Xie Jun, Wang Zi-Fang, Wang Ying-Yan, Xiong Zi-Yi, Gao Ming
College of Resources and Environment, Southwest University, Chongqing 400715, China.
College of Resources and Environmental Engineering, Mianyang Teachers' College, Mianyang 621000, China.
Huan Jing Ke Xue. 2023 Aug 8;44(8):4565-4574. doi: 10.13227/j.hjkx.202209235.
To clarify the effect of chemical fertilizer and manure combined with biochar on denitrifying microorganisms and denitrification potential of rhizosphere soil, a pot experiment growing lemon was conducted involving five treatments, namely no fertilization (CK), chemical fertilizer (CF), manure (M), chemical fertilizer combined with biochar (CFBC), and manure combined with biochar (MBC). We determined the characteristics of the rhizosphere soil , and type denitrifying bacteria populations; denitrification potential; and soil environmental factors to clarify the effects of chemical and manure combined with biochar on denitrification. Our results showed that compared with that in CK, the CF treatment reduced the rhizosphere soil denitrification potential by 47.7%, whereas the M and MBC treatments increased the denitrification potential by 2192.7% and 1989.9%, respectively. The M and MBC treatments increased the gene copy number of and , the CF and CFBC treatments decreased the gene copy number of and , and all four fertilization treatments increased the gene copy number of Stepwise regression analysis showed that pH was the main factor for the abundance of -type denitrifying bacteria and SOM and NH-N were the main factors for the abundance of -type denitrifying bacteria, whereas pH, NO-N, and N/P were main factors for the abundance of -type denitrifying bacteria. The results of partial least squares analysis indicated that the abundance of type denitrifying bacteria, pH, TN, and N/P were the main factors affecting rhizosphere denitrification potential. Therefore, in acidic purple soil, and type denitrifying bacteria were the main drivers of the soil denitrification process in lemon rhizospheres under chemical fertilizer and pig manure combined with biochar, whereas fertilizer affected the rhizosphere soil denitrification process by regulating soil pH, TN, and N/P.
为阐明化肥与有机肥配施生物炭对根际土壤反硝化微生物及反硝化潜力的影响，开展了一项盆栽柠檬试验，设置了5个处理，分别为不施肥（CK）、施化肥（CF）、施有机肥（M）、化肥配施生物炭（CFBC）和有机肥配施生物炭（MBC）。我们测定了根际土壤特性、反硝化细菌种群类型、反硝化潜力以及土壤环境因子，以阐明化肥与有机肥配施生物炭对反硝化作用的影响。结果表明，与CK相比，CF处理使根际土壤反硝化潜力降低了47.7%，而M和MBC处理分别使反硝化潜力提高了2192.7%和1989.9%。M和MBC处理增加了narG和nirS的基因拷贝数，CF和CFBC处理降低了narG和nirS的基因拷贝数，所有4种施肥处理均增加了nosZ的基因拷贝数。逐步回归分析表明，pH是影响nirK型反硝化细菌丰度的主要因素，SOM和NH₄⁺-N是影响nirS型反硝化细菌丰度的主要因素，而pH、NO₃⁻-N和N/P是影响nosZ型反硝化细菌丰度的主要因素。偏最小二乘分析结果表明，nirK型反硝化细菌丰度、pH、TN和N/P是影响根际反硝化潜力的主要因素。因此，在酸性紫色土中，nirK和nirS型反硝化细菌是化肥和猪粪配施生物炭处理下柠檬根际土壤反硝化过程的主要驱动因素，而肥料通过调节土壤pH、TN和N/P影响根际土壤反硝化过程。
