Bioenergy Cropping Systems for Food, Feed, Fuel, and Soil.

Crop production can meet multiple needs including food, livestock feed, and bioenergy or biofuels. Cropping systems can be developed to focus on meeting any one of these needs, or they can be developed to simultaneously meet multiple needs. In any case, these systems must also protect the soil resource which drives current and future productivity. The multi-functionality of cropping systems raises an overarching question, namely: How do we best allocate crop production among food, feed, fuel, and soil uses? A study was initiated at the USDA-ARS Northern Great Plains Research Laboratory, Mandan, ND in 2009 to help answer this question. The study looks at options for intensifying crop production (growing more grain and biomass) combined with options for intensifying crop utilization (using more of the grain and biomass for food, feed, fuel). Crop production options include moving from a low-intensity wheat (Triticum aestivum L.)-dry pea (Pisum sativum L.) rotation to a higher intensity wheat-pea-corn (Zea mays L.) rotation or a wheat-pea/cover crop rotation. Crop utilization options include moving from a low-intensity option of grain harvest only to higher intensity options of: harvesting wheat straw, harvesting all crop residues, and grazing all crop residues. Results for 2010 showed a significant reduction in wheat yield following corn if residue was grazed compared to wheat following pea with no residue harvest. Treatments had no effect on pea or corn yields. Net returns were highest for the wheat-pea-corn rotation due to relatively high corn prices and exceptionally high corn yields.