Managing living mulch (cover crops) to improve soil health (including nutrient cycling) and encourage natural enemies

在果园果树上使用活覆盖物正受到越来越多的关注。通过将生物保护(为主要天敌提供避难所)、碳封存、养分循环和土壤健康(微生物学)结合起来，活的地膜有可能显著改善以前的杂草管理。然而，如何最大限度地发挥这些覆盖作物的潜在效益，同时将管理它们所需的努力降至最低，目前尚不清楚。我们将评估果园中单一栽培和混合栽培的几种候选覆盖植物，特别强调在营养循环和对植物生长重要的关键微生物群(例如促进植物生长的根际细菌、菌根真菌)的丰富方面的保护、生物控制和土壤健康。我们还将考虑在桌面草莓生产中使用覆盖作物，主要目标是保护性生物防治。尽管未来四年的确切研究内容可能会因新的研究发现而改变，但将包括以下几个方面：(1)覆盖作物的种群动态与土壤养分枯竭和气候条件的关系；这将对覆盖作物管理、碳汇和果树养分的有效性产生影响；(2)评估苹果和草莓主要天敌的动态与作物发育阶段和害虫动态的关系；我们还将描述与植物相关的挥发性物质，以了解观察到的天敌种群动态的性质，以及植物阻止或吸引特定生物的能力。(3)土壤微生物区系的特征，重点是那些与营养循环有关的微生物和一般有益生物；在这一领域，我们将特别关注这些微生物(及其活动)与植物/树木生长的关系。(4)除了实验室研究外，还将种植一个新的苹果园，专门研究候选植物用作活的覆盖物。

The use of living mulch in orchard fruit crops is receiving increasing attention. Living mulch has the potential to significantly improve previous weed management by incorporating conservation biocontrol (providing refuges for key natural enemies), carbon sequestration, nutrient cycling, and soil health (microbiology). However, how to maximize the potential benefits of these cover crops while minimising the efforts required to manage them is not yet clear. We will evaluate several candidate cover plant species in monoculture and mixtures in orchards, with specific emphasis on conservation biocontrol and soil health in terms of nutrient cycling and abundance of key microbial groups important to plant growth (e.g. plant growth promoting rhizobacteria, mycorrhizal fungi). We will also consider the use of cover crops for table-top strawberry production with the primary objective on conservation biocontrol. Although the exact research contents over the four-year period may change in response to emerging novel research findings, the following aspects will be covered:(1) Population dynamics of cover crops in relation to depletion of soil nutrients and climatic conditions; this will have implications on cover crop management, carbon sequestration, and availability of nutrients to fruit crops (2) Assess dynamics of key natural enemies for apple and strawberry pests in relation to crop development stage and pest dynamics; we will also characterise plant-associated volatiles to understand the nature of the observed population dynamics of natural enemies and the ability of plants to deter or attract specific organisms.(3) Characterising soil microbiota with the emphasis on those microbes associated with nutrient cycling and general beneficial organisms; in this area, we will pay particular attention to the relationship of these microbes (and their activities) with plant/tree growth.(4) In addition to laboratory research, a new apple orchard will be planted, specifically designed to study the use of candidate plant species as living mulch.