Alfalfa is a weed in my climate. It volunteers in unirrigated spaces in my semi-arid backyard. (18 inches of rain a year.) It gets big and full of edible leaves with no effort whatsoever. I use it as chop-and-drop all the time. It grows back, no matter how hard I try to chop it down. I never water it. It’s a pure weed. It’s a perfect fit for an edible chop-and-drop bush in the American southwest.
My mom grew up in another part of the American southwest that was a little hotter and significantly dryer. (7 inches of rain a year.) Alfalfa was a weed for her family, too.
And yet I keep hearing that when farmers grow alfalfa for animal feed in the American southwest, they have to use ridiculous quantities of water, because alfalfa has to be kept moist all the time.
I . . . I truly don’t understand. What is going on here? I know alfalfa can grow happily without any irrigation at all in an arid climate (and in sandy soil with almost no organic matter that drains rainwater away really fast, to boot). How is it possible that it’s also a crop that needs gigantic quantities of water in exact same climate?
I’m hoping somebody knows, because I’m truly stumped.
I suspect it’s similar to what was done with modern wheat. Borlaug prioritized yield. The new varieties were aggressively (and I would argue recklessly) adopted based on yield improvements.
Wheat has been traditionally dry-farmed in areas with similar precipitation to yours for millenia. You can’t realistically attempt this with the shallow-rooted, fertilizer-dependent, genetically bottlenecked modern derivatives of Norin 10. This is without even getting into the many health concerns posed by consumption of green revolution wheat.
Like Joseph says, you get what you select for, whether you mean to or not.
Or, like you say, if you optimize for something you are not optimizing for something else.
My understanding is alfalfa was optimized for fast growth and regrowth (including the ability to take many cuttings per season), high yield, and a particular nutrient profile, with water usage as a minimal concern.
People can wreck any crop for a given context through stewardship. I feel confident my seeds in a few years (if not already) would do terrible in the desolate moonscape of agribusiness, which has been selecting first for profitability for decades (whatever nice things might be said about feeding the world) while ignoring the hidden costs.
It would be great to see innovation and collaboration in the same vein and beyond what was shown in the green revolution applied to a fresh start with wheat, alfalfa, and other crops. One could argue like what is happening with GTS right now
I’d say they probably want results immediately. Bank won’t wait.
I’ve heard they grow an enormous penroot, I can imagine that takes a couple of years to develop. But as they need results a day after seeding they moddycoddle them to death. And it grows big with no pen root to speak off.
So then if water is down, they die off. And farmers start to believe it’s done like this by the guys making the big money. Never mind listening to old people or green weird hippie farmers. A generation later probably gets it taught in schools it has to be done like that.
My two cents:
If you start growing something with plenty of irrigation, it doesn’t develop deep roots and is dependent of frequent irrigation. If you grow it with scarce water, the plant is forced to develop deep roots, and as a result it grows more slowly but can survive longer periodos without water.
I think they didn’t let their crops grow deep roots, and it suffers without irrigation.
Hmm. That reminds me of something Carol Deppe said in one of her books: If you select for squashes that grow the biggest leaves the most quickly, you will probably select against the squashes that grow the deepest roots the most quickly, and thus you are selecting against drought tolerance.
If that’s true for most plants (which seems likely), that may explain what has happened to commercial alfalfa varieties.
In which case . . . (headdesk).
I keep noticing situations where it’s quite easy to unintentionally act against your own best interest if you only look at short-term results and ignore long-term consequences. (For instance, it’s not great for your health if you eat only candy and never exercise.) I guess this must be one of them.
In my short-season ecosystem, Alfalfa can grow dry farmed, or irrigated. Dry farmed fields yield one great crop, and sometimes a second sparse crop. Irrigated fields can yield three great crops.
Ahhhh. So it may not even be about genetic shifts – it may be about teaching those particular perennial individuals that they don’t have to bother implementing sensible survival strategies they would otherwise do.
It’s all about cuttings and tonnage. Alfalfa can be cut on a set schedule if you have enough growth. Like 28, 32, or 45 days.
It’s about return on investment. If I want a building but it’s only for 6wks to house the sheep to lamb. Well I better have alot of ewes for the large investment for a building. And a building only being used to 6wks doesn’t make sense so instead you get more sheep and lamb several groups four times through the year. Then I don’t have a building only being used 6 out of 52 weeks of the year.
If you’re leasing the field, and alot are leased, then you’re paying X $ per acre whether you make 1 hay bale or 1,000 hay bales. Makes more sense to get more for the same lease investment cost.
I could argue that alot of the added costs of irrigation etc are causing more problems and costs than makes sense for one more hay cutting. But ultimately it’s up to that farmer or farm manager making those decisions. For the most part we aren’t changing their mind because “this is the way it’s done”.