Tillage and crop rotation effects on the yield of corn, soybean, and wheat in eastern Canada
Citation
Morrison, M.J., Cober, E.R., Gregorich, E.G., Voldeng, H.D., Ma, B., Topp, G.C. (2017). Tillage and crop rotation effects on the yield of corn, soybean, and wheat in eastern Canada. Canadian Journal of Plant Science, [online] 98(1), 183-191. http://dx.doi.org/10.1139/cjps-2016-0407
Plain language summary
In a farmers field tillage or ploughing is the practice of mechanically turning over the soil. Farmers in Canada are changing the way they practice tillage by reducing it, or even eliminating it. When tillage is eliminated this is called no-tillage. Reducing tillage lowers the costs of fuel needed for farm operations and can influence soil nutrients, diseases and the amount of water it can retain. Crop rotation is the practice of changing the crop grown in a field on an annual basis. Monoculture refers to the conditions when a crop is not changed from year to year, but is grown continuously without rotation. The most common crop rotation in eastern Canada uses corn, soybean and wheat. We did an experiment comparing a 3-year rotation of corn, soybean and wheat to monoculture corn, soybean and wheat. We compared no-tillage to conventional tillage; ploughing in the fall and cultivating in the spring. Over the 15 years that we did the experiment, corn plots grown with conventional tillage had 20% greater yield than when grown under no- tillage. There were no differences in soybean and wheat yields between the tillage types. Wheat yielded 22% more and corn yielded 8% more when grown in the corn-soybean-wheat rotation than when grown in just monoculture but there were no yield differences in soybean crops grown in monoculture. Future work will examine the effects of crop rotation and tillage type on plant diseases.
Abstract
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.