Hu Jiazhen, Wang Jie, Yang Shihong, Qi Suting, Jiang Zewei, Dai Huidong, Zhou Jiaoyan
College of Agricultural Science and Engineering, Hohai University, 8th Focheng West Road, Jiangning District, Nanjing, 210098, China.
Development Center for Science and Technology of Rural Water Resources of Jiangsu Province, Nanjing, 210029, China.
Environ Sci Pollut Res Int. 2023 Jan;30(3):7770-7785. doi: 10.1007/s11356-022-22728-z. Epub 2022 Aug 31.
Growing evidence points to the controlled irrigation (CI) and biochar application (BA) having agricultural economic value and ecological benefits, but their synergistic effect and microbial mechanism of nitrogen conversion remain unknown in paddy fields. The effects of different BA (0, 20, 40 t/hm) on the soil nitrogen functional transformation microbial genes (nifH, AOA-amoA, AOB-amoA) in different irrigation (CI, flooding irrigation) were clarified. After one seasonal growth of paddy, the correlation between the abundance of functional genes OUT and soil nitrogen transformation environment factors during the typical growth period was analyzed. High-throughput sequencing results illustrated that the application of CC (40 t/hm biochar) increased the nifH genes bacterial community abundance; the abundance of dominant microorganism increased by 79.68~86.19%. Because biochar can potentially control the rates of N cycling in soil systems by adsorbing ammonia and increasing NH storage, it increased soil NH-N and NO-N content by 60.77% and 26.14%, improving microbial nitrogen fixation. Rare species Nitrosopumilus, Nitrosococcus, and Methylocystis appeared in biochar treatments group, which increased the diversity of microbial in paddy. The combined use of CI and BA affected soil inorganic nitrogen content, temperature (T), pH, Eh, etc., which affected urease, urea hydrolysis, and nitrogen functional transformation microorganism genes. Correlation analysis shows that soil NH-N, T, and Eh, respectively, are significant factors for the formation of nifH, AOA-amoA, and AOB-amoA soil bacterial communities, respectively. This study suggests that to maintain the biodiversity of soil and realize the sustainable development of rice cultivation, CI is of great importance in combination with BA.
越来越多的证据表明，控制性灌溉（CI）和生物炭施用（BA）具有农业经济价值和生态效益，但它们在稻田中的协同效应以及氮转化的微生物机制仍不清楚。本研究阐明了不同生物炭用量（0、20、40 t/hm）对不同灌溉方式（CI、淹水灌溉）下土壤氮功能转化微生物基因（nifH、AOA-amoA、AOB-amoA）的影响。在水稻一季生长后，分析了典型生育期功能基因OUT丰度与土壤氮转化环境因子之间的相关性。高通量测序结果表明，施用40 t/hm生物炭提高了nifH基因细菌群落丰度，优势微生物丰度增加了79.68%~86.19%。由于生物炭可通过吸附氨和增加NH储存量来潜在控制土壤系统中的氮循环速率，使土壤NH-N和NO-N含量分别提高了60.77%和26. I4%，改善了微生物固氮作用。生物炭处理组出现了罕见物种亚硝化侏儒菌、亚硝化球菌和甲基孢囊菌，增加了稻田微生物的多样性。CI与BA联合使用影响土壤无机氮含量、温度（T）、pH、Eh等，进而影响脲酶、尿素水解和氮功能转化微生物基因。相关性分析表明，土壤NH-N、T和Eh分别是nifH、AOA-amoA和AOB-amoA土壤细菌群落形成的显著因素。本研究表明，为维持土壤生物多样性并实现水稻种植的可持续发展，CI与BA结合具有重要意义。
