生物炭添加阻控河岸林地氮污染

马玉祥; 安兆龙

doi:10.12171/j.1000-1522.20240303

摘要:

目的探究不同生物炭添加量对河岸林土壤化学性质、酶活性、微生物群落组成的影响，明晰生物炭添加对河岸林地氮污染削减的影响机制，为流域面源污染阻控及生态修复提供科学依据。

方法以河北省保定市清水河沿岸毛白杨人工林为研究对象，采用单因素方差分析和相关性分析方法，分析不同生物炭添加量（0、3、6 t/hm²）对河岸林地阻控氮污染的效果。

结果（1）不同生物炭添加量的毛白杨林地土壤化学性质具有显著性差异（P < 0.05）。同对照相比，3 t/hm²生物炭添加组全氮（TN）、铵态氮（\rmNH_4^ + -N）、硝态氮（\rmNO_3^ - -N）、有机质（SOM）、有机碳（SOC）分别提高 10.39%、46.15%、8.57%、38.03%和51.23%。6 t/hm²生物炭添加组TN、\rmNH_4^ + -N、\rmNO_3^ - -N、SOM、SOC分别提高 26.62%、92.31%、65.00%、78.05%和135.47%。（2）不同生物炭添加量的毛白杨林地土壤酶活性具有显著性差异（P < 0.05）。与对照相比，3 t/hm²生物炭添加组脲酶（S-UE）、硝酸还原酶（S-NR）、亚硝酸还原酶（S-NIR）活性分别提高 35.00%、69.41%和 85.71%。6 t/hm²生物炭添加组S-UE、S-NR、S-NIR活性分别提高63.33%、104.31%和 77.92%。（3）高通量测序结果表明，生物炭添加提高了变形菌门、未分类菌门、拟杆菌门的相对丰度，降低了放线菌门的相对丰度。（4）土壤化学性质、酶活性与细菌优势门的相关性分析表明，SOC、SOM、S-NR、S-NIR是影响土壤微生物群落门水平的主要因子。

结论生物炭添加能提高毛白杨林地土壤对氮素的截留能力，并且增强土壤氮循环相关酶活性，改善土壤微生物群落结构，进而影响土壤中氮素的转化与去除。在不同处理组中，6 t/hm²的添加量表现出最为显著的效果。

Abstract:

Objective This paper explores the effects of different biochar additions on soil chemical properties, soil enzyme activity and microbial community composition of riparian forest, and understands the removal mechanism of nitrogen pollution reduction in riparian forest by biochar addition, so as to provide scientific basis for the prevention and control of non-point source pollution in watershed and ecological restoration technology.

Method Using one-way ANOVA and correlation analysis, the effects of different biochar levels (0, 3, 6 t/ha) on nitrogen pollution control were analyzed in Populus tomentosa along Qingshui River in Baoding, Hebei Province of northern China.

Result (1) There were significant differences in soil chemical properties of forest with different biochar levels (P < 0.05). Compared with control group, total nitrogen, ammonium nitrogen, nitrate nitrogen, organic matter and organic carbon in 3 t/ha biochar addition group increased by 10.39%, 46.15%, 8.57%, 38.03% and 51.23%, respectively. In the 6 t/ha biochar addition group, total nitrogen, ammonium nitrogen, nitrate nitrogen, organic matter and organic carbon increased by 26.62%, 92.31%, 65.00%, 78.05% and 135.47%, respectively. (2) There were significant differences in soil enzyme activities of forest with different biochar levels (P < 0.05). Compared with control group, the activities of urease, nitrate reductase and nitrite reductase in 3 t/ha biochar addition group were increased by 35.00%, 69.41% and 85.71%, respectively. The activities of urease, nitrate reductase and nitrite reductase in 6 t/ha biochar addition group increased by 63.33%, 104.31% and 77.92%, respectively. (3) The results of high-throughput sequencing showed that the addition of biochar increased the relative abundance of Proteobacteria, unclassified bacteria and Bacteroidota, while decreased the relative abundance of Actinobacteriota. (4) The correlation analysis of soil chemical properties, enzyme activities and bacterial dominant phyla showed that organic matter, organic carbon, nitrate reductase and nitrite reductase were the main factors affecting the level of soil microbial community.

Conclusion Biochar addition could improve nitrogen retention and enzyme activities related to soil nitrogen cycle, improve soil microbial community structure, and further affect the transformation and removal of nitrogen in soil. Among different treatment groups, the application rate of 6 t/ha showed the most significant effect.

生物炭添加阻控河岸林地氮污染

Biochar addition to control nitrogen pollution in riparian forests