Cover crops (living mulches) in the tree row of organic orchards: why and how? (BIOFRUITNET Practice Abstract)

Summary

After establishing living mulch, tree row maintenance is cheaper and, depending on the species, can provide different ecosystem services (e.g., nitrogen fixation), functional biodiversity (e.g., nectar source for pollinators, habitat for beneficials), soil conservation, etc... The cultivation of secondary cash crops as living mulch can be a source of additional income.
Practical recommendation
• Prepare the establishment of the living mulch with summer tillage, then prepare the seedbed in early autumn.
• Prefer short, low-lying perennial species with high capacity of soil coverage in irrigated orchards.
• For perennial species, sow or plant living mulches in autumn to favour their establishment. During the first season, one or two mowings and possibly manual weed control may be necessary. After establishment, if necessary, mow once a year to maintain a moderate plant height.
• Among the perennial living mulching species adapted to orchards in different pedo-climatic conditions: yarrow (Achillea millefolium, Picture 1), wild strawberries (Fragaria vesca), peppermint (Mentha piperita), lady’s mantle (Alchemilla vulgaris, Picture 2), crawling thymes (Thymus spp.), mouse-ear hawkweed (Pilosella officinarum), caucasian crosswort (Phuopsis stylosa, Picture 3), creeping cinquefoil (Potentilla reptans) and white bedstraw (Galium album).
• For rainfed orchards or those with a high risk of vole damage, favour the sandwich system (Tschabold, 2009) or the cultivation of annual species (vegetables, annual clover, etc.).
• When selecting the species, favour local ecotypes better adapted to pedo-climatic conditions.