Agronomic and economic trade-offs of integrating camelina into the corn–soybean rotation

Corn (Zea mays L.) and soybean [Glycine max (L.) Merr.] account for much of the arable land in the Upper US Midwest during the summer. Land is left fallow in late autumn after harvest through early spring leaving valuable growing degree days unused. Temporal intensification is a concept that considers planting crops such as winter camelina (Camelina sativa L.) during these fallow periods. Winter camelina is a freeze-hardy winter annual oilseed that can provide an economic benefit to farmers the following spring. However, there are significant agronomic and economic trade-offs associated with integrating camelina into the corn–soybean rotation. The objectives were to assess the yield potential and seed quality of a corn–camelina–soybean rotation using (1) a range of corn hybrid maturities, (2) corn stover presence or absence, and (3) calculate the economic trade-offs compared with a typical corn–soybean rotation. This study was conducted over the 2019 and 2020 growing seasons at two locations in Minnesota. Corn and soybean seed yield was maximized in treatments where camelina performed poorly and vice versa. Late corn harvest and stover presence had a negative effect on camelina establishment and yield but were favorable to soybean production. Based on both the agronomic and economic analyses for the aggregated cropping system, treatments that began with 90- and 95-day relatively mature corn hybrids performed equally well, regardless of stover presence. This indicates there are multiple options to move forward with a corn–camelina–soybean cropping rotation.