Chen Chen, Han Hui, Meng Ya, Gong Haiqing, Jia Rui, Xu Ting, Ding Guo-Chun, Li Ji
College of Resources and Environmental Science, Beijing Key Laboratory of Biodiversity and Organic Farming, China Agricultural University, Beijing, China.
Organic Recycling Institute (Suzhou), China Agricultural University, Suzhou, China.
Appl Microbiol Biotechnol. 2021 Mar;105(6):2559-2572. doi: 10.1007/s00253-021-11189-y. Epub 2021 Mar 2.
Nitrate leaching is severe in greenhouse where excessive nitrogen is often applied to maintain high crop productivities. In this study, we investigated the effects of carbon amendment in the subsoil on nitrate leaching and the emission of greenhouse gases (CH and NO) using a soil column experiment. Carbon amendment resulted in over 39% reduction in nitrate leaching and 25.3% to 60.6% increase of total N content in the subsoil zone as compared to non-amended control. Strikingly, the abundance of nirS, nosZ, and 16S rRNA were higher in the treatment than the corresponding controls while no significant effect was detected for nirK. Carbon amendment explained 14%, 10%, and 4% of the variation in the community of nosZ, nirS, and nirK, respectively. It also considerably (more than 7 times) enriched genera such as Anaerovorax, Pseudobacteroides, Magnetospirillum, Prolixibacter, Sporobacter, Ignavibacterium, Syntrophobacter, Oxobacter, Hydrogenispora, Desulfosporomusa, Mangrovibacterium, and Sporomusa, as revealed by the analysis of 16S rRNA amplicon. Network analysis further uncovered that carbon amendment enriched three microbial hubs which mainly consists of positively correlated nirS, nosZ, and anaerobic bacterial populations. In summary, carbon amendment in the subsoil mitigated nitrate leaching and increased the nitrogen pool by possible activation of denitrifying and anaerobic bacterial populations. KEY POINTS: • Carbon amendment in subsoil reduced NO leaching by over 39% under high N input. • Carbon amendment increased the total N in subsoil from 25.3% to 60.6%. • Carbon amendment enriched nirS- and nosZ-type denitrifying bacteria in subsoil.
在温室中，由于经常施用过量氮肥以维持高作物产量，硝酸盐淋失问题严重。在本研究中，我们通过土柱实验研究了底土碳添加对硝酸盐淋失和温室气体（CH和NO）排放的影响。与未添加碳的对照相比，碳添加使硝酸盐淋失减少了39%以上，底土区域总氮含量增加了25.3%至60.6%。令人惊讶的是，处理组中nirS、nosZ和16S rRNA的丰度高于相应对照组，而nirK未检测到显著影响。碳添加分别解释了nosZ、nirS和nirK群落变异的14%、10%和4%。16S rRNA扩增子分析表明，它还显著（超过7倍）富集了Anaerovorax、Pseudobacteroides、Magnetospirillum、Prolixibacter、Sporobacter、Ignavibacterium、Syntrophobacter、Oxobacter、Hydrogenispora、Desulfosporomusa、Mangrovibacterium和Sporomusa等属。网络分析进一步发现，碳添加富集了三个微生物枢纽，主要由正相关的nirS、nosZ和厌氧细菌种群组成。总之，底土碳添加通过可能激活反硝化和厌氧细菌种群减轻了硝酸盐淋失并增加了氮库。要点：• 在高氮输入下，底土碳添加使NO淋失减少了39%以上。• 碳添加使底土总氮增加了25.3%至60.6%。• 碳添加富集了底土中nirS型和nosZ型反硝化细菌。
