Data from: Ecological intensification and arbuscular mycorrhizas: a meta-analysis of tillage and cover crop effects

1. Reliance on ecosystem services instead of synthetic, non-renewable inputs is increasingly seen as key to achieving food security in an environmentally sustainable way. This process, known as ecological intensification, will depend in large part on enhancing below-ground biological interactions that facilitate resource use efficiency. Arbuscular mycorrhizas (AM), associations formed between the roots of most terrestrial plant species and a specialized group of soil fungi, provide valuable ecosystem services, but the full magnitude of these services may not be fully realized under conventional intensively-managed annual agricultural systems.

2. Here we use meta-analysis to assess how reducing soil disturbance and periods without roots in agricultural systems affects the formation of AM and the diversity and community composition of arbuscular mycorrhizal fungi (AMF). We compiled data from 54 field studies across five continents that measured effects of tillage and/or cover cropping on AMF colonization and/or communities and assessed effects of management and environmental factors on these responses.

3. Less intensive tillage and winter cover cropping similarly increased AMF colonization of summer annual cash crop roots by ~30%. The key variables influencing the change in AMF colonization were the type of cover crop or the type of alternative tillage, suggesting that farmers can optimize combinations of tillage and cover crops that most enhance AM formation, particularly with no-till systems and legume cover crops.

4. Richness of AMF taxa increased by 11% in low-intensity vs. conventional tillage regimes. Several studies showed changes in diversity and community composition of AMF with cover cropping, but these responses were not consistent.

5. Synthesis and applications. This meta-analysis indicates that less intensive tillage and cover cropping are both viable strategies for enhancing root colonization from indigenous arbuscular mycorrhizal fungi (AMF) across a wide range of soil types and cash crop species, and possibly also shifting AMF community structure, which could in turn increase biologically-based resource use in agricultural systems.

1. 相较于合成、不可再生的投入品，依托生态系统服务被日益视为以环境可持续方式实现粮食安全的核心路径。这一被称为生态强化（ecological intensification）的过程，在很大程度上依赖于强化地下生物互作，以提升资源利用效率。丛枝菌根（arbuscular mycorrhizas, AM）是多数陆生植物根系与一类特化土壤真菌形成的共生体，可提供极具价值的生态系统服务，但在传统集约化管理的一年生农业系统中，这些服务的全部潜力往往未能充分发挥。
2. 本研究采用元分析（meta-analysis）方法，评估农业系统中减少土壤扰动与无根系周期对丛枝菌根形成及丛枝菌根真菌（arbuscular mycorrhizal fungi, AMF）多样性与群落组成的影响。我们整合了全球五大洲共54项田间研究的数据，这些研究均测定了耕作方式和/或覆盖种植对AMF定殖率及/或群落的影响，并分析了管理与环境因子对这些响应的调控作用。
3. 轻简化耕作与冬季覆盖种植均可使一年生夏季经济作物根系的AMF定殖率提升约30%。影响AMF定殖率变化的关键变量为覆盖作物类型或替代耕作方式类型，这表明农户可通过优化耕作与覆盖种植的组合方案，最大程度促进丛枝菌根的形成，其中免耕系统与豆科覆盖作物的组合效果尤为突出。
4. 相较于传统耕作模式，轻简化耕作下AMF分类单元的丰富度提升了11%。多项研究表明，覆盖种植会改变AMF的多样性与群落组成，但这类响应并不具有一致性。
5. 综合与应用：本元分析结果表明，轻简化耕作与覆盖种植均为可行策略，可在多种土壤类型与经济作物种类中提升本土丛枝菌根真菌（AMF）对根系的定殖率，同时或可改变AMF的群落结构，进而提升农业系统中基于生物过程的资源利用效率。