Nutrition

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.

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

  1. 1Choose the legume mix for the nitrogen need.
  2. 2Sow in autumn to use the moisture.
  3. 3Terminate/incorporate in spring before competition.
  4. 4Log sowing and incorporation per plot.

What to measure

Estimated nitrogen fixed (kg N/ha)Biomass producedBought organic fertiliser replaced

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.

Fertilisation plan & analyses

Per-plot needs, organic amendments applied and soil and leaf analyses in one place.

Electronic field notebook

All operations — weeding, green manure, biocontrol — logged by plot and date, ready for organic certification.