Potential of Shorter Corn/Alfalfa Rotations for Dairy Farms

Abstract

ABSTRACT On dairy farms in the Northeastern U.S., corn (Zea mays L.) and alfalfa (Medicago sativa L.) are often grown in long (4–5 year) rotations with each other, which can result in lower yields for both crops, increased fertilizer requirements, and increased pesticide use. The objective of this study was to evaluate the potential of shorter, three-year corn, three-year alfalfa rotations. Based on corn rootworm scouting, many (75%) third or fourth year corn fields are at risk from corn rootworm damage. Third and fourth year alfalfa fields had stand densities of 46 and 39 plants m−2, respectively, considerably lower than a commonly used rotational threshold of 53 plants m−2. Yields of alfalfa from fourth year fields were lower in two of the five fields. A partial budget economic analysis showed that for some operations, a three-year corn/three-year alfalfa rotation could be more profitable, need fewer insecticides and fertilizer inputs, and produce higher corn and alfalfa yields.