Alabamians have been talking about irrigation as an economic development activity for the past several years, says McNider.

“It started out as an academic exercise,” he says. “We were looking at common problems that universities in the state could work on together. But it turned out that what started as an academic exercise also was of great economic importance to the state. Out of that grew the Alabama University Irrigation Initiative, with the purpose of bringing back the state’s agriculture by expanding irrigation.”

Researchers first looked at the question of whether or not irrigation was viable, says McNider.

“We ran some crop models in the Black Belt region of the state, which used to be one of the largest agricultural areas in the state. When the soils in that region become dry, they crack, and when they crack, water can’t be delivered to the plants. Those lands went out of production because they were very vulnerable to drought. But the Black Belt, in our crop models, responded the best to irrigation.”

The amount of water available in the state also has been a focus, says McNider. “While we have abundant water, we have to be careful that our eco-systems, including our rivers and streams, have evolved based on this abundance of water. We can’t be cavalier and assume that just because we have water, it’s not possible to cause stress to our eco-systems. So we need to understand how much water we can draw for irrigation and not harm our environment. We also need to develop tools to determine the impacts on the streams and rivers.”

There are two factors to consider when looking at how much water is available, he says. “What’s the demand in terms of the use of the water, and how much water is supplied, which is how much you get from rainfall. The ratio of those is an indicator of how much water you have.”

Looking at water use throughout the United States, in the eastern portion of the country, for the most part, less than 10 percent of the supplied water is used, says McNider.

“But when we have extreme droughts, our stream flows go down, and the water supply actually decreases, so it doesn’t look as good as the overall average.”

Streams in Alabama have a huge annual cycle, he explains. “In the wintertime, there is plentiful water in the streams and rivers, but in the summer, the flows go down to very low levels. Unfortunately, farmers need water the most during the summer. So we’ve looked at systems that allow us to pull from those winter waters. The winter water we have in our streams is comparable to the snow-packs in the West, and we need to use that in the form of on-farm reservoirs to serve irrigation needs. If we pull from the streams when there’s plenty of water, then we won’t stress the supply so much in the summer.”

Researchers also have looked at how many irrigated acres can be supported in Alabama.

“We do have water protection in the state legislation that grants incentives for installing new irrigation systems. But we don’t have the language that is needed in that we don’t need to provide incentives within the watersheds that are already stressed. We need the tools that will tell us when watersheds are already oversubscribed – that’s a problem that they’ve had in the Western U.S.”

The Alabama Geological Survey also has begun to do an analysis of groundwater as a source of irrigation water, says McNider.

“In addition, we’re looking at where the land is located in the state that we can irrigate and how close it is located to a water supply.”

In a drought year, not having irrigation or even irrigating 50 percent of the state’s land costs Alabama close to half a billion dollars, he says.

“This is what led to the state tax credit for farmers who are willing to invest in irrigation. The state comes close to getting its return back from that tax credit in a couple of years because of increased yields. In the past, farmers were losing money and writing off their losses.”

phollis@farmpress.com

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