Yang Yingfen, Ye Chenghu, Zhang Wei, Zhu Xiaohong, Li Haohao, Yang Dehai, Ahmed Waqar, Zhao Zhengxiong
Yunnan Agricultural University, Kunming, Yunnan, China.
Yunnan Revert Medical and Biotechnology Co., Ltd., Kunming, Yunnan, China.
Front Plant Sci. 2023 Sep 15;14:1250669. doi: 10.3389/fpls.2023.1250669. eCollection 2023.
In agriculture, biochar (BC) and nitrogen (N) fertilizers are commonly used for improving soil fertility and crop productivity. However, it remains unclear how different levels of BC and N fertilizer affect soil fertility and crop productivity.
This study elucidates the impact of different application rates of BC (0, 600, and 1200 kg/ha) and N fertilizer (105 and 126 kg/ha) on biomass accumulation, soil microbial biomass of carbon (SMC) and nitrogen (SMN), and soil biochemical properties, including soil organic carbon (SOC), total nitrogen (TN), soil nitrate nitrogen (NO-N), ammonium nitrogen (NH-N), urease (UE), acid phosphatase (ACP), catalase (CAT), and sucrase (SC) of tobacco plants. In addition, a high throughput amplicon sequencing technique was adopted to investigate the effect of different application rates of BC/N on rhizosphere bacterial communities of tobacco plants.
The results confirm that high dosages of BC and N fertilizer (B1200N126) significantly enhance dry matter accumulation by 31.56% and 23.97% compared with control B0N105 and B0N126 under field conditions and 23.94% and 24.52% under pot experiment, respectively. The soil biochemical properties, SMC, and SMN significantly improved under the high application rate of BC and N fertilizer (B1200N126), while it negatively influenced the soil carbon/nitrogen ratio. Analysis of rhizosphere bacteriome through amplicon sequencing of 16S rRNA revealed that the structure, diversity, and composition of rhizosphere bacterial communities dramatically changed under different BC/N ratios. Proteobacteria, Bacteroidetes, Actinobacteria, Firmicutes, and Acidobacteria were highly abundant bacterial phyla in the rhizosphere of tobacco plants under different treatments. Co-occurrence network analysis displayed fewer negative correlations among rhizosphere bacterial communities under high dosages of biochar and nitrogen (B1200N126) than other treatments, which showed less competition for resources among microbes. In addition, a redundancy analysis further proved a significant positive correlation among SMC, SMN, soil biochemical properties, and high dosage of biochar and nitrogen (B1200N126).
Thus, we conclude that a high dosage of BC (1200 kg/ha) under a high application rate of N fertilizer (126 kg/ha) enhances the biomass accumulation of tobacco plants by improving the soil biochemical properties and activities of rhizosphere bacterial communities.
在农业中，生物炭（BC）和氮肥常用于提高土壤肥力和作物生产力。然而，不同水平的生物炭和氮肥如何影响土壤肥力和作物生产力仍不清楚。
本研究阐明了不同施用量的生物炭（0、600和1200 kg/公顷）和氮肥（105和126 kg/公顷）对烟草植株生物量积累、土壤微生物生物量碳（SMC）和氮（SMN）以及土壤生化特性的影响，这些特性包括土壤有机碳（SOC）、全氮（TN）、土壤硝态氮（NO₃-N）、铵态氮（NH₄-N）、脲酶（UE）、酸性磷酸酶（ACP）、过氧化氢酶（CAT）和蔗糖酶（SC）。此外，采用高通量扩增子测序技术研究不同BC/N施用量对烟草植株根际细菌群落的影响。
结果证实，在田间条件下，与对照B0N105和B0N126相比，高剂量的生物炭和氮肥（B1200N126）显著提高干物质积累，分别提高31.56%和23.97%；在盆栽试验中分别提高23.94%和24.52%。在高施用量的生物炭和氮肥（B1200N126）处理下，土壤生化特性、SMC和SMN显著改善，但对土壤碳氮比有负面影响。通过对16S rRNA进行扩增子测序分析根际细菌群落，发现不同BC/N比例下根际细菌群落的结构、多样性和组成发生了显著变化。在不同处理下，变形菌门、拟杆菌门、放线菌门、厚壁菌门和酸杆菌门是烟草植株根际中丰度较高的细菌门。共现网络分析显示，高剂量生物炭和氮肥（B1200N126）处理下根际细菌群落之间的负相关关系比其他处理少，这表明微生物之间对资源的竞争较少。此外，冗余分析进一步证明SMC、SMN、土壤生化特性与高剂量生物炭和氮肥（B1200N126）之间存在显著正相关。
因此，我们得出结论，在高施用量氮肥（126 kg/公顷）条件下，高剂量生物炭（1200 kg/公顷）通过改善土壤生化特性和根际细菌群落活性来提高烟草植株的生物量积累。
