Vole activity surveys predict damage to cover‐cropped soybean plants

Abstract

Across the Midwestern United States, farmers have increasingly used winter cover crops in corn-soybean rotations to improve soil health. Although this practice has many benefits, it also can provide habitat for potential pest species, such as voles (Microtus pennsylvanicus and M. ochrogaster). Voles have been reported by farmers to damage soybean plants in fields which had recently been cover cropped, but little has been done to quantify levels of damage related to their abundance. We evaluated the relationship between vole sign and soybean plant damage to help farmers manage this unintended consequence of using cover crops. We counted the frequency of vole sign along transects in cover-cropped fields. In addition to vole sign, we considered influence of cover-crop density, distance to field edge, and presence of artificial raptor perches when fitting negative binomial generalised linear mixed models to predict amount of soybean plant damage. An additive model including all explanatory variables and factors best explained variation in vole damage. Number of burrow entrances, presence of raptor perches, and cover-crop density were positively associated with soybean plant damage. Burrow entrances were most strongly associated with damage. Farmers can use frequency of burrow entrances to predict relative amounts of damage likely to be incurred; conditions in a field should be considered when deciding to manage for reduced vole populations before planting soybeans.

Killing time in cover crops? Artificial perches promote field use by raptors

“…Within our study area, deer mice ( Peromyscus maniculatus ) and prairie voles ( Microtus ochrogaster ) were commonly found in row‐crop agricultural fields (Berl, Flaherty, Danielson, Kellner, & Swihart, 2017), while additional species, such as meadow voles ( Microtus pennsylvanicus ) and northern short‐tailed shrews ( Blarina brevicauda ), were identified in adjacent permanent herbaceous habitats such as field borders or in‐field grass waterways (Prieur, 2019). Other potential prey items included avian prey (e.g., small passerines such as horned larks ( Eremophila alpestris ) and Lapland longspurs ( Calcarius lapponicus ) as well as larger species, such as killdeer ( Charadrius vociferus ) and blackbirds (Icteridae, personal observation).…”

“…Small mammal populations in our area were likely in a low phase during the 2 years of our study. A concurrent study (Prieur, 2019) observed low levels of vole damage to soybeans (0–14.1%) and had low trap success, while a regional study of northern harriers ( Circus hudsonius ), which are considered vole specialists in the Midwest, found relatively low levels of voles in harrier diets during the same time period (Zagorski, 2019).…”