贵州省马铃薯种植面积居全国第二位。然而,由于气候条件和不平衡施肥等因素,马铃薯田的土壤有机质消耗迅速,赤字很大,影响土壤生物功能和土壤肥力。生物炭和有机肥是补充外援有机质改善土壤质量的有效途径。然而,有机肥或生物炭与化肥配施条件下土壤肥力和微生物群落结构的差异及其相互关系尚不清楚。在这项研究中,常规施肥(NPK)三种处理,增加生物炭(NPKB)的应用,并增施有机肥(NPKO)研究了马铃薯根际土壤的特征,细菌群落组成,和多样性;分析这些因素对土壤综合肥力指数的影响;并探讨处理间FI对土壤肥力和细菌群落结构差异的直接和间接影响及其驱动因子。结果表明,土壤pH值,有效磷(AP),有效钾(AK),总氮(TN),有机碳(SOC),NPKB和NPKO处理的C/N比值明显高于NPK处理(P<0.05)。对于NPKO来说,土壤的FI是最大的,其次是NPKB,NPK治疗最少。从所有土壤样品中总共获得了8214辆ASV,属于26门,75班,165个订单,176个家庭和251属(不包括未鉴定的真菌)。变形杆菌,放线菌,氯氟虫是主要的门,占所有ASV的54.85%。与NPK和NPKB治疗相比,NPKO处理具有最高的细菌多样性和显著不同的分类单元的数量,土壤AN,AP,AK,SOC,TN,与细菌多样性指数显著相关(P<0.05)。此外,pH值,TN,和SOC是细菌分类群差异的显著影响因素(P<0.05),重要性为TN(70.59%)>SOC(49.42%)>pH(27.08%)。结构方程表明,与pH相关的土壤特性和细菌群落多样性是影响国际金融机构的直接途径,与土壤pH相关的土壤特性也可能通过影响细菌Shannon多样性而间接影响FI。这些结果表明,生物炭和有机肥添加处理之间的土壤肥力和细菌群落结构存在显着差异和相关性,pH和细菌群落多样性是影响FI的关键因子。特别是NPKO治疗对改善FI效果最好。考虑到土壤施肥和细菌功能群的影响,NPKO是土壤施肥协同效果最佳的推荐组合,也就是说,N150kg·hm-2+P2O5135kg·hm-2+K2O135kg·hm-2+有机肥6.6t·hm-2。
The potato planting area of Guizhou Province ranks second in China. However, due to factors such as climatic conditions and unbalanced fertilization, soil organic matter in potato fields is consumed rapidly and has a large deficit, which affects soil biological function and soil fertility. Biochar and organic fertilizer are effective ways to supplement foreign aid organic matter to improve soil quality. However, the differences in soil fertility and microbial community structure and their relationships under the conditions of organic fertilizer or biochar combined with chemical fertilizer are not clear. In this study, three treatments of conventional fertilization (NPK), increased application of biochar (NPKB), and increased application of organic fertilizer (NPKO) were set up to investigate the characteristics of potato rhizosphere soil, bacterial community composition, and diversity; to analyze the effects of these factors on the soil integrated fertility index; and to explore the direct and indirect effects of IFI on soil fertility and bacterial community structure differences between treatments and their driving factors. The results showed that soil pH, available phosphorus (AP), available potassium (AK), total nitrogen (TN), organic carbon (SOC), and C/N ratio were significantly higher in the NPKB and NPKO treatments than in the NPK treatment (P<0.05). Soil IFI was greatest for NPKO, followed by NPKB and least for the NPK treatment. A total of 8 214 ASVs were obtained from all the soil samples, belonging to 26 phyla, 75 classes, 165 orders, 176 families, and 251 genera (excluding unidentified fungi). Proteobacteria, Actinobacteria, and Chloroflexi were the dominant phyla, accounting for 54.85% of all ASVs. Compared to that in the NPK and NPKB treatments, the NPKO treatment had the highest bacterial diversity and number of significantly different taxa, and soil AN, AP, AK, SOC, TN, and IFI were significant correlates of bacterial diversity index (P<0.05). Additionally, pH, TN, and SOC were significant influencers of bacterial taxa differences (P<0.05), with importance ranked as TN (70.59%) > SOC (49.42%) > pH (27.08%). Structural equations suggested that pH-related soil properties and bacterial community diversity were the direct pathways influencing IFI, and soil pH-related soil characteristics could also indirectly affect IFI by affecting bacterial Shannon diversity. These results indicate that soil fertility and bacterial community structure were significantly different and correlated between the biochar and organic fertilizer addition treatments and that pH and bacterial community diversity were the key factors influencing IFI, with the NPKO treatment in particular having the best effect on improving IFI. Considering the effect of soil fertilization and the functional group of bacteria, NPKO is the recommended combination for the best synergistic effect of soil fertilization, that is, N 150 kg·hm-2+P2O5 135 kg·hm-2+K2O 135 kg·hm-2+organic fertilizer 6.6 t·hm-2.