Soil nutrient supply in cultivated bush bean-potato intercropping grown in subarctic soil managed with agroforestry
Karagatzides, J.D., M.J. Wilton and L.J.S. Tsuji . 2021.
Abstract
To address food insecurity in northern Canada, some isolated communities started garden-
ing initiatives to reduce dependencies on expensive foods flown in to communities. From 2012 - 2014,
soils in northern Ontario James Bay lowlands were cultivated with bush beans and potatoes, grown
in sole and intercropping configurations, in an open field and an agroforestry system enclosed by
willow trees. The objective of this study was to compare the supply rates of 15 plant-available
nutrients in these soils using in situ ion exchange membranes. After three years of cultivation, the
agroforestry site had significantly greater supply of PO4, Ca, and Zn and these nutrients had positive
correlations with yield. By contrast, the open site had significantly greater supply of Mg, SO4, and
B; these nutrients, and Al, had negative correlations with yield. Whilst there were no differences
between sole and intercropping configurations, significantly greater supply of NO3, Ca, Cu, Fe, and
Zn occurred early in the growing season, compared to significantly greater supply of K, SO4, B, and
Al later in the season. Significantly greater yields have been harvested in the agroforestry site and it
is suspected that the presence of a willow shelterbelt improves the microclimate and plant-available
PO4, Ca, and Zn.
Key Words
nutrient supply rate; subarctic agriculture; agroforestry; bush bean; potato; northern agriculture management; ion exchange resins; PRS probes
