Soil physical properties and residue cover were measured in a three-year study of broadleaf crop rotations under conventional, minimum and zero-tillage at Melfort and Tisdale. Rotations were canola-wheat-barley-barley, canola-barley-pea-wheat, and canola-pea-flax-barley. Tillage levels included conventional tillage (fall and spring tilled), minimum tillage (spring tilled) and no-till (no preseeding tillage). Soil moisture was higher at seeding depth (0-5 cm) under no-tillage compared to conventional tillage. Soil temperatures were generally lower in no-tillage than conventional tillage in April, and variability was generally higher in conventional compared to no-tillage due to heating during the day and cooling at night. Variability in soil temperature for conventional and no-tillage was similar in mid May. In general, tillage and rotation did not significantly affect infiltration measured with saturated soil cores and a single-ring infiltrometer, though statistical error for both methods was high. Crop residue decomposed at similar rates in broadleaf and cereal canopies. Residue cover was lower under conventional tillage compared to zero tillage, and may not be sufficient for erosion control following years of low productivity for broadleaf crops at Tisdale.
Soil physical properties and residue cover were measured in a three-year study of input levels and cropping diversity at Scott, Saskatchewan. Input levels were organic, reduced and high, while cropping-diversity levels were low diversity wheat, diverse annual and diverse annual perennial. The potential for soil erosion during the period near spring seeding was significantly higher in organic and high input compared to reduced systems. This was attributed to higher frequency of tillage in organic and high input compared to reduced systems. In general, tillage increased the proportion of soil aggregates (< 0.5 mm diameter) which are prone to wind erosion, and decreased the amount of crop residue at the surface. Cropping systems with high frequency of tillage and low production of residue have the highest potential for erosion. Fall rye in diverse annual systems significantly decreased the amount of bare soil and potential for erosion in the spring.