Hou Jianwei, Xing CunFang, Zhang Jun, Wang Zuhua, Liu Min, Duan Yu, Zhao Hui
Institute of Resources, Environment and Sustainable Development, Inner Mongolia Academy of Agricultural and Animal Husbandry Sciences, Hohhot, Inner Mongolia, China.
School of Agroforestry Engineering and Planning, Tongren University, Tongren, Guizhou, China.
Front Plant Sci. 2024 May 15;15:1389864. doi: 10.3389/fpls.2024.1389864. eCollection 2024.
The large-scale planting of potatoes leads to soil degradation, thus limiting the potato yield. An effective method of improving soil quality involves the combined application of biochar and organic fertilizer. However, the proportion of biochar and organic fertilizer at which potato yield can be improved, as well as the improvement mechanism, remain unclear.
A combined application experiment involving biochar (B) and organic fertilizer (O) with four concentration gradients was conducted using the equal carbon ratio method. On this basis, rhizosphere soil fertility, bacterial community composition, and bacterial diversity in potato crops, as well as the potato yield difference under different combined application ratios, were investigated. Then, the direct and indirect effects of these factors on potato yield were analyzed.
The results suggest that soil fertility was improved by the combined application of biochar and organic fertilizer, with the best effect being achieved at a ratio of B:O=1:2. The dominant bacterial communities in the potato rhizosphere included , , , , and . When compared to the control, the relative abundance and diversity index of soil bacteria were significantly improved by the treatment at B:O=1:2, which exerted a stronger effect on improving the relative abundance of beneficial bacteria. Soil available phosphorus (AP), soil pH (SpH), and soil organic carbon (SOC) explained 47.52% of the variation in bacterial composition. Among them, the main factor was the content of soil available nutrients, while SpH generated the weakest effect. The bacterial diversity index showed a significant positive correlation with soil AP, SOC, available potassium (AK), total nitrogen (TN), and C/N ratio, and a significant negative correlation with SpH. Bacterial diversity directly affected the potato yield, while soil fertility indirectly affected potato yield by influencing the soil bacterial diversity.
The combined application of biochar and organic fertilizer elevates potato yield mainly by improving the diversity of bacterial communities in potato rhizosphere soil, especially the combined application of biochar and organic fertilizer at a 1:2 ratio (biochar 0.66 t ha+organic fertilizer 4.46 t ha), which made the largest contribution to increasing potato yield.
马铃薯的大规模种植导致土壤退化，从而限制了马铃薯产量。一种改善土壤质量的有效方法是生物炭与有机肥的联合施用。然而，能提高马铃薯产量的生物炭与有机肥比例以及改善机制仍不明确。
采用等碳比法进行生物炭（B）和有机肥（O）四个浓度梯度的联合施用试验。在此基础上，研究了马铃薯作物根际土壤肥力、细菌群落组成和细菌多样性，以及不同联合施用比例下的马铃薯产量差异。然后，分析了这些因素对马铃薯产量的直接和间接影响。
结果表明，生物炭与有机肥联合施用提高了土壤肥力，以B:O = 1:2的比例效果最佳。马铃薯根际的优势细菌群落包括 、 、 、 和 。与对照相比，B:O = 1:2处理显著提高了土壤细菌的相对丰度和多样性指数，对提高有益细菌的相对丰度有更强的作用。土壤有效磷（AP）、土壤pH值（SpH）和土壤有机碳（SOC）解释了细菌组成变异的47.52%。其中，主要因素是土壤有效养分含量，而SpH的影响最弱。细菌多样性指数与土壤AP、SOC、速效钾（AK）、全氮（TN）和C/N比呈显著正相关，与SpH呈显著负相关。细菌多样性直接影响马铃薯产量，而土壤肥力通过影响土壤细菌多样性间接影响马铃薯产量。
生物炭与有机肥联合施用主要通过提高马铃薯根际土壤细菌群落多样性来提高马铃薯产量，尤其是生物炭与有机肥按1:2比例（生物炭0.66 t/ha +有机肥4.46 t/ha）联合施用对提高马铃薯产量贡献最大。
