Heavily baked vegetable land is made free of bruises using trenches.
Couch grass does not penetrate deep into the soil with its rhizomes. you suffocate, when they reach deeper layers, z.B. when draining. However, the uppermost layer of soil, which is interspersed with couch grass, must be removed (about 25cm) come to the bottom of the Rigol. With this type of trenching, the previous second layer of soil comes to the top. It must be heavily enriched with humus.