Grainswest - Fall 2021

Fall 2021 Grains West 18 FEATURE prevents it from running off the surface into the ditch.” Among a dozen other benefits of crop residue retention cited by Evans are better crop root penetration, blackening of light-coloured soils, faster soil warming, increased protection against soil disease and decreased soil compaction. He estimated farmers save about $72 per acre in fertilizer input when straw is left on the field. Apart from the immediate agronomic effects of crop residue removal, there is the big picture to consider. SOIL STUDIES “Studies in Australia, Europe and China, as well as closer to home at the University of Alberta and by Agriculture Agri-Food Canada, confirm that removing straw reduces soil organic matter,” said Martin Entz, professor of cropping systems and natural systems agriculture at the University of Manitoba’s department of Plant Science. “It doesn’t have an immediate negative impact on the soil; rather, it is a process that can take years or decades.” In light of this downside, agronomists are studying the use of field practices that best maintain soil health and carbon levels in crop systems where the straw is removed. This includes the use of cover crops and the employment of strategic crop rotations. Such practices may allow farmers to support wheat straw initiatives such as those now under development in Alberta and Saskatchewan, which could in turn support Alberta’s trade prospects. “Being the first plant of its kind in North America to leverage our existing wheat straw supply to manufacture MDF is the kind of innovative investment we are seeking to attract to Alberta,” said Photo:Pixabay “It doesn’t have an immediate negative impact on the soil; rather, it is a process that can take years or decades.” —Martin Entz New straw fibre processing facilities to be built in Alberta and Saskatchewan will require a supply of the stuff. Although crop scientists are quick to list the many benefits of straw retention, some suggest there may be a good case for marketing it in certain cases.