When not to direct drill? Some years, it is wet but the harvest still has to be got in and the result is ruts. They may have to be cultivated out but it is as well to remember that direct drilled soils are less likely to rut because of the resilience of organic matter and a “blocky” structure which distorts less under load, even when wet. Also, some soils naturally form pans which may need to be cultivated out. Last reason is to bury weed seeds – but try not to plough them up next year. Rotational cultivations may be the answer with a progression to long term direct drilling.
Persist with direct drilling next year wherever possible to help build up organic matter. (Actually it is more a question of avoiding the oxidation of organic matter from conventional cultivations which could be 35% pa while direct drilling will be as little as 10% or less.)
Bill Butterworth, Land Research Ltd. August 18