By Ken Panchuk, PAg Provincial Specialist Soils, Regina
Tall stubble technology is primarily used in the Brown and Dark Brown soil zones, where shortage of moisture often limits the yield potential. Using modern straight cut combine headers or stripper headers allows the operator to cut the stubble as high as is practical. This year’s crops are not that tall, so increase your stubble height as much as possible without causing header loss. The crop residues are finely chopped and uniformly spread during the harvest operation, providing a uniform layer of residue to protect the soil surface. The tall stubble also collects the snow and traps it in place to add additional subsoil moisture for the next crop.
Tall stubble increases crop yields by 12 to 16 per cent during drier years by trapping snow for extra soil moisture and improves water use efficiency of the crop by 11 to 16 per cent. The total evapotranspiration (water lost due to evaporation from the surface plus crop water use – transpiration) 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.
Avoid unnecessary driving on tall stubble fields to keep as much of the stubble standing as possible, especially if winter cereals are planned for those fields. Zero-till equipment with disc or knife openers guided by GPS and between-the-row guidance systems also helps minimize the damage to the standing stubble.
The success of improved moisture conservation is improved water use efficiency and higher yields.