These plants can offer diverse ecosystem services, such as managing disease and pests and improving soil quality.
Ecosystemic plants are cultivated plant species grown in the same agricultural parcel as cash crops, offering various ecosystem services. Their cultivation is not aimed at obtaining a directly marketable or consumable agricultural product (grain, root, forage…). Instead they help to support the biological processes of soil and plants, in the short, medium or long-term. There are many uses for these plants, a selection of which feature below.
Catch crops are sown at the end of summer to absorb nitrogen from the soil (residual or mineralised in autumn) and reduce nitrate leaching over winter. These intermediate crops are referred to as “nitrogen traps” (CIPAN in French). At the end of winter, catch crops release nitrogen when they decompose and return this nitrogen to the succeeding crop. These crops are known as “green manure” crops.
This action on the soil nitrogen cycle concerns numerous plant species and families, and has agricultural and environmental benefits for farmers. There are also regulatory advantages, as the law provides that all ground must be covered during the leaching period for Nitrate Vulnerable Zones (areas designated as being at risk from agricultural nitrate pollution). This applies to more than half of France's arable land area (SAU).
Service plants can contribute significantly to weed control. Uncontrollable adventitious flora can be replaced by a controllable cover plant, either by intercropping or in association with a plant companion or relay cropping.
Service plants provide weed management benefits in a number of ways:
Floral fallow plants help to enhance the diversity of pollinators (hymenoptera, butterflies, syrphids and other diptera). Pollinator abundance is strongly linked to floral species: bees favour phacelia, borage and white sweet-clover, and some bumblebees can reach red clover nectar. A complex floristic composition is more attractive and encourages pollinating entomofauna. This is particularly true when it covers a long flowering period which is compatible with the wild fauna and is managed to be adapted to pollinators (flowering stage reached, grinding after flowering).
Plant covers are favourable to earthworms who improve the physicochemical and biological properties of the soil, especially when the soil is not worked too much. This also has a positive effect on insect-eating and granivorous bird populations. On the other hand, in some circumstances intermediate crops can stimulate slug populations, and leguminous cover plants can encourage the development of voles.
Posted 09/20/2018 | Last modification 06/12/2020