Establishing Switchgrass with a Corn Companion Crop to Improve Economic Profitability

Establishing switchgrass (Panicum virgatum L.) usually takes 2 yr, and revenue is not typically generated from the land until the end of the second year. Much is already known about establishing switchgrass as a bioenergy or forage crop, but identifying additional methods of establishment that provide revenue during the planting year without negatively impacting long‐term stand density or biomass yield would better incentivize farmers to convert portions of land to growing switchgrass. A field experiment was conducted to evaluate the impact of companion corn (Zea mays L.) seeding rate (49, 59, and 69 ×103 seeds ha−1) and establishment year N fertilizer rate (0, 112, and 224 kg N ha−1) on corn yield, switchgrass stand density, second‐ and third‐year biomass production, and the net economic return over the 3‐yr establishment period. Switchgrass stand densities averaged 5 plants m−2 fewer when companion cropped with corn compared with switchgrass planted alone (25.9 plants m−2), but all treatments resulted in successful stands with at least 17 plants m−2. Net annual economic return over the 3‐yr establishment period was maximized under most price scenarios when switchgrass was companion cropped with corn fertilized with 112 or 224 kg N ha−1 during the establishment year. These results confirm that switchgrass can be established with corn to improve short‐term net economic returns without negatively affecting long‐term switchgrass stand health.