State Key Laboratory of Soil and Sustainable Agriculture, Institute of Soil Science, Chinese Academy of Sciences, Nanjing 210008, China; University of Chinese Academy of Sciences, Beijing 100049, China.
National Engineering and Technology Research Center for Red Soil Improvement, Jiangxi Institute of Red Soil, Nanchang 331717, China.
Sci Total Environ. 2022 Mar 10;811:152342. doi: 10.1016/j.scitotenv.2021.152342. Epub 2021 Dec 15.
Unbalanced fertilization of nutritional elements is a potential threat to environmental quality and agricultural productivity in acid soil. Harnessing keystone taxa in soil microbiome represents a promising strategy to enhance crop productivity as well as reducing the adverse environmental effects of fertilizers, with the goal of agricultural sustainability. However, there is a lack of information on which and how soil microbial keystone taxa contribute to sustainable crop productivity in acid soil. Here, we examined soil microbial communities (including bacteria, fungi, and archaea) and soil nutrients, and the mineral nutrition and yield of maize subjected to different inorganic and organic fertilization treatments over 35 years in acid soil. The application of organic fertilizer alone or in combination with inorganic fertilizers sustained high maize yield when compared with the other fertilization treatments. Microbial abundances and community structures rather than their alpha diversities explained the main variation in maize yield among different treatments. Sixteen soil keystone taxa (a fungal operational taxonomic unit and 15 bacterial operational taxonomic units) were identified from the microbial co-occurrence network. Among them, five keystone taxa (in Hypocreales, Bryobacter, Solirubrobacterales, Thermomicrobiales, and Roseiflexaceae) contributed to high maize yield through increasing phosphorus flow and inhibiting toxic aluminum and manganese flow from soils to plants. However, the remaining eleven keystone taxa (in Conexibacter, Acidothermus, Ktedonobacteraceae, Deltaproteobacteria, Actinobacteria, Elsterales, Ktedonobacterales, and WPS-2) exerted the opposite effects. As a result, maize productivity varied among different fertilization treatments because of the altered maize mineral element flows by microbial keystone taxa. We conclude that microbial keystone taxa drive crop productivity through shifting aboveground-belowground mineral element flows in acid soil. This study highlights the importance of microbial keystone taxa for sustainable crop productivity in acid soil and provides deep insights into the relationships between soil microbial keystone taxa, crop mineral nutrition, and productivity.
营养元素的不平衡施肥是酸性土壤中环境质量和农业生产力的潜在威胁。利用土壤微生物组中的关键分类群来提高作物生产力并减少肥料对环境的不利影响，是实现农业可持续性的一种有前途的策略。然而，关于哪些土壤微生物关键分类群以及它们如何有助于酸性土壤中可持续的作物生产力，我们知之甚少。在这里，我们研究了土壤微生物群落（包括细菌、真菌和古菌）和土壤养分，以及在酸性土壤中经过 35 年的不同无机和有机施肥处理后，玉米的矿物营养和产量。与其他施肥处理相比，单独施用有机肥或与无机肥结合施用可维持较高的玉米产量。微生物丰度和群落结构而不是它们的α多样性解释了不同处理之间玉米产量的主要变化。从微生物共现网络中鉴定出 16 个土壤关键类群（一个真菌操作分类单元和 15 个细菌操作分类单元）。其中，有 5 个关键类群（Hypocreales、Bryobacter、Solirubrobacterales、Thermomicrobiales 和 Roseiflexaceae）通过增加磷流并抑制有毒的铝和锰从土壤流向植物，促进了玉米的高产。然而，其余的 11 个关键类群（Conexibacter、Acidothermus、Ktedonobacteraceae、Deltaproteobacteria、Actinobacteria、Elsterales、Ktedonobacterales 和 WPS-2）则产生了相反的效果。因此，由于微生物关键类群改变了玉米的矿物质元素流向，不同施肥处理下的玉米生产力也有所不同。我们得出的结论是，微生物关键类群通过改变酸性土壤中地上-地下矿物质元素的流动来驱动作物生产力。本研究强调了关键微生物类群在酸性土壤中可持续作物生产力中的重要性，并深入了解了土壤微生物关键类群、作物矿物质营养和生产力之间的关系。
