These include crops such as barley, oat, wheat, rye, canola, mustard species ... They may compete with weeds, and thus reduce their vigour, or they may have allelopathic properties. Cereal cover crops ...

It also has been shown to provide natural, allelopathic suppression ... soil types and conditions where other cereal grains may fail. Optimal soil pH for rye is 5.0-7.0, but it will tolerate ...