DIVISION OF AGRICULTURE RESEARCH & EXTENSION University of System Agriculture and Natural Resources

FSA51

Arkansas Irrigation

Irrigation is a critical component of fact sheet is to indicate the trends and Grant West the agricultural economy of Arkansas. magnitude of irrigated agriculture in Program Associate Among the top five agric ultural com- the state and to provide comparisons modities by farm receipts in 2012 were with other states that heavily depend Kent Kovacs soybean, rice and c otton. All of these on irrigation. Associate Professor crops depend on irrigation to increase yields. The information in the figures and tables below comes from the 2007 Alluvial Aquifer The Mississippi Alluvial Aquifer Christopher Henry and 2012 Censuses of Agriculture and Associate Professor the USDA 2013 Farm and Ranch (or “alluvial aquifer”) lies beneath the I rrigation S urvey. The purpose of this states of Arkansas, , Isaac Engram Graduate Research Figure 1. The Mississippi Alluvial Aquifer Assistant Illinois Depth to Water (ft.) □ 1. 70-25 Qiuqiong Huang - 25 .01 - 50 ■ Professor entucky - 50.01-75 - 75 .01-100

- 100.01 - 125 - 125.01 - 1EO ---- State Boundaries LJ County Bound aries c::JM ississippi Allu vial Aqu~er ext ents

Arkans:iS \ 0 20 40 so 120 160 -=:-==---===-- Miles

Figure 1. Depth to groundw ate r of th e Mississippi Alluvial Aquifer.

Notes: Aquifer extent s acquired from USGS thro ugh Nationa lAtlas.gov. Ground wate r surface was int erpolated from well \ meas urements using Neare st Neigi'lbor technique. The well depth measure ments come from th e U&GS Active Groundwate r Arkansas Is l evel Netwo rk and U&GSN ationa l Louisiana Waler Informat ion Service. Data Our Campus include 219 wells in AR, 256 wells in MS, 16 wells in I.A,7 wells in MD, and 4 wells in ll. MS,M O, and LA data from 2013. AR and ILda ta 'rom 2014 . Visit our web site at: https://www.uaex.uada.edu

University of Arkansas, United States Department of Agriculture, and County Governments Cooperating

Mississippi, , Illinois, and Figure 2. Critical groundwater areas. Tennessee. The aquifer extends over roughly 19,000 square miles in Arkansas. The depth to water in the aquifer varies from 1.7 to 150 feet at the deepest section. The shallowest depths run along the Mississippi River, while the aquifer surface gets deeper further away from the river. The deepest area is near the center of Arkansas.

Arkansas Critical Groundwater Areas Critical groundwater areas defined by the Arkansas Natural Resources Commission are areas determined to have “significant groundwater depletion or degradation.” The critical groundwater areas are concentrated in the Delta and in South . Ground- water depletion in the Delta is most significant in the SO\llh Atbnsaa fo, SPIN In t'" Gr•nd Prairie for Sp,tN & Alluvl•I In ttN Grand Prairie and at the western edge of Crowley’s Cache for Sp,1'1¥Memphla 9-nd & Alluvl .. In 2oot Phillipa County for Alluvlal In 2015 Ridge. This is where water-intensive rice production is the most prominent (Figure 2). Legend - o-..­ Farmers in critical groundwater areas receive '9 eu--rentCritic.a1AIN1 0 10 20 ,o eo eo higher priority to qualify for state and federal -- cost-sharing programs and credits for conservation practices. Between 2007 and 2012 agricultural census years, Arkansas’ irrigated base expanded by Arkansas Is One of the Leading 343,220 acres. States in Irrigated Acres Out of the 55.8 million acres nationally under As of 2012, Arkansas has the third largest irrigation in 2012, about 8.6 percent are located irrigated acres, totaling 4.8 million acres in Arkansas. (Figure 3).

Figure 3. Top ten states in total irrigated acres (million acres). I I I I I I I I I 8.3

California .86

Arkansas 1.8

Texas 4.49

Idaho 3.37

Kansas 2.88

Colorado 2.5

Montana 1.9

Mississippi 1.15

Washington u l3 I I 0 1 2 3 4 5 6 7 8 9

Source: NASS-USDA, 2012 Census of Agriculture • About three out of five c ropland acres in Table 1. Irrigation Expansion, 2007-20 12. Arkansas are under irrigation. Change in Irrigated Acres 2007-2012 National Irrigation Expansion Ranking State Acreage Percentage Arkansas' irrigated acres expanded more than all other states, with the exception of M ississippi 1 Nebraska -261,986 -3.1% (Table 1). 2 California -154,495 -1.9% 3 Arkansas 343,220 7.7% In general, the Western states saw a decline in 4 Texas -521,253 -10.4% irrigated acres over the five-year period due to water 5 Idaho 65,403 2.0% supply scarcity caused by drought. 6 118,544 4.3% Irrigation expanded in the Southern states 7 Colorado -351,172 -12.2% where water is more readily available and prolonged 8 -110,148 -5.5% drought conditions are less frequent. 9 Mississippi 283,317 20.7% 10 Washington -102,346 -5.7%

State’s Irrigation Concentration Source: NASS-USDA, 2012 Census of Agriculture The percentage of irrigated acres in Arkansas counties roughly corresponds to each county’s Table 2. Top 25 Arkansas counties in 2012 total irrigated proximity to the Mississippi Alluvial Aquifer acres. (Figure 4). 2007-2012 Change Irrigated Acres in Irrigated Acres Arkansas’ irrigated acres lie mostly in the Delta County 2012 2007 Acres % region and along the Mississippi and Arkansas rivers. This is because those farms typically have Arkansas ---- 314,596 310,745 3,851 1% more productive soils and water availability. Poinsett 310,028 262,180 47,848 18% Mississippi 286,923 269,564 17,359 6% Figure 4. Total irrigated acres by county for 2012. Craighead 271,621 244,365 27,256 11% Clay 235,621 227,000 8,621 4% Phillips 231,860 245,359 -13,499 -6% Cross 214,710 191,622 23,088 12% St. Francis 209,256 144,804 64,452 45% Jefferson 207,481 200,247 7,234 4% Jackson 206,529 178,101 28,428 16% Desha 202,069 229,730 -27,661 -12% Lonoke 199,627 211,362 -11,735 -6% % of total county acres Monroe 199,486 163,211 36,275 22% LJ (D) - 0 - 1% Chicot 197,142 141,805 55,337 39% . 1.1 -25 %

- 25.1 - 50% Woodruff 196,986 169,456 27,530 16% - 50.1-63 % Prairie 179,147 176,263 2,884 2% (D) = Cannot disclose data for individual farms. Crittenden 173,321 138,102 35,219 26% Source: NASS-USDA, 2012 Census of Agriculture Greene 165,966 164,615 1,351 1% There is also a substantial number of irrigated Lee 157,999 174,518 -16,519 -9% acres in the River Valley and along the Red River. Lincoln 135,047 99,861 35,186 35% Lawrence 130,317 130,983 -666 -1% County Irrigation Changes, Ashley 70,755 90,804 -20,049 -22% 2007-2012 Drew 66,873 59,337 7,536 13% Between 2007 and 2012, 17 of the top 25 counties in Arkansas experienced an expansion of irrigated Randolph 56,920 67,301 -10,381 -15% acreage (Table 2). White 39,358 43,243 -3,885 -9%

While the overall net change in irrigated acres Source: NASS-USDA, 2012 Census of Agriculture was positive, there was much variation in growth rate between different counties. The average irrigation water applied per acre in Figure 5. Change in irrigated acres by county, Arkansas in 2013 was 16 inches. 2007-2012. This is the same rate of application as Texas but less than the 37 inches in California and more than the 12 inches in Nebraska.

Percentage of Irrigation Water by Source Type Nebraska, Arkansas and Texas obtain over 80 percent of their irrigation water from groundwater sources. At 13.9 percent, Arkansas has the highest percentage of on-farm surface water used for irriga- tion of the five states that irrigate most (Figure 7). California and Idaho use off-farm water for over 45 percent of their irrigation needs, while Nebraska, Arkansas and Texas use less than 10 percent from off-farm sources.

Source: NASS-USDA, 2012 Census of Agriculture St. Francis, Chicot and Poinsett counties were the Prominence of Gravity Application leading contributors to the increase in irrigated acres. Gravity application systems make up 86 percent Collectively these three counties account for 167,637 of the irrigated systems used in Arkansas (Figure 8). acres of increased irrigation acreage, a 34 percent This is due to the large number of rice acres in increase over the five-year period. Six counties, all in Arkansas under flood irrigation and the fact that the Delta, had decreases of over 10,000 acres. furrow irrigation is typically less expensive than sprinkler irrigation. Water Application Rates by State Arkansas ranks third among states in total volume of water applied for irrigation (Figure 6). Flow Meter Use by State States that use the alluvial aquifer have The total water applied in 2013 to Arkansas 6 percent or less of irrigated acres that use flow irrigated acres was 6.45 million acre-feet. meters (Figure 9). The percentage is likely higher in Mississippi now since their 2011 metering program.

Figure 6. Top ten states in quantity of water applied. Total Acre-Feet of Water Applied (million acre-feet)

California 3.49

Nebraska 8.07

Arkansas 6.4S

Idaho 6.42

Texas 5.80

Colorado 4.14

Arizona 3.76

Washington 3.66

Kansas .43

Oregon 2. 17

0 2 4 6 8 10 12 14 16 18 20 22 24 26

Source: NASS-USDA, 2013 Farm and Ranch Irrigation Survey

Figure 7. Percentage quantity of water applied by source: 2013. 100%------92 85 87 80% ------

60% ------50 48 42 39 40%

20% 9

0% California Nebraska Arkansas Idaho Texas

■ Groundwater ■ On-Farm Surface Water ■ Off-Farm Water

Source: NASS-USDA, 2013 Farm and Ranch Irrigation Survey

Figure 8. Arkansas irrigated acreage by type of system: 2013. 86 .8

80%------

60%------

40%------

20%------

0 .58 0% ■ Pressurized ■ Furrow/Flood ■ Drip and Low-Flow

Source: NASS-USDA, 2013 Farm and Ranch Irrigation Survey

Figure 9. Percentage irrigated acres using flow meters: 2013. Nebraska

California

Arkansas Texas - Idaho

Kansas

Montana I

Colorado

Mississippi Washington - 0% 20% 40% 60% 80% 100%

Source: NASS-USDA, 2013 Farm and Ranch Irrigation Survey The four states that rank highest in the use of flow meters draw water primarily from the High References Plains Aquifer. For additional information see: • Arkansas Natural Resources Commission at Summary https://static.ark.org/eeuploads/anrc/Critical_area • Irrigation in Arkansas is expanding, especially in _Fact_Sheet_2015.pdf the northeastern part of the state and along the • Lower Mississippi Gulf Water Science Center, Mississippi River. USGS at https://www.usgs.gov/centers/lmg-water/ • The vast majority of Arkansas irrigation is • U.S. Census of Agriculture at gravity flow sourced from the Mississippi Alluvial https://www.agcensus.usda.gov/Publications/2012/ Aquifer. and https://www.agcensus.usda.gov/Publications • Arkansas producers have more irrigated /2012/Online_Resources/Farm_and_Ranch acres and apply more irrigation water than _Irrigation_Survey/ 47 other states.

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GRANT WEST is a program associate, KENT KOVACS is an Issued in furtherance of Cooperative Extension work, Acts of May 8 and associate professor, ISAAC ENGRAM is a graduate research assistant, June 30, 1914, in cooperation with the U.S. Department of Agriculture, and QUIQIONG HUANG is a professor with the Department of Director, Cooperative Extension Service, University of Arkansas. The Agricultural Economics and Agribusiness, University of Arkansas in University of Arkansas System Division of Agriculture offers all its Fayetteville. CHRISTOPHER HENRY is an associate professor and Extension and Research programs and services without regard to race, water management engineer with the Department of Biological and color, sex, gender identity, sexual orientation, national origin, religion, Agricultural Engineering, University of Arkansas, Fayetteville. age, disability, marital or veteran status, genetic information, or any other legally protected status, and is an Affirmative Action/Equal FSA51-PD-2-20N Opportunity Employer.