Which states come to mind when you think about irrigation? It might surprise some to know that Arkansas ranks fourth in the country in irrigated acreage, following Nebraska, California and Texas. However, the irrigated acreage in the top three states is not increasing and in some cases it has decreased in recent years while Arkansas' irrigated acreage continues to increase.

People in these states question why we have so many irrigated acres when our average rainfall is about 50 inches. They don't realize that approximately one-third of the irrigated acreage is flooded rice, and they don't know how little of that 50 inches actually comes during the production season.

The fact that many of our soils have a limited or restricted rooting depth is another condition that they probably don't face to the degree that we do here in Arkansas.

The irrigated acreage in Arkansas will vary from year to year, but it is estimated to be about 4.6 million acres of the approximately 6.2 million acres of row crops that are produced in the summer. Do the math — almost 75 percent of the 6.2 million acres are irrigated.

The accompanying table gives the breakdown for each of the crops. The crop acres and irrigated percentages may vary some, but there is no doubt that we irrigate over 4 million acres in Arkansas.

Arkansas irrigation estimates
Crop Total acres Irrigated acres (percent)
Rice 1,600,000 1,600,000 (100)
Soybeans 3,000,000 1,860,000 (62)
Cotton 1,000,000 750,000 (75)
Corn 350,000 280,000 (80)
Sorghum 250,000 125,000 (50)
TOTAL 6,200,000 4,615,000 (74)

It appears that row crop irrigation has the potential to move from some of the traditional irrigated areas and into the Delta and Southeastern states. It comes as no surprise that this is a result of diminishing irrigation water supplies in areas like Texas.

Of course, past articles in this publication as well as others make the point that there is not an unlimited irrigation water resource in the Delta or Southeast. However, there are areas where the irrigation water resource will support an increase in irrigated acres.

Another force behind increased irrigation acreage is how it affects a grower getting a crop production loan. Many of the sources for crop loans are at best reluctant to make loans to producers who have a limited ability to irrigate their crops.

The risk associated with dryland farming in today's environment is very high. In fact, many landlords are finding that it is getting difficult to get someone to rent fields that can't be irrigated or that have only a limited irrigation capacity.

It is also possible that the irrigated percentage in Arkansas and other areas could increase due to some of the conservation program provisions of the farm bill and other programs that support development of surface water for irrigation. When more marginal production acres can be put into conservation programs or used for developing surface water storage, the irrigated acres may not necessarily increase but the irrigated percentage for the farm would increase.

I believe that this points to the need for continued research and field demonstrations of improved methods for irrigation water management so we can best assure the most effective development and use of our precious water resource.

This is backed up by the fact that in 2002 the USDA-ARS proposed a National Irrigation Watershed Research Lab to be placed in Arkansas. Of course, this would require special appropriations, and many would argue whether this is the best use of funds. Regardless, it confirms to me that we have a unique and challenging opportunity here in the Natural State that I look forward to being a part of.


This is one of several articles on drainage and irrigation water management. If you have questions or suggestions on topics please contact me: Phil Tacker, 501-671-2267 (office), 501-671-2303 (fax), 501-944-0708 (cell), or ptacker@uaex.edu (e-mail).

Phil Tacker is an Arkansas Extension ag engineer.