Biochars produced from different feedstocks and at different pyrolysis temperatures may have various chemical and physical properties, affecting their potential use as alternative microbial carrier materials. In this study, biochars were produced from pine wood and oak feedstocks at various temperatures (400°C, 500°C, 600°C, 700°C and 800°C), characterized, and assessed for their potential as carriers for Bradyrhizobium japonicum (CB1809) strain. The biochars were then stored at two different storage temperatures (28°C and 38°C) for up to 90 days. Furthermore, the study also explored the role of potentially ideal carriers as inoculants in the growth of Glycine max L. (soybean) under different moisture levels i.e., 55% water holding capacity (WHC) (D0), 30% WHC (D1) and, 15% WHC (D2) using a mixture of 50% garden soil and 50% sand. The results were compared to a control group (without inoculants) and a peat inoculant. Among all the materials derived from pine wood and oak, pine wood biochar pyrolyzed at 400℃ (P-BC400) exhibited the highest CFU count, with values of 10.34 and 9.74 Log 10 CFU g^− 1 after 90 days of storage at 28℃ and 38℃, respectively. This was notably higher compared to other biochars and peat carriers. Significant (p < 0.05) increases in plant properties: shoot and root dry biomass (174% and 367%), shoot and root length (89% and 85%), number of leaves (71%), membrane stability index (27%), relative water content (26%), and total chlorophyll (140%) were observed in plants treated with P-BC400 carrier inoculant compared to the control at D2; however, lower enrichment of δ¹³C (37%) and δ¹⁵N (108%) with highest number of root nodules (8.3 ± 1.26) and nitrogenase activity (0.869 ± 0.04) were observed under D2, as evident through PCA analysis, showing more nitrogen (N) fixation and photosynthetic activity. Overall, this experiment concluded that biochar pyrolyzed at lower temperatures, especially P-BC400, was the most suitable candidate for rhizobial inoculum and promoted soybean growth.

由不同原料和不同热解温度生产的生物炭可能具有不同的化学和物理特性，影响其作为替代微生物载体材料的潜在用途。在这项研究中，利用松木和橡木原料在不同温度（400°C、500°C、600°C、700°C 和 800°C）下生产生物炭，对其作为日本慢生根瘤菌载体的潜力进行了表征和评估(CB1809)菌株。然后将生物炭在两种不同的储存温度（28°C 和 38°C）下储存长达 90 天。此外，该研究还探讨了潜在理想载体作为接种剂在不同水分水平下（即 55% 持水能力 (WHC) (D0)、30% WHC (D1) 和，15% WHC (D2)，使用 50% 花园土壤和 50% 沙子的混合物。将结果与对照组（无接种剂）和泥炭接种剂进行比较。在所有源自松木和橡木的材料中，400℃热解的松木生物炭（P-BC400）表现出最高的CFU计数，在28℃和90天储存后，其值分别为10.34和9.74 Log 10 CFU g ^{− 1} 。分别为38℃。与其他生物炭和泥炭载体相比，这一数字明显更高。植物特性显着增加 ( p  < 0.05)：芽和根干生物量（174% 和 367%）、芽和根长度（89% 和 85%）、叶子数量（71%）、膜稳定性指数（27%） )、相对含水量 (26%) 和总叶绿素 (140%) 在 D2 时与对照相比，用 P-BC400 载体接种剂处理的植物中观察到；然而，通过 PCA 分析，在 D2 下观察到 δ ¹³ C (37%) 和 δ ¹⁵ N (108%)富集度较低，根瘤数量最高 (8.3 ± 1.26) 和固氮酶活性 (0.869 ± 0.04)，显示出更多的固氮（N）和光合作用活性。总体而言，该实验得出结论，在较低温度下热解的生物炭，尤其是 P-BC400，是最适合根瘤菌接种并促进大豆生长的候选物。