When faced with alfalfa winterkill or a hailed-out forage field in late spring, millets, especially pearl millet, could be an annual crop option worth considering. Several years of test plots in the Midwest have demonstrated that the crop can provide emergency forage or perform well as an economical one-year forage source.
After several years of serious winterkill to alfalfa, University of Wisconsin Extension specialists set up field trials to evaluate annual forage options, focusing on which worked better on sandy soils in the central part of the state. In a 2005-2007 study, they compared a wide range of annual crops, including 110-day corn, multi-tillering corn, oats, forage sorghum, sudangrass, a milo-soybean mix, soybeans, Italian ryegrass and three types of millet – Japanese, German and hybrid pearl.
“The millets did better than some of us expected,” says Keith VanderVelde, Marquette County ag Extension agent. “They produced fairly good forage quality, offered some planting flexibility and handled the heat of mid- to late summer.”
The biggest limitations of millets are their limited regrowth and their sensitivity to frost. Also, foxtail-type millets (Siberian, Hungarian and German) can’t be fed to horses because they contain a glucoside called setarian, which can damage kidneys, liver and bones.
In Wisconsin tests, pearl millet did especially well, having more height and mass than the other millets and better weed suppression than most other crops, says VanderVelde. It yielded 4.8 tons per acre of dry matter, and produced the third-highest amount of milk per ton at 3,293 lbs, behind oats and multi-tillering corn.
“Cattle and horses really loved it and would always eat it first when they had a choice, even preferring it to meadow fescue,” he says.
Craig Saxe, Juneau County ag Extension agent who also worked on the trials, says corn for silage is still probably his top recommendation for an emergency forage crop.
“But the trials convinced me of the value of millets, especially pearl millet,” says Saxe. “It would be a good fit when it’s too late to plant corn and handles high temperatures and dry conditions well. Those qualities would make it a good double crop as well as an emergency crop.”
“In two of the three years of our trials, we had limited moisture – 7½” during the summer of 2005 and just 4½” in 2006,” adds VanderVelde. “The millets all handled the heat better than most of the other crops.”
The millet crops’ height averaged about 35” when they were cut 65 days after planting, except for the pearl millet, which grew to nearly 6’ tall. Crude protein levels were 10.4% for pearl millet, 12.5% for German millet and 14.2% for Japanese millet. The latter produced 2.7 tons of dry matter per acre and 3,132 lbs of milk per ton of dry matter. German millet produced 5.4 tons of dry matter per acre and 15,366 lbs of milk per acre, which was third-highest behind sudangrass and corn.
Corn for silage and sudangrass also showed the highest forage quality, yet researchers concluded that pearl millet is worth considering for hay.
“All of the millets also were some of the lowest in seed cost per acre, at around $15,” adds VanderVelde. “That makes them a very efficient way to get a lot of forage with just one cut.”
Minimal regrowth is a downside, especially to German and Siberian millets, says Steve Zwinger. A research agronomist at the North Dakota State University (NDSU) Carrington Research Extension Center, Zwinger has run crop variety tests for more than 15 years.
“After cutting pearl millet, for instance, there is usually not enough regrowth in central North Dakota to justify another cutting. You can expect a little more regrowth with Japanese millet and could possibly get another cutting in early fall farther south – in southern Minnesota and Iowa. Most growers around here just graze the field after taking the cutting.”
Japanese millet resembles barnyardgrass and is the fastest-growing millet. In Southern states it can reach the ripe-grain stage in just 45 days with enough heat and moisture. But in the North it usually takes 60-65 days to mature.
“It has thicker stems, which can make drydown more challenging for hay,” says Zwinger. Millets like warm soils, so he recommends planting them in June or as late as early July.
“We recommend seeding the foxtail-type and pearl millets at about 20 lbs/acre and Japanese millet at around 30 lbs/acre. When they are going to be used for forage, it pays to err on the high side so you get a thicker stand.”