Rapeseed regrowth and white clover cover crop valorisation through sheep grazing

Authors: Daniel Jamar, Christel Daniaux, Cyril Régibeau

Problem: The period between the rapeseed harvest and winter cereal sowing is too short to grow a summer cover crop. The regrowth of rapeseed can also be a problem, and therefore needs to be controlled following the rapeseed harvest. Moreover, carbon from the rapeseed crop residues returning to the soil need to be managed. To do so, there is often a need to increase soil nitrogen availability following the rapeseed crop.

Solution: Rapeseed is usually sown in August together with winter sensitive legumes (Alexandrian clover, lentils, field beans and peas) acting as companion plants limiting weed development. In our case, we add white clover (WC) to the seeds mixture as a winter persistent legume that will grow slowly under the rapeseed and other companion plants mixture. Due to the increase in light availability its growth will increase with the loss of the first rapeseed leaves reaching maturity. Within 2-3 weeks after the rapeseed harvest full ground cover will have been achieved by the WC and rapeseed regrowth mixture. Sheep grazing should then take place. The mix is a very good sheep feed and the incorporation of nitrogen from the sheep manure into the soil balance the carbon rich residues from the harvested rapeseed (maintaining the carbon:nitrogen ratio in the soil at low level).

zenodo.org: Rapeseed regrowth and white clover cover crop valorisation through sheep grazing