Tillage and crop rotation effects on the yield of corn, soybean, and wheat in eastern Canada
2017
Morrison, M.J. | Cober, E.R. | Gregorich, E.G. | Voldeng, H.D. | Ma, B. | Topp, G.C.
Farmers in Canada are adopting no-till (NT) production at a high frequency. Conventional tillage (CT) was compared to no till (NT) with corn (Zea mays L.), soybean [Glycine max (L.) Merr.], and wheat (Triticum aestivum L.) grown in monoculture or annual rotation in a long-term study established in Ottawa (1990). From 1996 to 2000, all plots reverted to NT conditions to study the transition effects from CT to NT. In transition from CT to NT, new-NT corn plots yielded significantly more than established-NT plots in the first year of transition only, while there were no transition effects for soybean or wheat. In 2001, the experiment was changed back to CT and NT. Over 15 yr of the tillage–rotation trial (2001–2015), CT corn yields were ∼20% higher than NT corn across all three rotations, but the differences were not significant at the 5% level (p values 0.11–0.15). Fertilizer was not incorporated in all NT corn and wheat crops and may have limited NT yields. Yields did not differ between CT and NT for either soybean or wheat in any of the rotations. Wheat and CT corn yielded 22% and 8% more, respectively, when grown in rotation than in monoculture. Soybean yield did not differ between rotation and monoculture. Crop order in the rotation (corn–soybean–wheat vs. corn–wheat–soybean) did not result in significant yield differences. An economic, agronomic, or environmental advantage will be needed to justify NT corn production in high-yielding environments of a humid continental agroecosystem.
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