Historic wheat-yield trendlines in the southern Great Plains

Hard red winter wheat grown in the Great Plains accounts for ~40% of total U.S. wheat production, primarily used to make bread wheat flour. Because U.S. wheat is a principal human food grain and a major export product, increasing wheat yields has remained a priority to benefit U.S. farmers and to protect global food security. 

Since the 1950s, USDA scientists in Lincoln, NE, have coordinated the Hard Winter Wheat Regional Performance Nurseries (HWWRPN) to foster wheat yield improvement on behalf of public and private organizations located throughout the Great Plains. Using HWWRPN yield data collected from 1959 to 2024 in the southern Great Plains, trendlines for wheat improvement indicated that yields significantly increased by ~1.0% per year compared with the historic check variety “Kharkof.” On-farm gains were estimated at ~25 kg/ha/yr.

Notwithstanding, non-linear models provided the best overall fit to the 64-year datasets, revealing an upper plateau for relative grain yield starting in 2000 (Fig. 1A) and a more gradual levelling-off of on-farm yield best fit by a quadratic curve (Fig. 1B). It remains to be seen if new technological drivers in agricultural management paired with wheat-breeding gains will continue to maximize yields, especially in favorable environments, so that wheat yield improvement continues.