What is green manure?
Green manure is a natural agricultural practice that involves sowing pure grasses or a mix of grasses, which are then used to fertilise the soil. This fertilisation technique, indispensable in organic viticulture, is also called green manuring. It consists of burying plants capable of releasing previously absorbed nutrients into the soil. Green manure replaces the use of chemical fertilisers, providing the soil with large quantities of nitrogen.
What are the benefits of green manuring?
The benefits are numerous!
Besides being a natural fertilisation technique, it increases the amount of organic matter in the soil. It protects the soil from the erosive action of rain and wind by retaining water. It contributes to the control of weeds and pests. It facilitates the descent of the roots of cultivated plants and maintains micro elements such as iron, manganese, etc. on the surface. Finally, it facilitates biodiversity by encouraging the establishment of beneficial insects.
In viticulture, green fertilisation brings more organic substance to the soil, promoting balanced vine development.
Which herbs should be chosen for green manure in viticulture?
Ideally, a seed mix should be used, in order to obtain a balanced nutrient supply. The seed mix contains different species of plants belonging to the leguminous families, which provide nitrogen to the soil, grasses, which are rich in fibre and promote the formation of organic matter and humus, and cruciferous plants, which combat the establishment of dangerous soil pests.
When to carry out green manuring?
Green manure sowing in viticulture should be done in autumn, after the grape harvest. Before sowing, the vineyard must be properly prepared by removing weeds with a mulcher, improving soil oxygenation with a soil loosener, and preparing the seedbed with a depth of approximately 20 centimetres. After preparing the soil, the mixture is sown on moist soil to facilitate germination. At this point, rolling is carried out after working the soil thoroughly.