Overview

Wheat is grown in almost every state in the continental United States. Here, we calculate indicators for all wheat production-including both winter wheat, which is planted in fall and harvested in spring, and spring wheat, including durum, which is planted in spring and harvested in summer. The type of wheat grown depends primarily on climate conditions. Across the U.S., wheat production acreage is greatest in the central plains, including Kansas, Texas, the Dakotas and Montana. The summary chart for wheat shows improvement in the 2010 to 2020 period compared to 1980 to 1990 for all indicators, with the greatest improvements in land use, irrigation water use and energy use (Figure 1.11.1). A summary of all indicators for wheat for reference years is shown in Table 1.11.1. Figure 1.11.1. Summary chart of indicators for wheat during 1980-2020 Data are presented in index form, where all indicators have been scaled by indicators averages for the period 1998-2002. A 0.1 point change is equal to a 10 percent difference. Index values allow for comparison of change across indicators with different units of measure. A smaller area represents improvement over time. Additional illustrations of wheat sustainability on a per acre basis and for total resource use are available in Appendix B, accessible from the Download Report link. 

Land Use

Land planted to wheat has steadily declined since 1980 (Figure 1.11.2), as has total production although at a slower rate (Figure 1.11.3). The land use efficiency indicator shows a modest improvement over time, reflecting increasing crop yields (Figure 1.11.4).

Energy Use Efficiency

Energy use efficiency for wheat improved somewhat in the early 2000s, following a level trend through the 1980s and 1990s, and again staying largely static since 2010 (Figure 1.11.5). A steady increase in no till adoption from 2000 through 2020 contributed to this improvement. Energy use per acre has increased during the years of this study (Figure B.41). There have been increases in nitrogen and phosphorous fertilizer use, which has offset the reductions in management energy (Figure B.42).

Greenhouse Gas Emissions

Greenhouse gas emissions per bushel of wheat are largely flat across time with some interannual variations (Figure 1.11.6). Emissions per acre have increased, particularly since 2010 (Figure B.43). This is largely driven by increasing nitrous oxide emissions because nitrogen fertilizer applications have increased across this time period (Figure B.44). The top four contributors for energy use and GHG emissions for wheat during 2010 to 2020 are listed in Table 1.11.2.

Irrigation Water Use Efficiency

Irrigation water use efficiency for wheat has improved over the study period (Figure 1.11.7), with a small reversal period in the 1990s followed by a steady improvement since 2000. Across the 2008, 2013 and 2018 Irrigation and Water Management Survey for wheat, the average irrigated harvested acreage was 6.7% of total harvested acres.

Soil Erosion

Soil erosion for wheat decreased markedly in the 1990s, and erosion estimates since 2000 have been steady at approximately 5 tons of soil loss per acre per year (Figure 1.11.8). Download Wheat Data