Biochar treatment of peanut rhizosphere nitrogen-fixing bacteria

Biochar plays an important role in the agricultural production process, it can improve soil fertility, promote nutrient uptake and plant growth and development, however, the distribution status of biochar in the soil is an important factor affecting its function. For this reason, we used a greenhouse peanut pot experiment to set up four treatments: control (CK), concentrated biochar application near seeds (B1), relatively concentrated surface application of biochar (B2) and uniformly dispersed application of biochar (B3), to investigate the changes in peanut growth, root morphology, soil nutrient uptake and the structure of soil microbial communities by non-uniform application of biochar. The results showed that the addition of biochar significantly increased the N uptake of peanut aboveground and root system, and reduced the NO3--N and NH4+-N concentrations in soil compared with no biochar application. The B2 treatment significantly increased the net photosynthetic rate and aboveground dry matter weight, which increased by 196.85% and 53.96% compared with the control, respectively, while the B1 and B3 treatments showed the next highest effect; meanwhile, the addition of biochar treatment also At the same time, the addition of biochar treatment also promoted the development of the root system and the number of rhizomes. In terms of microbial and bacterial communities, the addition of biochar increased the number of nitrogen-fixing bacteria to a certain extent, while the relative abundance of soil bacterial communities did not differ much. In conclusion, biochar was able to promote plant growth and development in general, while non-homogenization significantly affected the growth and developmental effects of peanut, with the relatively concentrated surface-applied biochar treatments having the most pronounced effects on improving plant nutrient uptake and root tumor development.

生物炭（Biochar）在农业生产过程中发挥着关键作用，可提升土壤肥力、促进养分吸收与植物生长发育。然而，其在土壤中的分布状态是影响其功能发挥的核心因素。为此，本研究采用温室花生盆栽试验，设置4个处理：空白对照（CK）、种子附近集中施加生物炭（B1）、相对集中的表层施加生物炭（B2）以及均匀分散施加生物炭（B3），探究非均匀施用生物炭对花生生长、根系形态、土壤养分吸收及土壤微生物群落结构的影响。结果表明：与未施加生物炭的处理相比，施加生物炭可显著提升花生地上部与根系的氮素吸收量，并降低土壤中硝态氮（NO₃⁻-N）与铵态氮（NH₄⁺-N）的浓度。其中B2处理可显著提升花生净光合速率与地上部干物质重量，较对照分别提升196.85%与53.96%，B1与B3处理的效果次之；同时，施加生物炭可促进根系发育与根瘤数量增长。在微生物与细菌群落方面，施加生物炭可在一定程度上增加固氮菌的数量，但土壤细菌群落的相对丰度并未出现显著差异。综上，整体而言生物炭可促进植物生长发育，而非均匀施用方式会显著影响花生的生长效果，其中相对集中的表层施加生物炭处理在提升植物养分吸收与根系发育方面效果最为显著。