Yield and Economic Performance of Crop Rotation Systems in South Dakota

Crop yield and economic profitability, both highly dependent on local crop management, soil characteristics, and weather conditions, are among the most influential factors to consider when considering a cropping system. The objective of this study was to compare the economic returns of three different 4-yr diverse crop rotations with that of a 2-yr traditional crop rotation in eastern South Dakota. The rotations included were (a) corn (Zea mays L.)–soybean [Glycine max (L.) Merr.]–spring wheat (Triticum aestivum L.)–pea (Pisum sativum L.) (CSSwP), (b) corn–pea–winter wheat–soybean (CPWwS), (c) corn–oat (Avena sativa L.)–winter wheat–soybean (COWwS), and (d) corn–soybean (CS). Results showed that total cost for the CS rotation was 7.2, 14.9, and 18.2% greater than the COWwS, CSSwP, and CPWwS rotations, respectively. Whereas CS rotation had comparable corn yield with CSSwP and COWwS rotations, its soybean yield ranked the lowest among all the rotations. When N fertilizer application fell below the level necessary to achieve for yield maximization, the CS rotation demonstrated a lack of resilience as indicated by a continual decline in economic returns over time. In comparison, the CSSwP rotation demonstrated high resilience to reduced N fertilizer application rate, and its net revenue was the highest among all rotations and surpassed the CS. Our results suggest that extending the traditional CS rotation to the more diversified CSSwP rotation could simultaneously reduce input costs and overreliance on N fertilizer