Green manure
Legumes that fix nitrogen and feed the soil.
Green manure is a central nitrogen source in organic viticulture. Legumes (faba beans, lupins, clovers, vetch) are sown to fix atmospheric nitrogen and, when incorporated or managed as cover, make it available to the vine.
Beyond nitrogen, it produces biomass that improves soil structure and life, and suppresses weeds in the inter-row. The choice of mix and termination timing determine how much nitrogen is released and when.
Effort
Low to medium — annual sowing and incorporation.
Cost
Low — seed and one pass.
Time to result
1–2 seasons for nitrogen to show in the vine.
What it works against
Effectiveness by problem — click through for detail and metrics.
Nutrition & fertility
Biological nitrogen fixation by legumes is the main renewable, organically-authorised nitrogen source.
Time horizon: 1–2 seasons
What to measure for this pairing
Weed control
A dense legume cover occupies the inter-row and suppresses weeds by competition and shading.
Time horizon: 1 season
What to measure for this pairing
How it works
Bacteria in legume roots fix atmospheric nitrogen; as the biomass decomposes, that nitrogen mineralises and becomes available to the vine.
How to apply
- 1Choose the legume mix for the nitrogen need.
- 2Sow in autumn to use the moisture.
- 3Terminate/incorporate in spring before competition.
- 4Log sowing and incorporation per plot.
What to measure
Frequently asked
How much nitrogen does green manure supply?
It depends on mix, biomass and conditions, but well-established legumes supply a significant part of the vine’s nitrogen needs.
Doesn’t it compete with the vine for water?
It can, if unmanaged. Terminating/incorporating before the dry period and leaving residue as cover reduces competition.
Related reading
Related means
How GrapeFlow helps
Apply and document this means by plot, with an audit-ready history for certification.
Soil & leaf analyses
Soil and leaf results by plot and year, in the same place you log applications — so you can see what the amendment changed.
Electronic field notebook (Portugal)
In Portugal, all operations — weeding, green manure, biocontrol — logged by plot and date, ready for organic certification.
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