By: Ken Panchuk, PAg., Provincial Specialist Soils
Tall-stubble increases crop yields by 12 to 16 per cent during drier years by trapping snow for extra soil moisture. It also improves water use efficiency of the crop by 11 to 16 per cent. The total evapotranspiration remains the same when comparing tall-stubble to tilled stubble. However, the improvement is that more of the available water is transpired through the crop for growth and yield and less moisture is lost by evaporation from the soil surface.
Using modern straight cut combine headers or stripper headers allows you to cut the stubble as high as is practical. This year’s crops are not that tall, so do the best you can to optimize the height of the stubble without causing header losses. You can then finely chop and uniformly spread the crop residues during the harvest operation, providing a uniform layer of residue to protect the soil surface. Tall-stubble collects the snow and traps it in place to supply additional subsoil moisture for the next crop, as shown in Photo 1.
Minimizing the tramping of the standing stubble during seeding is an important step in tall-stubble technology. Zero-till equipment with disc type openers or knife openers guided with GPS and between the row guidance systems helps minimize the damage to the standing stubble. Photo 2 shows canola growing between the stubble rows.
Early-harvested canola or flax tall-stubble also makes excellent fields for establishing winter cereals.