Submitted to: Renewable Agriculture and Food Systems
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/7/2018
Publication Date: 7/5/2018
Citation: Archer, D.W., Liebig, M.A., Tanaka, D.L., Pokharel, K.P. 2018. Crop diversity effects on productivity and economics: A Northern Great Plains case study. Renewable Agriculture and Food Systems. 1-8. https://doi.org/10.1017/S1742170518000261.
Interpretive Summary: Increasing crop diversity, growing more different crops in a rotation, has been proposed as a way to increase sustainability. But, if producers are going to grow more diverse rotations, they need to be profitable. In this study, five no-till cropping systems with varying levels of crop diversity were evaluated. Results showed that the least diverse small grain-fallow rotation was significantly less productive and less profitable ($80-83 per acre less) than either a five-year rotation or a dynamic rotation. Net returns tended to increase and relative economic risk tended to decrease as crop diversity increased from small grain-fallow and continuous spring wheat, to a three-year rotation, to a five-year rotation, and to the most diverse dynamic system. Results from this study suggest that more diverse rotations can maintain or increase crop productivity and enhance economic viability.
Technical Abstract: Increasing crop diversity has been proposed to increase the sustainability of cropping systems. If producers are to adopt these systems, they should also be economically viable. In this study conducted near Mandan, North Dakota, four no-till cropping systems with varying levels of crop diversity were evaluated over a 12 year period to quantify system effect on crop productivity, input use, production costs, and economic risks and returns. Cropping system treatments included a small grain – fallow rotation (SG-Fallow) and a continuous spring wheat (Triticum aestivum L.) rotation (Cont SW) as baseline low-diversity rotations, a small grain-winter wheat (Triticum aestivum L.)-sunflower (Helianthus annuus L.) rotation (SG-WW-Sun), a five year rotation (Five Year), and a dynamic rotation (Dynamic). The SG-Fallow rotation was significantly less productive and less profitable on average than the other rotations, as measured by gross returns and net returns, respectively. However, SG-Fallow also used significantly less inputs than the other rotations. Production costs for the Cont SW and SG-WW-Sun rotations showed a significant increasing trend over time, while production costs for the Five Year rotation showed a significantly lower and slight decreasing trend over the period, with cost trends for the SG-Fallow and Dynamic rotations intermediate to these. Net returns tended to increase and relative economic risk tended to decrease as crop diversity increased from SG-Fallow and Cont SW, to SG-WW-Sun, Five Year, and the Dynamic system. Results from this study suggest that more diverse rotations can maintain or increase crop productivity and enhance economic viability.