Fertility management in viticulture

How to increase the level of organic matter in the soil, vitiforestry, etc...

Fertility management in viticultureHow to increase the level of organic matter in the soil, vitiforestry, etc...

1. Viticulture
2. Fertility management in viticulture

Technical articles - Productivity, Nutritional quality, Protection against insects and pests, Diseases

Deficiencies Targeted fertilisation Potassium Trace elements Soil regeneration NBSOIL

Soil health is a major factor in vineyard management. This page lists all the practices that can be used to improve it. For each technique mentioned, you will find a link to a more detailed article.

Amendments : green manures, mulching, prebiotics and liming

In agriculture, an amendment is an input that can be mineral(e.g. : lime) or organic(e.g. : peat, manure, RCW, vine shoots, etc.), the main function of which is to enrich the biological and physical quality of the soil.. They should be distinguished from fertilisers, which are intended to be used directly for crop growth, although some also enrich the soil by adding organic matter.

Green manures and mulch

All the information on soil cover in winegrowing can be accessed via the"Plant cover in winegrowing" portal, which lists the various cover and mulching practices, under or between the rows.

Prebiotics

Prebiotics are food substances, generally made up of bound sugars, which are thought to selectively promote the growth of certain bacteria. They can therefore be used in agriculture to stimulate the activity of soil micro-organisms. Their action specifically targets the bacteria and fungi involved in the root growth of the crops planted, thereby improving the structure and biological activity of the soil.

Their use in crop production remains poorly documented, with only a few pioneering agricultural suppliers offering fertilisers formulated with prebiotics.

Liming

Liming is the name given to the agricultural practice of adding calcium or calcium-magnesium amendments to soil to correct an excessively acid pH. Cultivated soil has a natural tendency to acidify as a result of its biological activity(particularly mineralisation), which leads to the production of organic acids. However, this same biological activity is reduced when the soil pH is too low, so the soil can be 'limed' to raise the pH value by neutralising the excess organic acids.

The addition of calcium also has a beneficial effect on soil structure and the availability of trace elements to plants. A soil's pH is generally considered to be optimal for agricultural production when it is close to 6.5.

In viticulture, it is advisable to carry out preventive liming before planting a new plot, and then to check the pH regularly(every 3 to 5 years) to carry out maintenance liming if necessary..

Fertilisers : Organic and mineral

Fertilisers include all the organic and mineral substances that are applied to an agricultural plot to provide crops with the nutrients they need to grow. These elements are most oftennitrogen (N) phosphorus (P) and potassium (K). Fertilisers are classified as simple, binary or ternary, depending on whether they contain just one, two or three of these nutrients. A distinction is made between mineral fertilisers (produced synthetically or by drilling) and organic fertilisers of animal or plant origin.

Vineyard needs and optimum inputs

Nitrogen

The vine ' s nitrogen requirements are relatively low, since the grape bunches are often the only exports over the entire growing season and do not contain an excessively high concentration of nitrogen. It is estimated that 12 to 30 units of nitrogen are exported annually per hectare via the grape harvest.. As a result, yield targets have a strong influence on the amount of nitrogen to be applied: the Comité Français d'Étude et de Développement de la Fertilisation Raisonnée (COMIFER) estimates these requirements at between 30 and 60 kg N/ha for yields of 6 to 10 T/ha and 60 to 90 kg N/ha for yields of 10 to 25 T/ha..

Phosphorus

In viticulture, phosphorus deficiencies are rare, whether in the plant or in the soil. This element migrates very slowly through the soil, and adding it has very little immediate effect; on the other hand, there is a risk ofeutrophication in aquatic environments in the event of run-off. In such cases, it is advisable to apply phosphorus only as a basic fertiliser, at the time of planting..

Potassium

The potassium plays an important role in maintaining the pH of plant cells. It can be applied as a basic or maintenance fertiliser if analyses (of soil and petiole) indicate low levels.

Various tools and tests to control fertilisation

Soil analysis is therefore an essential aspect of fertilisation management. In viticulture, the most common analyses are as follows :

• Visual observations of the soil, using soil pits or augers.
• Visual observations at plant level, to study vigour or track down any symptoms of deficiencies or toxicity.
• Soil analysis.
• Leaf diagnostics.

Other less widespread techniques also exist, such as Gérard DUCERF's bio-indicator plant method, on which the Soildiag analysis tool is based.

• Training in soil diagnosis using the recognition of bio-indicator plants by Gérard DUCERF, and field application of this diagnosis, videos produced by Ver de Terre Production.

Biostimulants

Biostimulants are defined by the European Commission as all "substances and micro-organisms that can stimulate natural processes to improve nutrient consumption and nutrient efficiency and crop quality.". They therefore cover a wide range of products of different kinds, which can be categorised as fertilisers(e.g. growth promoters) or soil improvers(e.g. : soil activators).

Agroforestry or Vitiforestry

Definition

Agroforestry is the combination of trees and crops or animals on the same plot of land, either on the edge or in the open field.

In viticulture, the term Vitiforestry is sometimes used to designate all the agroforestry practices applicable to mechanised winegrowing systems.

Impact on fertility

There are many benefits to these practices, some of which relate to fertility management. The root systems of trees planted in vineyards help to bring water up from the deep layers of the soil to the surface and increase soil porosity. In addition, agroforestry systems generally allow for the production of ramial fragmented wood, which can be used as mulch and organic fertiliser for the vines.

All the information you need to know about vitiforestry can be found on the"Agroforestry in viticulture" portal.

• Feedback on a vitiforestry project at the Pierre-Jean VILLA estate (69).
• Video of a training course on planting trees in vineyard plots, with Alain CANET and Ver de terre production.

To find out more

• Regenerate your soils" training course by Alfred Gässler in the form of a video produced by Ver de Terre production.
• Presentation by Mickaël Hedde,"Soil fertility" at a market gardening & arboriculture technical day : Soil conservation (2020).