Behnke Gevan D, Kim Nakian, Zabaloy Maria C, Riggins Chance W, Rodriguez-Zas Sandra, Villamil Maria B
Department of Crop Sciences, University of Illinois, Urbana, IL 61801, USA.
Centro de Recursos Naturales Renovables de la Zona Semiárida (CERZOS, UNS-CONICET), Departamento de Agronomía, Universidad Nacional del Sur, Bahia Blanca B8000, Argentina.
Microorganisms. 2021 Jun 8;9(6):1244. doi: 10.3390/microorganisms9061244.
Recent advancements in agricultural metagenomics allow for characterizing microbial indicators of soil health brought on by changes in management decisions, which ultimately affect the soil environment. Field-scale studies investigating the microbial taxa from agricultural experiments are sparse, with none investigating the long-term effect of crop rotation and tillage on microbial indicator species. Therefore, our goal was to determine the effect of rotations (continuous corn, CCC; continuous soybean, SSS; and each phase of a corn-soybean rotation, Cs and Sc) and tillage (no-till, NT; and chisel tillage, T) on the soil microbial community composition following 20 years of management. We found that crop rotation and tillage influence the soil environment by altering key soil properties, such as pH and soil organic matter (SOM). Monoculture corn lowered pH compared to SSS (5.9 vs. 6.9, respectively) but increased SOM (5.4% vs. 4.6%, respectively). Bacterial indicator microbes were categorized into two groups: SOM dependent and acidophile vs. N adverse and neutrophile. Fungi preferred the CCC rotation, characterized by low pH. Archaeal indicators were mainly ammonia oxidizers with species occupying niches at contrasting pHs. Numerous indicator microbes are involved with N cycling due to the fertilizer-rich environment, prone to aquatic or gaseous losses.
农业宏基因组学的最新进展使得能够对因管理决策变化而产生的土壤健康微生物指标进行表征，这些决策最终会影响土壤环境。关于农业实验中微生物分类群的田间尺度研究很少，没有一项研究调查轮作和耕作对微生物指示物种的长期影响。因此，我们的目标是确定轮作（连续种植玉米，CCC；连续种植大豆，SSS；以及玉米-大豆轮作的每个阶段，Cs和Sc）和耕作（免耕，NT；和凿耕，T）在经过20年管理后对土壤微生物群落组成的影响。我们发现，轮作和耕作通过改变关键土壤性质（如pH值和土壤有机质（SOM））来影响土壤环境。与SSS相比，单一栽培玉米降低了pH值（分别为5.9和6.9），但增加了SOM（分别为5.4%和4.6%）。细菌指示微生物分为两组：依赖SOM的嗜酸性微生物与对氮不利的嗜中性微生物。真菌更喜欢以低pH值为特征的CCC轮作。古菌指标主要是氨氧化菌，其物种在不同pH值的生态位中占据一席之地。由于富含肥料的环境容易造成水生或气态损失，许多指示微生物都参与了氮循环。
