Soil bacterial community is associated with high potato production and minimal water use

In agriculture, water consumption for crop production represents 69% of all water use. Precision irrigation systems based on available soil water have been developed to improve crop production, reducing water use. Besides the improvements in irrigation management, a better resolution of the optimal water level is required, and revealing the impact of soil matric potential on the soil microbial community may help. Here, the effect of four soil matric potential treatments (-15 kPa, -25 kPa, -30 kPa, and -45 kPa) was evaluated on the soil microbial community across three potato cultivars and two soil types (silt and sand). The results confirmed the soil matric potential with -25 kPa as the optimal irrigation level, which promoted high potato production using the minimal water use. The irrigation levels affected the composition, predicted functionality, and ecological network of soil bacterial community. Water excess (-15 kPa) and deficit (-30 kPa, and -45 kPa) promoted an increase in microbial interaction and alpha-diversity. The results suggested higher Positive/Negative ratio for phyla Proteobacteria, Actinobacteria, and Acidobacteria in optimal irrigation level (-25 kPa) than other irrigation levels. Also, correlation analyses revealed an interesting association between the irrigation levels, potato production, and bacterial functionality, especially in carbon cycle (fixation and emission). Therefore, this study proposed important associations between the soil bacterial community and water management, focusing on high potato production and minimal water use. The advancement of this knowledge may lead to a more comprehensive assessment of the optimal irrigation levels of others crop production systems. Furthermore, the inclusion of biological mechanisms, especially microbial interactions, in agriculture studies has the potential to contribute to the development of water management practices conducive to both increasing crop yield and maintaining a sustainable soil environment.农业领域中，作物生产的耗水量占总用水量的69%。基于土壤有效含水量的精准灌溉系统已被开发，旨在提升作物产量并降低水资源消耗。除优化灌溉管理外，还需更精准地确定最优灌溉水平，而揭示土壤基质势（soil matric potential）对土壤微生物群落的影响或可提供助力。本研究针对四种土壤基质势处理（-15 kPa、-25 kPa、-30 kPa与-45 kPa），探究其对三个马铃薯品种、两种土壤类型（粉壤土与砂土）下土壤微生物群落的影响。研究结果证实，-25 kPa的土壤基质势为最优灌溉水平，可在实现最低水资源消耗的同时提升马铃薯产量。灌溉水平显著影响土壤细菌群落的组成、功能预测及生态网络。水分过剩（-15 kPa）与水分亏缺（-30 kPa、-45 kPa）均会增强微生物互作并提升α多样性（alpha-diversity）。研究结果显示，在最优灌溉水平（-25 kPa）下，变形菌门（Proteobacteria）、放线菌门（Actinobacteria）与酸杆菌门（Acidobacteria）的正负互作比例高于其他灌溉水平。此外，相关性分析揭示了灌溉水平、马铃薯产量与细菌功能之间值得关注的关联，尤其在碳循环（固碳与碳排放）过程中表现突出。综上，本研究明确了土壤细菌群落与水资源管理之间的重要关联，核心目标为实现马铃薯高产与水资源低耗。该研究成果可推动对其他作物生产系统最优灌溉水平的更全面评估。此外，在农业研究中纳入生物学机制（尤其是微生物互作），有望助力开发既有利于提升作物产量，又能维持土壤环境可持续性的水资源管理实践方案。