Surface irrigation in the Lower Mississippi River Basin: Trends and Innovations

Authors: Reba, Michele; Massey, Joseph

Submitted to: Transactions of the ASABE
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 5/16/2020
Publication Date: 5/1/2020
Citation: Reba, M.L., Massey, J. 2020. Surface irrigation in the Lower Mississippi River Basin: Trends and Innovations. Transactions of the ASABE. 63(5): 1305-1314. https://doi.org/10.13031/trans.13970.
DOI: https://doi.org/10.13031/trans.13970

Interpretive Summary: The Lower Mississippi River Basin (LMRB) is an agricultural region of national and international significance. The region relies heavily on the Mississippi River Valley Alluvial Aquifer to provide over 80% of the irrigation water to 4 million hectares of cropland. The regions geology and increases in irrigated land have led to significant aquifer declines in portions of Mississippi and Arkansas. Attempts to address these declines have been multi-faceted and include specific innovation in practices and programs from state and local entities. These practices and programs are described in detail. Land managers, state and federal entities interested in LMRB long-term sustainability and crop production will be interested in this review paper.

Technical Abstract: The Lower Mississippi River Basin (LMRB) is an agricultural region of national and international significance. The basin relies heavily on the Mississippi River Valley Alluvial Aquifer to provide over 80% of the irrigation applied to over four million hectares of cropland. Surface methods, especially furrow irrigation using lay-flat, plastic tubing in corn, cotton, peanut, and soybean and flood methods in rice, predominate. Irrigation extent has steadily increased by approximately 2% yr-1 such that irrigation withdrawals, combined with the region’s geology, have led to significant aquifer declines in portions of Mississippi and Arkansas. Attempts to address these declines have been multi-faceted. Irrigation conservation innovations include: land-leveling, computerized hole-selection, reduced- or no-flood rice irrigation, and pump automation. The adoption of these practices remains heavily reliant on human-to-human interactions (i.e., extension activities). Leveling began in earnest in the 1980’s and continues to the present day. As cropland is leveled, overhead sprinkler use is curtailed in favor of furrow or flood techniques. Computerized hole selection (CHS), developed in the 1990’s, optimizes hole placement and size in lay-flat poly-tubing. CHS adoption has steadily increased, especially after release in 2014 of a web-based version of the software. Today, over 650 K ha cropland use CHS. Efforts to increase surface water use range from on-farm reservoirs to regional-scale river diversions. Owing to the concerted efforts of producers and others, good progress has been made in making surface irrigation more efficient and less reliant on groundwater. Yet, aquifer decline remains as a significant challenge to the LMRB’s economy, ecology, and culture.