LINNEUS, Mo. -- Growing alfalfa has the same requirement as murder in the first degree, a University of Missouri (MU) forage specialist said. It takes premeditation.
Rob Kallenbach, MU extension specialist, was one of a half dozen speakers in a day-long workshop who helped describe planning needed to grow the high-quality forage crop.
Improving the fertility for alfalfa must start at least six months, preferably a year, in advance by adding lime to the field, Kallenbach said. Phosphorous and potassium fertility must also be added in advance.
However, the crop does not require nitrogen fertilizer. As a legume, it adds nitrogen fertility to the soil.
Almost every farm with livestock can find a place for alfalfa, said Kevin Moore, MU extension economist. He described the expenses and returns from alfalfa with sample budgets for growing alfalfa for hay, silage, and grazing.
Alfalfa in grazing systems, instead of just for hay, received attention during a workshop at the MU Forage Systems Research Center (FSRC).
Farmers attending the workshop raised questions about bloat, a sometimes fatal condition in animals that graze too much of the legume under the wrong conditions. Bloat was described as formation of bubbles in the animal rumen where forage is digested. The foam prevents animals from belching. The gas pressure squeezes internal organs, leading to death.
Jim Gerrish, research agronomist, said that after thousands of "animal grazing years" only two cows had died from bloat at the research farm. For grazing, the legume is best used when grown with grass. That reduces the risk and improves the diet.
Kallenbach said farmers lose more money from fear of bloat than from actual bloat. Fear of bloat prevents them from using the crop.
Gerrish said that while bloat is a real concern, it can be overcome with grazing management.
"Livestock should not be moved onto alfalfa damp with rain or dew if they are likely to be hungry," Gerrish said. Moving cattle later in the day, after morning dew has dried, is a good preventive measure. Animals should be limited in alfalfa intake as they are introduced to the forage.
One way to control intake is to feed cows dry hay, before they are put on an alfalfa pasture for the first time.
Also, feeding "bloat guard" in a mineral block can reduce the condition Wayne Bailey, MU extension entomologist, led the group into a field to collect alfalfa weevil -- and the natural predators that help control the pest. Bailey pointed out that grazing could reduce the number of weevils. When cows eat the top two-thirds of the alfalfa plant, they remove about 95% of the weevils. Grazing can be started about a week ahead of the usual hay cutting time.
Producers in north Missouri usually have fewer problems with weevil than producers in the south, Bailey said.
David Davis, agronomist, said new varieties of alfalfa will have increased resistance to potato leafhopper, another insect pest.
Davis urged producers not to skimp on seed costs when purchasing seed. While new improved seed costs more, the return can be greater.
Jerry Nelson, MU alfalfa researcher, brought flats of alfalfa seedlings planted in different soils. He demonstrated that the best seedling emergence was in rows planted only one-quarter of an inch deep. Seed planted 1.5 inch deep had few seedlings and the seedlings were much weaker. Shallow seed placement is essential for a good stand. Also, growth is better in sandy loam with good drainage.
All of the specialists listed benefits of using the forage, which is high in protein.
They also cautioned that it requires more expense to establish and requires a higher degree of management. Traditionally, dairy producers have used alfalfa to reduce the expense of protein in the feed ration. But the forage also has a place in beef operations, said the speakers.
While establishment costs are higher, Moore said, that could be offset by keeping the stand productive for more years. Production and persistence go together, he said.
The alfalfa workshop was part of series of quarterly workshops to be held at FSRC and the MU Thompson Farm, said David Davis, new superintendent at the two farms. The plan is to increase the outreach to producers across the state from the farms, part of the MU Agricultural Experiment Station.