Practicing Total Grass Cover in Vineyards
From Triple Performance
Total grassing in vineyard consists of replacing weed control with the maintenance of a herbaceous cover on the vineyard row, while inter-row grassing is already practiced. As a result, grassing is present over the entire surface of the vineyard plot.
Presentation
Description of the technique
Total grassing covers a wide range of situations given:
- The diversity of possible grassings: spontaneous or sown.
- The diversity of management methods (frequency, mowing height).
Total grassing is feasible in certain situations:
- Vineyards of the Atlantic facade.
- Deep soils.
- Controlled production objective.
- Vigorous plots.
In other cases, under-row grassing can be combined with practices in the inter-row less competitive for the vine such as mechanical weeding or temporary grassing.
Establishment
- Most plots at least 3 years old can be grassed and the choice of species planted, which can be mixed, must be considered according to the pedoclimatic situation and the expected behavior of the cover (competition, longevity, drought resistance).
- It is preferable to sow in autumn to facilitate cover establishment, without the need for fertilization in the open as the risk of increasing the turf vigor is too high. Sowing is generally done as a service.
Maintenance
- Maintenance must be careful the first year to ensure good turf establishment.
- Tractor passes in poor conditions should be avoided.
- Maintenance is done by mowing (3 to 5 times per year). Maintenance of the vineyard row can be done by mechanical (see Mechanical weeding of the inter-rows), thermal or chemical methods.
- The vineyard row can also be left in Controlled Natural Grassing (CNG).
Renewal
It depends on the species chosen and can be renewed every 5 years or even every 8-10 years, depending on its cleanliness condition.
Application
- Most plots can be grassed, except those with shallow soils suffering from significant water stress and non-mechanizable plots (steep slopes for example) which do not allow classic mowing mechanization.
- The increase in water and nitrogen stress is not sustainable in all vineyards under all climates.
- Regulatory evolution encourages the use of alternative techniques to chemical weeding.
Services provided
Regulation and weed management: Sowing species selected for their ability to quickly cover the soil allows to avoid the development of more troublesome weeds. However, covers evolve year by year and this effect may not be very durable.
Effects on the sustainability of the cropping system
Environmental criteria
- The effect on air and water quality is positive because grassing the plot allows to eliminate the use of herbicides to weed the vine row and the row and limits the transfer of phytosanitary products.
- The effect on fossil resource consumption can be improved because mowing interventions under the row are both more frequent and more energy-consuming than using a weeding boom.
Agronomic criteria
- Productivity: Total grassing of the vineyard always has a marked impact on productivity, the competition of cover crops compared to the vine being generally proportional to the ground area occupied. This yield decrease can be partially compensated after several years of establishment depending on the vine roots' ability to develop deeper.
- Production quality: There is no effect for an equivalent production objective. Depending on the production goal, perceived quality depends on the harvest quantity and berry concentration. With total grassing, maturity can be slightly higher and nitrogen nutrition of the berries lower.
- Soil fertility: Soil cover provides protection of the soil surface against rain and thus helps to limit runoff and soil erosion. Grassing is also a source of organic matter and has a decompacting effect of the root system, improving structural stability, porosity, and soil permeability.
- Water stress: Depending on soil type and species planted, grassing can induce water competition in the vineyard. If this is visually concerning, a light defoliation can be considered. For more information, see the IFV article on grassing and hydro-nitrogen stress management.
- Functional biodiversity: Grassing allows to create an ecological niche for beneficial insects, such as typhlodromus.
- Vigor: Grassing causes water-nitrogen competition which manifests among other things by a reduction in vine vigor. For more information, see the IFV research report on the effect of sown grassing on vine vigor.
- Must nitrogen content: Nitrogen competition causes a decrease in nitrogen content of musts. It can be corrected by localized soil applications under the row (for example 50 kg/ha ammonium nitrate under the row in early May), by foliar nitrogen spraying around veraison, or by adding fermentation activators on musts. For more information, see the IFV article on grassing and hydro-nitrogen stress management, as well as the video on the impact of under-row maintenance on must nitrogen.
Economic criteria
- Mechanization costs: Maintenance of grassing over the entire surface requires specific equipment (sowing, mowing), more expensive than a weeding boom.
See here an example of the cost of managing vineyard grassing[2] :
- Margin: Depends on the number of annual mowing interventions and work rate (working speed). The impact on yield can affect income and thus margin.
Social criteria
Working time devoted to mowing can be significant depending on the equipment chosen and the mowing frequency required.
For more information
- La minute vignevin: vineyard grassing
- -IFV, Multimedia, 2018
- Impact of under-row maintenance on must nitrogen
- -IFV, Multimedia, 2011
- Effect of sown grassing on vine vigor and fruit production
- -Serrano E., Dufourcq T., David N. IFV, Technical brochure
- Permanent grassing of the vine
- -IFV, Website
- Vines: grassing for living soils
- -Assaoui S. Multimedia, 2015
- Vineyard grassing: impacts and research avenues?
- -VignevinFrance, Multimedia, 2018
Appendices
Est complémentaire des leviers
Est incompatible avec les techniques
Contribue à
S'applique aux cultures suivantes
- ↑ vignevin-occitanie.com http://www.vignevin-occitanie.com/fiches-pratiques/enherbement-permanent/
- ↑ IFV, vignevin-occitanie.com - Practical sheets Permanent grassing http://www.vignevin-occitanie.com/fiches-pratiques/enherbement-permanent/
