But more growers are plowing up alfalfa stands, replacing them with corn, soybeans or some other higher-value – or higher-yielding – crops.
A total of 2.38 million acres of alfalfa and alfalfa mixes were seeded in the U.S. in 2012. That was a 3% increase over the acreage sown in 2011, but the first increase in seeded acreage since 2005, according to the National Agricultural Statistics Service (NASS). It was also the second smallest amount ever seeded. Harvested acres of alfalfa and alfalfa mixtures increased slightly in 2013, to 17.6 million acres, from 17.3 million in 2012.
Historically, alfalfa acres have declined steadily. Since the late 1950s and early 1960s, when acres harvested were at their highs of 26 million to 29 million acres, they’ve gradually shrunk to 21 million acres in 2009 to 19.9 million in 2010 and 19.2 million in 2011.
Corn silage acres in Western states, in comparison, have increased eightfold since 1919 and have doubled since 1992. So says University of Arizona Extension agronomist Mike Ottman, quoting NASS numbers.
That corn silage increase corresponds with an increase in milk production and a decrease in hay and haylage use, added Ottman during a Western Alfalfa & Forage Symposium presentation in mid-December. “There is little doubt that alfalfa hay production in the Western states has not kept pace with the rapid expansion of dairy production in Western states – the difference being made up mostly by corn and small grain silage, and by grain and other concentrate feeds.”
The so-called “Queen of Forages” could be losing its crown. The reason, says Dean Doornink, is its lack of improvement in yield.
Doornink is a “money-conscious farmer” feeding 1,700 milk cows and 1,300 youngstock on 1,600 acres outside of Baldwin, WI.
“On that limited land base, we have to grow as much as we possibly can. Corn silage in our area is getting yields of about 20 tons/acre at 65% moisture and that works out to be 7 tons of dry matter per acre. Our harvest costs run around $6.50/ton,” he points out, because the crop is custom-harvested.
“Then I look at alfalfa for haylage. If we have a real good year, we have 4.5 tons/acre. We harvest four times and our harvest costs are running $50/ton of dry matter.”
His cows’ diets had been running 60% corn silage and 40% haylage as the forage portion of his 50:50 grains vs. forage diets. But, in late November, he started feeding Shredlage, silage corn shredded at a long particle length to provide more effective fiber in the ration. “Our nutritionist plans to go 80% corn silage and 20% haylage. I have heard some of the very early adopters are going to 100% corn silage.
“There needs to be more known about Shredlage,” Doornink admits. “But if it becomes adopted by a lot of dairymen, I suspect that the alfalfa needed in the dairy ration will be decreased.
“If you have enough land and alfalfa is $300/ton and corn silage $50/ton … maybe the economics will dictate that more alfalfa acres will be grown. But for our situation, with limited land base, we need to grow as many tons of dry matter as we possibly can. We are not getting it out of alfalfa.”
Doornink contends that breeding efforts in alfalfa haven’t kept up with those in corn. Ron Hatfield, a USDA plant physiologist with the U.S. Dairy Forage Research Center, agrees.
“Corn yields have been going up steadily for the last 20 years. Sometimes, genetics improved the production levels. But it’s interesting, too, that as we changed the management of corn, we’ve also selected for corn that can tolerate higher-density populations.”
According to NASS data, the national average corn grain yield has increased from 26 bu/acre in 1939 to 165 bu/acre today.
Alfalfa yields, from 1920 to 1959, averaged 2.1 tons/acre vs. a 3-ton/acre average from 1960 to 1990. In the last 12 years, alfalfa yields averaged 3.4 tons/acre, according to NASS, although growers and forage specialists will say those numbers are low. University of California data indicate a Western alfalfa yield average close to 5 tons/acre. One breeding company representative says 9-10 tons/acre from seven to nine cuttings is today’s “norm” for irrigated alfalfa in Western states.
A USDA-Agricultural Research Service (ARS) report contends there is a two- to threefold yield gap between what “average” producers report to NASS and the Census of Agriculture and what is achievable. Growers likely don’t know how much crop they produce, says Michael Russelle, a research soil scientist with ARS and author of The Alfalfa Yield Gap: A Review of the Evidence.
It’s only fair to point out that corn, as a diploid composed of two sets of chromosomes, is less complicated to breed than alfalfa, a tetraploid containing four chromosomes, says Hatfield.
“But there is no doubt that we can improve the genetic potential of alfalfa; there is good evidence that suggests we could select for higher yields. At the same time, higher yields have also depended upon how well you manage that alfalfa.”
Early alfalfa breeding efforts concentrated on forage quality, Hatfield says. ”To get that highest quality, you just cut the alfalfa more frequently. So a lot of effort’s been put into selecting for alfalfa that could tolerate frequent cuttings.
“I think those two things (yield and quality) could have gone hand in hand, but for some reason, people were so fixated on the quality side that that became the overriding selection criterion.”
That doesn’t mean alfalfa yields haven’t improved, say Hatfield and breeding company representatives.
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