Yield and profit comparison of diversified versus conventional crop rotation systems in South Dakota

Diversified crop rotations with no-till management are considered fundamental to sustainable agroecosystems; however, associated uncertainty in economic returns may hinder farmers’ decisions to adopt these practices. The objectives of this study were to compare economic performance (gross revenue, net revenue, and production cost) among various low-input diversified versus conventional crop rotations. The experiment was initiated in the fall of 2000 with winter wheat (Triticum aestivum L.) planting and planting of remaining crops in the spring of 2001 near Brookings, SD. Economic analysis was performed from data collected during the fifth complete 4-year crop rotational cycle (2017–2020) of six crop rotations: (1) 4-year corn (Zea mays L.)-soybean [Glycine max L. (Merr.)]-spring wheat-sunflower (Helianthus annus L.) (CSSwSf), (2) 4 year corn-soybean-spring wheat-pea (Pisum sativum L.) (CSSwP), (3) 4-year corn-pea-winter wheat-soybean (CPWwS), (4) 4-year corn-oat (Avena sativa L.)-winter wheat-soybean (COWwS), (5) 2-year corn-soybean (CS), and (6) continuous corn (CCC, treatment initiated in 2017). Corn yield in CSSwP rotation, where corn followed peas, was higher (p < 0.05) by 20%, 25%, 45%, and 89%, compared to CPWwS, CSSwSf, CS, and CCC rotations, respectively. Similarly, soybean yield following winter wheat was significantly higher by 16%–38% in COWwS and 13%–38% in CPWwS compared to CSSwP, CSSwSf, and CS. Overall, diversified crop rotations improved both corn and soybean yield and net revenue compared to 2-year CS and monoculture CCC rotations. Moreover, 4-year diversified systems, specifically COWwS, CPWwS, and CSSwP, demonstrated economic resilience by maintaining stable production costs.