Integrating cultural tools for weed management in irrigated soybean in Southern Alberta
Jayasekara, S. D.. 2022.
Abstract
Soybean [Glycine max (L.) Merr.] is an important legume crop in western Canada.
However, soybean exhibits delayed emergence and growth compared with many weeds in
this region, resulting in greater reliance on herbicides. A field experiment was established
near Lethbridge, Alberta, in 2020 and 2021 to determine how four cultural weed
management practices [soybean row spacing (23 cm vs. 69 cm), target plant density
(400,000 vs. 600,000 plants ha-1) cultivar (slender vs. bushy) and fall rye cover cropping
(with vs. without)] influenced soybean productivity and weed suppression. Overall,
narrow compared with wide rows increased the ability for soybean to compete with and
withstand competition from weeds. Increased target densities improved weed
suppression, while bushy cultivars played a supporting role. The fall rye cover crop had
inconsistent effects between years. Planting a bushy soybean cultivar in narrow rows at
higher densities could improve irrigated soybean productivity and weed suppression in
Alberta.
