Crop diseases are kept in check as all crops have a 4-year span before they are planted back on the same piece of land, provided there are two different cereal crops used. Sclerotinia is the one disease that can carry across between pulses and oilseed crops so it has to be watched in wet years. Crop residues are easy to manage, as there is always a low residue crop, pulse or oilseed following a high residue crop, cereal. This helps avoid large residue build up that may cause plugging problems with seeding equipment. It also protects the soil with enough residues to avoid erosion.
Soil fertility is enhanced with the inclusion of a pulse in the rotation.
It was once believed that disease would be worse in a direct seeded crop than in conventional till and that the disease would stay around on the field longer because the straw is decomposing at a slower rate. At Indian Head research station Dr. Karen Bailey showed that disease was definitely worse on a direct seeded field with no crop rotation. This was wheat on wheat and the tanspot and septoria were worse on the direct seeded field compared to the conventional till wheat on wheat stubble. When she looked at wheat on oilseed or pulse stubble, the degree of disease infestation was the same whether the field was direct seeded or in conventional tillage. If the year is wet and humid and ideal for disease growth we will see disease in our crops.