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 as well as protects the soil with enough residues to avoid erosion. Soil fertility is enhanced with the inclusion of a pulse in the rotation.
All weeds have a time of year or a specific climatic condition that they germinate and grow best.
If we always seed the field closest to home first and the field furthest away last we are selecting for specific weeds on these fields with our seeding habits. One of the best examples of this is Pigmy flower and Yellow Whitlow grass. May. If you always seed this field last, you have allowed these weed to go through their entire life cycle without any disturbance. Using a crop rotation to determine the time of seeding will vary the seeding time on each field as you rotate the crop on that field. Low residue stubble such as pulse or oilseed stubble should be seeded first as it will warm up sooner and will also dry out quicker due to the lack of residue covering the soil.