NutritionNutrition & fertility

Green manure for nutrition & fertility

The effectiveness, measured

85 /100

Time horizon: 1–2 seasons

Why it works

Biological nitrogen fixation by legumes is the main renewable, organically-authorised nitrogen source.

What to measure for this pairing

Nitrogen fixed (kg N/ha)Bought fertiliser replaced

Why this problem matters

Without synthetic mineral fertilisers, organic nutrition is indirect: you feed the soil, and the soil feeds the vine. Nitrogen comes from legumes and organic matter, and mineralisation runs at the pace of soil biology.

That requires planning — green manures, authorised organic amendments and regular analyses — to balance vigour and yield without the excess that raises disease susceptibility. Organic nutrition is soil management, not a fertiliser bag.

Problem indicators

Organic nitrogen applied (kg N/ha)Soil organic matterLeaf / soil analysis

Certification & rules: Only authorised inputs; traceability of applications is required at certification.

How to apply the means

  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.

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.

Same means, other problems

Same problem, other meansNutrition

Related reading →Copper in organic viticulture: the limits, the maths and how to stay under them

How GrapeFlow helps

The proof organic certification demands — logged by plot and date.

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.