Trends in Alfalfa Growth and Groundwater Levels in Arizona

Author: Matthew T. Ford (University of Arizona)

  • Trends in Alfalfa Growth and Groundwater Levels in Arizona


    Trends in Alfalfa Growth and Groundwater Levels in Arizona



The federal government has been providing significant subsidies to the dairy industry since 1933. These subsidies are important to farmers and to the industry as a whole because they keep incomes steady during fluctuations in market prices. However, federal policies can also incentivize dairy production which increases agricultural production which has negative impacts on water resources. Here, we explore the impacts of dairy subsidies on groundwater storage in Arizona. On one hand, the dry climate, abundant sunshine, and good soil make Arizona an attractive location for alfalfa farms, and alfalfa is a major source of feed for the dairy cow population. However, Arizona has very limited surface water supplies, and irrigated agriculture often relies on groundwater. Groundwater use is unregulated in many rural parts of the state, which creates the potential for unsustainable pumping to support water-intensive crops like alfalfa. We present a retrospective analysis of alfalfa and dairy expansion across the state using datasets from CropScape, which uses satellites to determine ground cover, and the United States Department of Agriculture (USDA, 2021). Using data from the Arizona Department of Water Resources (ADWR), we explored how much alfalfa is being irrigated by renewable versus nonrenewable sources. Finally, we explored connections between alfalfa and groundwater levels.

Preliminary results show a correlation between increased alfalfa growth and declining water levels in areas where groundwater is alfalfa’s main irrigation source. Future work will explore spatial patterns in alfalfa expansion and groundwater declines relative to different regulatory frameworks across the state.

How to Cite:

Ford, M. T., (2022) “Trends in Alfalfa Growth and Groundwater Levels in Arizona”, Arizona Journal of Interdisciplinary Studies 8, 1-17.

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Published on
13 May 2022
Peer Reviewed