College of Horticulture Science and Technology, Hebei Normal University of Science and Technology/Hebei Key Laboratory of Horticultural Germplasm Excavation and Innovative Utilization, Qinhuangdao 066004, Hebei, China.
Ying Yong Sheng Tai Xue Bao. 2024 Mar 18;35(3):713-720. doi: 10.13287/j.1001-9332.202403.015.
The problem of soil barrier caused by excessive accumulation of nitrogen is common in continuous cropping soil of facility agriculture. To investigate the modulating effects of biochar amendment on soil nitrogen transformation in greenhouse continuous cropping systems, we conducted a pot experiment with two treatments, no biochar addition (CK) and 5% biochar addition (mass ratio). We analyzed the effects of biochar addition on soil microbial community structure, abundances of genes functioning in nitrogen cycling, root growth and nitrogen metabolism-related genes expressions of cucumber seedlings. The results showed that biochar addition significantly increased plant height, root dry mass, total root length, root surface area, and root volume of cucumber seedlings. Rhizosphere environment was improved, which enhanced root nitrogen absorption by inducing the up-regulation of genes expressions related to plant nitrogen metabolism. Biochar addition significantly increased soil microbial biomass nitrogen, nitrate nitrogen, and nitrite nitrogen contents. The abundances of bacteria that involved in nitrogen metabolism, including Proteobacteria, Cyanobacteria, and (soil nitrogen-fixing bacteria), were also significantly improved in the soil. The abundances of genes functioning in soil nitrification and nitrogen assimilation reduction, and the activities of enzymes involved in nitrogen metabolisms such as hydroxylamine dehydrogenase, nitronate monooxygenase, carbonic anhydrase were increased. In summary, biochar addition improved soil physicochemical properties and microbial community, and affected soil nitrogen cycling through promoting nitrification and nitrogen assimilation. Finally, nitrogen adsorption capacity and growth of cucumber plant was increased.
设施农业连作土壤中氮素积累过量导致土壤板结问题较为普遍。为研究生物炭改良对温室连作土壤氮素转化的调控作用，采用盆栽试验，设置不添加生物炭（CK）和添加 5%生物炭（质量比）2 个处理，分析生物炭添加对黄瓜幼苗生长、氮代谢相关基因表达及土壤氮素转化功能基因丰度和微生物群落结构的影响。结果表明，生物炭添加显著增加了黄瓜株高、根干质量、总根长、根表面积和根体积。改善了根际环境，通过诱导与植物氮代谢相关的基因表达上调，增强了根系对氮的吸收。生物炭添加显著增加了土壤微生物生物量氮、硝态氮和亚硝态氮含量。参与氮代谢的细菌（如变形菌门、蓝细菌门和固氮菌门）丰度也显著提高。土壤硝化和氮同化还原功能相关基因丰度以及参与氮代谢的酶（如羟胺脱氢酶、亚硝态单加氧酶、碳酸酐酶）活性增加。综上所述，生物炭添加改善了土壤理化性质和微生物群落，通过促进硝化和氮同化来影响土壤氮循环，最终提高了氮的吸附能力和黄瓜植株的生长。
