A Half-Century of Yield Growth along the Forty-First Parallel of the Great Plains

Abstract

We examine a half-century of crop yield growth along an 800-mile transect in the U.S. Great Plains. The main contributors to growth were nonspecific technical change +53%, irrigation +26%, fertilizer +13%, and chemicals +10%. Environmental changes were small and had a minor impact. The wide range of agroclimatic conditions produced significant subregional deviations. Irrigation was important in the more arid and warmer areas of the west, while fertilizer and chemicals were more important in the humid east. Sensitivity to weather has increased in the rain-fed regions of the east, while it has decreased in irrigated regions of the west.