Title: Impact of corn residue on yield of cool-season crops Author
Submitted to: Renewable Agriculture and Food Systems
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: August 8, 2013
Publication Date: N/A
Interpretive Summary: Cool soil temperatures can suppress crop growth, especially in no-till systems during wet springs. This study found that reducing the amount of corn residue on the soil surface can minimize this detrimental effect on crop yield. We reduced residue quantity by planting a lower density of corn. Grain yield of spring wheat and dry pea and forage yield of red clover was 10 to 18% higher with less corn residue. Furthermore, yield loss due to weed interference in spring wheat and red clover was less with lower quantity of residues. We can reduce the plant density of corn without losing yield by growing corn after dry pea. Dry pea synergistically improves corn physiology and resource use such that fewer plants are needed for optimal yields. Producers may be able to reduce the negative impact of corn residue on following crops by using synergistic crop sequences in their rotation. Producers are often hesitant to add alternative crops to their rotations because of possible economic penalties due to low crop value. We have found that corn yields are similar at lower crop densities when dry pea is the preceding crop rather than soybean. This benefit can save 25 to 35$ per acre due to lower seed costs. A second benefit is that crops following corn yield more when less corn residue is lying on the soil surface with no-till. Thus, producers can gain a second financial benefit from dry pea synergism to corn reducing the need for high density of corn plants. The benefits of crop diversity may exist even in years beyond the initial crop sequence.
Technical Abstract: Synergy between dry pea and corn can reduce the density of corn needed for optimum yield. Lower crop density may accrue an additional benefit, as after-harvest residues of corn lying on the soil surface can reduce yield of crops planted the next year. This study evaluated impact of corn residue levels on growth and yield of three cool-season crops in no-till. Corn was grown at two densities, 52,000 and 73,000 plants ha-1, leading to after-harvest residue levels designated as high and low residue. Residue quantity on the soil surface differed by 21%. Controls were included for each residue level by burying residue with tillage. Spring wheat, dry pea, and red clover were planted the following year. Grain yield of spring wheat and dry pea and forage yield of red clover were reduced 13 to 33% by residue on the soil surface. However, yield of cool-season crops were 10 to 18% higher in the low residue treatment compared with high residue. Furthermore, yield loss due to weed interference in spring wheat and red clover was greater with high residue. Of the three crops, spring wheat was the least affected by corn residue on the soil surface. One contributing factor to lower yield with high residue was reduced crop seedling establishment. Producers may be able to reduce the negative impact of corn residue on following crops by using synergistic crop sequences in the rotation.