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

在果园水果作物中使用活覆盖物正受到越来越多的关注。活覆盖物有潜力显着改善以前的杂草管理，结合保护生物控制（为主要的天敌提供避难所），碳固存，养分循环和土壤健康（微生物学）。然而，如何最大限度地发挥这些覆盖作物的潜在效益，同时最大限度地减少管理这些作物所需的努力，目前尚不清楚。我们将评估几个候选覆盖植物物种在单一栽培和混合果园，特别强调保护生物控制和土壤健康方面的养分循环和丰富的关键微生物群体重要的植物生长（如植物生长促进根际细菌，菌根真菌）。我们还将考虑使用覆盖作物进行桌面草莓生产，主要目标是保护生物控制。虽然四年期间的确切研究内容可能会因新的研究结果而有所变化，但将涵盖以下几个方面：（1）与土壤养分消耗和气候条件有关的覆盖作物种群动态;这将对覆盖作物管理，碳固存，水果作物的养分供应（2）根据作物发育阶段和害虫动态，评估苹果和草莓害虫主要天敌的动态;我们亦会研究与植物有关的挥发物，以了解所观察到的天敌种群动态的性质，以及植物对特定生物的阻吓或吸引能力。(3)表征土壤微生物群，重点是与养分循环和一般有益生物相关的微生物;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果园，专门用于研究候选植物物种作为活覆盖物的使用。

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.