The effect of straw on the establishment and growth of winter cereals

In two experiments differing in soil type and previous cropping history, direct drilling of winter cereals into chopped residues of straw from the previous crop resulted in a smaller yield than when the straw was burnt. Dry straw impeded the drill mechanism but when wetter straw allowed satisfactory seed sowing plant development was slowed, probably largely as a result of microbiological processes. Fewer tillers were then produced and the smaller grain yield was a consequence of fewer fertile ears per plant. Yields were not restricted so severely if the straw was rotovated or disced into the soil prior to drilling.