Alternative to Weeding by Mulching or Sodding
Wool mulching or permanent grass cover with sedum as alternatives to chemical weeding, other than hoeing.
Context of implementation
The Auguste Clape estate, in brief
- Farmer's name: Olivier Clape.
- Department: Ardèche (07).
- UAA: Total: 8.9 ha. Vine: 8.9 ha. DEPHY cropping system: 8.9 ha.
- Workforce: 5 permanent FTE + 3 seasonal FTE.
- Types of wines / Grape varieties:
- Appellations:
- AOC St-Péray (10%).
- Cornas (62%).
- Côtes du Rhône and Vins de France (28%).
- Yield objectives:
- Local AOCs: 38-40 hl/ha.
- Côtes du Rhône & Wine de France: 40-45 hl/ha but rarely reached.
- Marketing channel: Private cellar.
- Other activities: None.
- Management mode:
- Majority Pruning goblet on stake.
- Density / spacing: 1.10*1.10 m on hillside, 2.40*1 m on plain.
- Soil type: granitic (85%), depth from 50 to 150 cm on slopes sometimes over 30%.
- Soil work by winch or hoe.
- Plots rather scattered within a small radius.
- Mulching and grass cover are reserved for small areas difficult to work (or only by hoe). This concerns some terraces of 3 different plots.
Origin of the practice
For several years, the practices of the estate had evolved towards less and less chemical weeding. However, some parts remained difficult to access especially for mechanical weeding (use of hoe only). Hence the choice to turn to innovative and local techniques.
Objectives
The objective of the winegrower in implementing this wool mulching or this permanent grass cover is to be able to do without either chemical weeding or soil work with the hoe in these hard-to-reach corners by other alternatives.
His expectations are also, for the part done with mulching, a better water behavior by limiting soil evaporation and retaining moisture after rain.
Regarding mulching, the wish is that it lasts at least 3 years without too much degradation. For grass cover, the longer the better as long as it is not too competitive for the vine.
Description of the practice
- Implementation of wool mulching from a local company that uses its waste to make this mulching.
Clarification on this price range which includes labor for installation: it is an extrapolation of the cost of the trial carried out on a very small surface and full coverage. Generally, mulching is laid only under the row, which reduces costs. Another supplier reference is Sotextho where the cost is about €1.80/m². This type of mulching has a lifespan of 3-4 years if not rolled or walked on. There are also mulches made from jute and hemp (Thorenap felt). Count on a thickness of 1400g/m² to have resistance equivalent to a thickness of 500g/m² of wool. With this mulch, the cost is around €13,000-14,000/ha (€1/m² excluding installation) for full coverage with a lifespan of 3-4 years.
- Implementation of a permanent grass cover of sedum, a small succulent plant naturally found on our rocks, little competitive and slow growing.
- Sowing done in autumn 2019 by broadcasting fragments of sedum collected near the plot.
Implementation steps
- Sedum: It is a small succulent plant, so the soil must be suitable for sedum, quite poor otherwise it will be colonized by other species. The best is to find it near the plots and make your own sowing by making many small fragments which will then be sown on previously worked soils, in autumn, at a rate of 200 to 300 g/m². It often quickly spreads by stolons.
- Wool mulching: We are only at the beginning of the test on this practice. To date, the important thing is to have a clean soil before laying and to cover the two strips well, put enough staples so that even over time the two strips do not separate to let some weeds through.
The practice within the farmer's strategy
Expected results
- Production objective: 35-38 hl/ha.
- Health objective: healthy harvest.
- Tolerance: some non-competitive grass.
- The areas targeted by the wool mulching and sedum methods are currently those maintained by Scenario No. 2, so the primary objective was the alternative to chemical herbicides.
- Reduction of hardship and working time in these corners only done with the hoe.
- In the future, see if mulching also allows better water behavior.
Results
| Level of satisfaction/performance | |
| Control of weeds with sedum | Hoped for better. |
| Cost of sedum | Very low so very good. |
| Time to implement sedum | Quick and simple. |
| Control of weeds with mulching | Very satisfactory so far. |
| Cost of mulching | Very high especially installation. |
| Time to implement mulching | Long and tedious but once
done WELL, it holds well. |
| Mechanization costs | None. |
| Fuel | None, except to bring the equipment by 4x4. |
The results are quite convincing for wool mulching, it remains to be seen how the wool will evolve over time, its degradation.
For sedum, establishment is slow and we do not yet have sufficient coverage to retain moisture, but it is slowly starting to monopolize the space.
Summary
Advantages
- Limits Erosion of soils.
- Improves water infiltration (sedum).
- Conserves moisture (mulching).
- Promotes soil life.
Limitations
- Progressive implementation on small areas.
- Installation cost (mulching) and use of staples.
- Possible competition with the vine (sedum).
Improvements planned
Wool mulching:
- Find biodegradable staples, see longer durability on mulching holding.
- Cost reduction (reduction of labor in the medium term).
Farmer's advice
- Mulching to be implemented only for small areas.
- Take time to staple well everywhere to prevent grass from coming out and the wind from lifting the mulch.
- Sedum: easy to install.
- Better to put whole mats rather than scattering many small pieces of sedum.
Opinion of Dephy network engineer Amandine FAURIAT (Chambre d’Agriculture de l’Ardèche)
Mulching
To date the practice is quite new, the objectives are met in terms of weed control over 2 years, it will be necessary to wait and see in the future the behavior of the vine and the degradation of the material. The other objective is also to observe whether there is better behavior of vines mulched regarding water stress. To date, no noticeable differences between the different parts.
Sedum
This small plant has already proven itself on the terroirs of Condrieu and Côte Rôtie a bit further north from us. Today it seems to establish well on the terraces where Olivier installed it. In the future, we still need to assess if it does not bring too strong competition to the vine.
What the farmer retains
“It is always interesting to test other solutions. There will never be a perfect solution but rather several to combine and adapt. Very nice surprise for wool mulching, it retains moisture very well. Still need to reduce the cost of raw material if several winegrowers or market gardeners (very interesting I think) also get involved.”
Appendices
- Remarkable Practices Sheet from the DEPHY network, Alternative to weeding by mulching or grass cover
- Work of the Chambre d’Agriculture du Rhône on the subject: https://extranet-rhone.chambres-agriculture.fr/actualites/toutes-les-actualites/detail-de-lactualite/actualites/lenherbement-peu-concurrentiel-des-vignes-de-fortes-pentes/
