urea fertilizer with high aromatization degree or low molecular weight were an effective way to improve N utilization efficiency in the initial stages of soil incubation and maintain N fixation in the later stages of soil incubation. The future application of the strategy presented by this study would have an important ecological significance for alleviating agricultural N pollution" |
| Keywords: | *Humic Substances/analysis *Fertilizers/analysis Urea Soil/chemistry Agriculture/methods Nitrogen/analysis Artificial humic acid Microbial community abundance Soil nitrogen utilization Structural heterogeneity; |
| Notes: | "MedlineJin, Yongxu Zhang, Xi Yuan, Yue Lan, Yibo Cheng, Kui Yang, Fan eng England 2023/06/23 J Environ Manage. 2023 Oct 15; 344:118377. doi: 10.1016/j.jenvman.2023.118377. Epub 2023 Jun 20" |
