“Nurse” Crops Can Boost Yields
Recent years have seen increased attention on the health of the soil used in potato production, and attempts to bring potatoes into longer rotations with other crops.
In an article recently published by country-guide.ca, Ralph Pearce illustrates how seed companies are promoting soybeans or corn as rotational options, while others, such as McCain, have developed one- and two-year multi-species cover crop blends, to help boost organic matter and limit erosion.
Sheldon Hann, a biologist with Agriculture and Agri-Food Canada (AAFC) in Fredericton, is quoted as saying there is a direct correlation between organic matter and crop production — the higher the level, the higher the yield. The challenge across much of Eastern Canada is that some rotational crops such as soybeans and dry beans don’t add much residue to the soil. Aggressive tillage on sandier, porous soils with potato production in the Maritimes also makes it difficult to maintain organic matter.
That has prompted an interest in “nurse” crops planted along with potatoes. In 2015, Bernie Zebarth, one of Hann’s colleagues in Fredericton, began a multi-faceted project to find opportunities to lengthen rotations, improve soil health, improve yields and enhance biodiversity.
“In Zebarth’s study, one of his main findings was that a relatively small increase in tuber yield would be sufficient to justify the extra costs associated with growing the “nurse” crops. They would provide that extra protection of soil and when you plant potatoes, you have nearly a month of bare soil, and the “nurse” crop is going to provide that cover, offer that interception and minimize soil erosion,” said Hahn.