NutritionWeed control

Green manure against weed control

The effectiveness, measured

60 /100

Time horizon: 1 season

Why it works

A dense legume cover occupies the inter-row and suppresses weeds by competition and shading.

What to measure for this pairing

Weed coverCover density

Why this problem matters

Under organic rules synthetic herbicides are prohibited, so under-row weed control becomes one of the biggest operating costs. Management is mechanical, physical and agronomic.

Mechanical weeding in the row, a competitive cover in the inter-row and mulch are the main levers. The challenge is to control competition for water and nutrients without over-tilling or damaging the vines.

Problem indicators

Mechanical weeding passesWeed cover in the row (%)Control cost per hectare

Certification & rules: The absence of herbicide is an absolute requirement of organic 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 meansWeeds

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.