Alfalfa may be the solution to the looming water crisis in the West, a new study suggests

A new study from Utah State University suggests that the Colorado River basin states — including Arizona — may have a solution to the looming water crisis right under their noses: alfalfa.

The study proposes something called “deficit irrigation,” and Jonathan Thomspson said it just might work. Thompson is a contributing editor for High Country News, and the author of a newsletter called “The Land Desk,” where he recently wrote about the study.

He talked to The Show about how central this single crop is to life in the West.

Full conversation

JONATHAN THOMPSON: It's a type of clover, I believe, and it is a livestock forage crop that is grown pretty widely for hay. It has a high protein content and high nutrition content, making it good especially for dairy cattle as a feed.

DINGMAN: OK, and what is the connection, though, to the water supply?

THOMPSON: It is the biggest single crop as far as water users go on the Colorado River for two reasons. One is that it is kind of a thirsty crop. It uses a lot of water, but also simply because it's grown so much, there is so many acres of it. And it is a crop that is in warmer areas, like southern Arizona, central Arizona, basically, you can grow it year-round and harvest it year-round.

DINGMAN: And so, because of the massive amount of water that is necessary to maintain this very high level of production for alfalfa, you wrote up a piece on Substack about this idea being floated called deficit irrigation.

THOMPSON: Yeah. So what deficit irrigation is, is putting your crop on a water diet. It means completely cutting it off from water for a certain amount of time, or it can mean just irrigating it less. And that's one of the things about alfalfa that's kind of nice, is that you can actually cut off the water to an alfalfa crop for a certain amount of time, and it doesn't kill the crop.

It doesn't produce during that time necessarily, or it might produce less. But once you start watering it again, it usually comes back. And so you can kind of do this thing called deficit irrigation.

DINGMAN: And this is similar, right, to something that happens in energy that's known as demand response.

THOMPSON: Right. That's something that you talk about with, with the grid, the power grid. And that's where somebody like a big user — let's say a factory. When there is a potential of demand on the grid outpacing supply, you can go to that big user and say: "Shut off your machines or your computer processors" or whatever it is, and it's the same effect as generating more electricity.

And what they do on the grid is they'll actually pay these big users to stop using electricity at certain times. So this is the same concept with water. And the reason it could work with alfalfa is because, especially when you're talking about Arizona and Southern California, where not only are the crops big users, but you have, like, single farmers, single farms that are using enormous amounts of water for alfalfa. And so you can just go to one farmer or one or two farmers, and you can say, "Can we shut you off for three months because we're running into this serious dry spell and we need that water." ... And hopefully they'll say, yes, of course, they'll need to be paid for it.

DINGMAN: Well, and because the other proposal that sometimes gets floated around, this issue is paying farmers to fallow their fields. Why would this be different than that?

THOMPSON: Yeah. ... The fallowing thing is being used more often right now. That's kind of happening already. The problem with that is that in a lot of cases, for one thing, the irrigation systems have basically created their sort of own ecosystems, if you will, where wildlife come to depend on the alfalfa fields.

For example, deer will come and graze on them, or fish live in the ditches. And so when you fallow a field, you're basically turning a green field and a green space into a dust field. So deficit irrigation would be preferable to that.

DINGMAN: And the idea here, according to this, this study, which we should say was done at Utah State University, the estimates in that study are that this approach could save around 50% of the water currently being used for alfalfa. And the other idea is that farmers could potentially sell the water they're not using to other users or sell it back to the state?

THOMPSON: Yeah. One of the ideas here is to try to make it more of a free market kind of situation.

... As opposed to what's going on now where alfalfa farmers are being paid by the federal government or the state governments to just fallow their fields and to stop watering. This would be like these farmers could, by reducing the amount of water that they put on their fields, they would have surplus water that they could then sell to somebody else.

DINGMAN: Right. And would create like a mini water market.

THOMPSON: Yeah. And so a lot of it depends on whether it would work is, depends on the price of water and the amount of money somebody's willing to pay for this water, and whether that would offset the reduction in yield of the crop.

DINGMAN: So it seems like —I mean, obviously I'm not a farmer. But just based on the conversation we're having here and in reading your piece, it seems like the main issue here is the complexity of implementing something like this, Though it potentially offers more holistic benefits than the fallowing approach. There's a lot of moving parts.

THOMPSON: Right. I mean, when you look at the Colorado River system and you look at the Upper Basin, Lower Basin, basically alfalfa is the dominant crop everywhere. But there's a difference. I mean, if you start looking kind of more closely, you see that in the lower basin you've got these big farmers with these big fields and it's kind of more industrial and they're going to be easier to deal with because in the Upper Basin, you cruise around Colorado or something, you're going to see alfalfa all over the place.

But a lot of times it's on these little farms that are five, six, you know, 10 acres. And so in order to get the water savings that we need, you need like this large-scale implementation of this kind of thing.

... And I think it would be really difficult in places like Colorado because you go into these farms where it might be a garlic farm that also has a 5-acre alfalfa field that they supplement their income with, and you're not going to be able to get a whole lot of savings out of that.

DINGMAN: Right.

THOMPSON: Compared to the Lower Basin. And so again, a lot of the, the burden of this kind of cut and this kind of system is going to go on the Southern California, southern Arizona, central Arizona farmers, which is a really a big sticking point right now with Colorado river negotiations.

... Because the Lower Basin kind of feels like they're the ones who have to deal with these big cuts because at this point, the Lower Basin is — they're using all of the water that they are allocated in the Colorado River compact, which was signed in 1922 between all these states.

The Upper Basin, they are not using their total allocation yet. And the Upper Basin wants to be able to have the freedom to continue to develop more and grow more and use more. And the Lower Basin is saying, you know: "You just can't do that. You're going to have to stop growing and you're going to have to stop using more water. And in fact, you're going to have to cut your water use a little bit because we all have to share the pain equally."

DINGMAN: Well, it seems like a situation that is ripe for an innovative solution and this is a very interesting one to consider. Jonathan Thompson wrote about it on his Substack the Land Desk, and he's also a contributing editor for High Country News. Jonathan, thank you for this conversation.

THOMPSON: Thank you.