According to the USDA 2023 Irrigation and Water Management Survey, ~53 million acres of harvested cropland and pasture were irrigated in 2023.[1] The 2022 Census of Agriculture reports a total of ~301 million acres harvested.[2]
USDA NASS (2024) Census of Agriculture, 2023 Irrigation and Water Management Survey, Vol 3, AC-22-SS-1, Table 3. [Total acres irrigated in 2023 = 53,135,170. The most complete data on U.S. irrigation is from this 2023 Irrigation and Water Management Survey, which we use for most of the following stats. The acreage designated is land in farms which “consists primarily of agricultural land used for crops, pasture, or grazing. It also includes woodland and wasteland not actually under cultivation or used for pasture or grazing, provided it was part of the farm producer’s total operation.”]
USDA (2024) 2022 Census of Agriculture, United States, Vol 1, Part 51, Table 9, p. 14. [Total acres harvested in 2022 = 301,327,737]
The estimated amount of water applied (withdrawals) to all harvested cropland and pasture in 2023 was ~81 million acre-feet.[1]
This figure is less than the amount of withdrawals in 2018 and 2013.[2] However, while the government reports an overall decline in water use for irrigation since 1980,[3] in what is known as a paradox of irrigation efficiency, “reduced irrigation withdrawal and application requirements have led to higher consumptive irrigation water use (i.e., irrigation-derived water lost irretrievably to the atmosphere through crop evapotranspiration). This results in reductions in downstream water supply as crop irrigation is optimized for production.”[4] And consumption of water is more critical because it is permanently lost, affecting the available amount of the water supply.[5]
USDA NASS (2024) Census of Agriculture, 2023 Irrigation and Water Management Survey, Vol 3, AC-22-SS-1, Table 7. [Total acre-feet applied in 2023 = 81,005,833. The USDA surveys for amounts of water “applied” rather than “withdrawn.” We assume that applied water is essentially the same as water withdrawal. This figure does not account for water use on double-cropped acres.] [An acre-foot is a common way to measure water volume and use. It is the amount of water it takes to cover an acre of land one foot deep and equals 325,851 gallons. See, Appendix B-2.]
USDA NASS (2019) Census of Agriculture, 2018 Irrigation and Water Management Survey, Vol 3, AC-17-SS-1, Table 7. [~83.3 million acre-feet applied in 2018; ~88.5 million acre-feet applied in 2013.]
Ketchum, D., et al., (2023). Irrigation intensification impacts sustainability of streamflow in the Western United States. Communications Earth & Environment, 4(1), 479–8, p. 2. [“Trends in climate-normalized IWU (consumptive irrigation water use) and IWU in perennially irrigated areas further support the notion of the counterintuitive increase in water use accompanying increases in irrigation efficiency, despite reductions in irrigation water applications, and are consistent with previous work at smaller scales.” at p.4]
Water Footprint Calculator (2022) Water Use, Withdrawal and Consumption. https://www.watercalculator.org/footprint/water-use-withdrawal-consumption/
Crops primarily used for animal feed include corn, soybeans, alfalfa and other hay, sorghum, and pasture. These crops accounted for ~61% of all harvested irrigated acres in 2023.[1]
USDA NASS (2024) Census of Agriculture, 2023 Irrigation and Water Management Survey, Vol 3, AC-22-SS-1, Table 38. [Note that “If two or more crops were harvested from the same land during the year (double cropping), the acres were counted for each crop. Therefore, the total acres of all crops harvested could exceed the acres of cropland harvested.” Appendix B definition “Acres and quantity harvested”] [Corn includes corn for grain + silage; Alfalfa/Hay includes alfalfa haylage & other hay and haylage. For calculations see:
https://docs.google.com/spreadsheets/d/1D3nnEa6Uj_xFPCop10hfaLVRuhEPkEcoyWvpOmiBWSI/edit?gid=0#gid=0
The volume of water applied (withdrawals) to harvested corn, soybeans, alfalfa and other hay, sorghum, and pasture was ~53% of all irrigation water applied in the U.S.[1]
USDA NASS (2024) Census of Agriculture, 2023 Irrigation and Water Management Survey, Vol 3, AC-22-SS-1, Table 39. [Calculation: using the average acre-feet applied per acre (by crop) multiplied by the number of irrigated acres per crop. Total acre-feet applied includes extra irrigation for double-cropped acres. Corn includes corn for grain + silage; Alfalfa/Hay include alfalfa haylage & Other hay and haylage. For calculations see: https://docs.google.com/spreadsheets/d/1D3nnEa6Uj_xFPCop10hfaLVRuhEPkEcoyWvpOmiBWSI/edit?gid=0#gid=0
Nearly 70% of the water used to irrigate crops primarily grown for animal feed comes from groundwater wells.[1] Additional groundwater may be used from off-farm water suppliers which include commercial companies or community water systems.[2]
USDA NASS (2024) Census of Agriculture, 2023 Irrigation and Water Management Survey, Vol 3, AC-22-SS-1, Table 40. [see, https://docs.google.com/spreadsheets/d/1WdorJ_yO8yDr5OfgHw_zm7RczOtD5sQ-IBAfVjEvMss/edit?gid=0#gid=0
2023 Irrigation and Water Management Survey, definitions “Off-farm water supply,” p. B-5, Appendix B.
By far, the largest usage of irrigated water by volume is alfalfa and other types of hay, accounting for ~20% of all irrigated water applied.[1] Alfalfa, hay, and haylage are used solely for animal feed.[2]
Corn and corn silage account for ~14% of all irrigated water applied.[3]
USDA NASS (2024) Census of Agriculture, 2023 Irrigation and Water Management Survey, Vol 3, AC-22-SS-1, Table 39. [Acre-feet applied to alfalfa & other hay = 16,675,939 / 83,311,649 million total acre-feet applied in the U.S. = 20.02%]
We broadly estimate that ~95% of hay goes to animals raised for food, with ~5% going to horses.
Acre-feet applied to corn and corn silage = 11,651,650 / 83,311,649 million total acre-feet applied in the U.S. = 13.99%]
Using the USDA estimates of irrigated water applied to all crops in 2023, ~44% of all irrigation water goes to the share of major crops actually used for animal feed.[1,2] This is in line with a modeling study that covered a 13-year period of water withdrawals.[3]
Number irrigated acres multiplied by average acre-feet applied from Table 39 [USDA NASS (2024) Census of Agriculture, 2023 Irrigation and Water Management Survey]
For calculations, see, https://docs.google.com/spreadsheets/d/1RhN2c8wckzI9srLp6RrSpI42HbXEC2v5kPZoCt7MSNs/edit?gid=0#gid=0 [Percent of crops going to animal feed, see Total Feed Crops Share]
Ruess, P. J., et al., (2023). Irrigation by Crop in the Continental United States From 2008 to 2020. Water Resources Research, 59(2), Table 2. [Finding corn grain, alfalfa hay, sorghum, and soybeans accounted for ~44% of groundwater withdrawals, ~59% of surface water withdrawals, and ~42.5% of groundwater depletion. These values were averaged across the 13-year period, and the study did not include water withdrawals for pasture. It is unclear if the corn category included corn silage.]
As a broad estimate, about 50% of all irrigated water goes to the portion of crops specifically used for animal feed.
Along with the crops primarily used for animal feed, there are many additional crops that are partially used for animal feed. And there are additional animal feed usages of major crops that often go uncounted. Taken together, these secondary feed crops and additional uses undoubtedly add at least 6% to the 44% of irrigated water on crops primarily used for animal feed, and likely make animal feed 50% or more of all irrigated water withdrawal.
A partial listing of those secondary feed crops includes wheat, barley, cotton seed, canola, rye, sunflower seeds, and peanuts. Among the additional usages is the practice of using crops directly for forage, which would not show up in the USDA’s accounting of irrigated crops, since they are not considered “harvested.”
Water consumption by crops primarily used for feed – alfalfa and other hays and haylage, corn, corn silage, and soybeans – accounts for 43% of total national water consumption and 57% of water consumption from all crop irrigation. This is according to a 2020 report by a preeminent water research team.[1,2]
Remarkably, alfalfa hay (and haylage) and other hay (and haylage) accounts for 20% of total national water consumption.[3]
Water consumption has more impact than water withdrawals because consumption permanently withdraws water from its source. Consumed water is no longer available (does not return to the source) because it has evaporated, been transpired by plants, incorporated into products or crops, or consumed by people or livestock.[4,5]
Richter, B. D., et al., (2020). Water scarcity and fish imperilment driven by beef production. Nature Sustainability, 3(4), 319–328, table 1, p. 321. [The percentages of national consumption are outlined in Table 1; it is our assessment that these crops are primarily used for animal feed.]
See also visuals of similar percentages from several of the same researchers in an earlier report: Marston, L., et al., (2018). High‐resolution water footprints of production of the United States. Water Resources Research, 54(3), 2288-2316, Figure 1A, p. 2301.
Richter, B. D., et al., (2020), p. 321.
Dieter, C.A. et al., (2018) Estimated Use of Water in the United States in 2015, U.S. Geological Survey, p. 59.
Water Use, Withdrawal and Consumption. https://www.watercalculator.org/footprint/water-use-withdrawal-consumption/