Authors
Duncan MacEwan, CA Davis, Richard Howitt
Description
Crop rotation systems have played a key role in agricultural production for thousands of years, dating back to the biennial grain-fallow rotations employed by the Ancient Greeks. Agronomists have researched the science and physical characteristics of rotations in terms of breaking pest and disease cycles, managing soil fertility, reducing weed populations, and managing water availability. Agricultural economists have noted the importance of these factors in terms of the effects on profits and cited smoothing input use and mitigation of risk as important determinants of aggregate, farm-wide rotations. Fundamentally, rotations are rooted in intertemporal spillover effects between crops, the economic consequences of which depend on relative input and output prices. However, researchers usually model agricultural production as a static process, treating production activities as independent, and omit the true underlying dynamics of rotations. Modeling the changes in agricultural production as a result of environmental and natural resource policies, specifically where agricultural biodiversity is important, can only be modeled on a micro, field-level, basis taking into account rotational interdependencies.