13 August 2001
Whats the best rotation for direct drilling?
What would be the most workable rotation in a direct-drilling situation?
We try to rotate white stubbles (cereals) with fragile stubbles that shatter (break crops) as much as possible.
That said, my favoured rotation is wheat, barley, oilseed rape, wheat, Pulse (spring, if possible).
In an ideal world we would not include barley in the rotation, but we have been having problems getting rape drilled after wheat.
We find if you are to direct drill the crop needs to be planted a week earlier than if you had ploughed or deep cultivated.
This is to do with the T sum of rape germination. It is usually about 100-120 day degrees, but when you no-till it seems to be about 140-150 day degrees. By going earlier, the soil is just that bit warmer and the crop has more time to catch up.
Another reason for going earlier is that slugs seem to be less of a problem in August than early September.
The reason for going for a spring sown bean crop is to give time to clean up dirty fields or rectify soil structure problems. Where the land is in good heart we would go for a more reliable winter bean crop.