Corn and soybean yields and returns are greater in rotations with wheat

Abstract

Simple rotations containing only corn (Zea mays L.) and/or soybean (Glycine max L.) dominate landscapes despite agronomic, soil health, and environmental benefits associated with diversification. We hypothesize that inclusion of wheat (Triticum aestivum L.) in corn-soybean (CS) rotations increases yield and net returns and that this benefit is becoming larger over time. Yields from rotation-tillage trials located near Elora and Ridgetown, ON, Canada, respectively, were used to investigate the yield and return effects of diversifying CS rotation using wheat with/without red clover (Trifolium pratense L). At Elora, wheat inclusion increased rate of yield increase in corn and soybean over 36 yr. During the latter 16 yr, adding wheat to CS rotation increased conventional tillage (CT) 1st and 2nd-year corn yields (with red clover) by 0.43 Mg ha −1 (4.2%) and 0.98 Mg ha −1 (11.8%), respectively, no-till 1st and 2nd-year corn yields (no red clover) by 0.78 Mg ha −1 (9.9%) and 0.45 Mg ha −1 (5.3%), respectively, and 1st-year soybean yield by 0.34 Mg ha −1 (11.8%). At Elora, net returns in the 4-yr wheat-containing rotations were 10% greater compared to the CS rotation. Similar corn and soybean yield responses including wheat in 2 or 3 yr rotations also occurred at the greater-yielding Ridgetown trial, however net returns were not increased relative to the CS rotation. Inclusion of wheat in CS rotation once every 4-5 yr may provide the optimal balance between accruing higher net returns from corn and soybean while minimizing direct net revenue reductions associated with wheat.

Agronomic and economic performance of 26‐year corn–soybean rotation affected by tillage and fertilization in eastern Canada

“…Janovicek et al. (2021) reported a corn yield reduction of 0.16 Mg ha −1 for each 4‐yr rotation during the latter 16 yr after conversion of a silt loam soil from fall chisel plow to NT. Worldwide, the negative effect of NT in cool and humid climates was found to be largest in corn, whereas oilseed like soybean was rather insensitive (Pittelkow et al., 2015) due to its large capacity to compensate for a poor establishment (Vega et al., 2000).…”

“…In southwestern Ontario, Drury et al (2012) obtained 11% lower yield in corn with NT than MP 10-12 yr after establishment of tillage treatment on a clay loam in a winter wheat (Triticum aestivum L.)-corn-soybean rotation. Janovicek et al (2021) reported a corn yield reduction of 0.16 Mg ha −1 for each 4-yr rotation during the latter 16 yr after conversion of a silt loam soil from fall chisel plow to NT. Worldwide, the negative effect of NT in cool and humid climates was found to be largest in corn, whereas oilseed like soybean was rather insensitive (Pittelkow et al, 2015) due to its large capacity to compensate for a poor establishment (Vega et al, 2000).…”

Long‐term yield response of corn, wheat, and double‐crop soybean to tillage and N placement

“…(Sindelar et al, 2015;Wil-helm & Wortmann, 2004) compared with monocrop yields. Recent work by Janovicek et al (2021) also found that corn and soybean yields and returns may be improved in rotations including wheat. Although row crop rotation is often recommended for improved production, these rotations may be affected by other cultural practices, such as tillage.…”

Cover crops in a Wisconsin annual cropping system: Feasibility and yield effects

“…annual rotation is common (Stanger & Lauer, 2008). Adding a third crop, like winter wheat ( Triticum aestivum L.), to this rotation can enhance some benefits of crop rotation including increased yield of all three crops as well as spreading the labor requirements throughout the year (Janovicek et al., 2021; Marburger et al., 2015).…”