31 July 2001
Managing weeds and slumped soils after rape
Rape that was badly flooded out and subsequently had little grass weed control has been disced in good conditions and rolled with plenty of moisture present. How long will I need to wait before I have to accept that there will be a need to plough to put the high seed return to the bottom? These dead lifeless flooded areas – subsoil or shakerator?
Ideally, rape stubbles should be left undisturbed to allow the seed to chit on the soil surface. The same applies to black-grass (not so for brome – see previous answer).
I presume that the cultivation you have done was a shallow one – hopefully with moisture present, you will get a chit quite rapidly.
By ploughing down rape, however, you encourage the seed to go dormant and it will re-emerge in later years. But if you dont get a chit then ploughing will help control black-grass.
The bare patches may well need subsoiling if the soil has slumped and there is poor structure – dont mind how you do it but make sure that the depth is correct, just below the normal cultivation depth. You dont need to scrape the top of the drains thats called mole ploughing!