Organic farmers are not allowed to use any herbicides to control weeds, and must therefore pull up each individual plant arduously by hand. Broad-leaved dock (Rumex obtusifolius) is a problem weed on meadows and pastures. Livestock disdains it owing to its bitter taste, and it represents serious competition for space and nutrients for fodder plants.
On organic farms, elimination of the weed by hand with a dock weeder followed by the roots being carted away is the common if arduous method of control used. Agroscope is now testing two new methods which should make this time-consuming job easier:
- One is to heat the roots to a depth of around twelve centimetres with a mixture of hot water and steam at a temperature high enough to kill them off. At the same time this prevents the germination of dock seeds lying dormant in the soil.
- The other method is to uproot the plants by machine, the second step of the process being to separate the roots from the adherent soil.
The holes thus created can then be backfilled with the reclaimed topsoil. The farmer ends up getting what he most wants: a lovely weed-free meadow.