Hay growers seem evenly split on whether applying manure to alfalfa fields is a good idea or not, says Michael Russelle, soil scientist with USDA-Agricultural Research Service. About half the alfalfa growers he talks to say they would never do it, while the other half regularly apply manure to alfalfa. He'll give recommendations on the topic during a Feb. 5 presentation at the National Alfalfa Symposium in Kearney, NE.
Alfalfa can utilize manure nutrients quite efficiently, according to Russelle. "The benefits of using manure are many," he says. "When manure is applied appropriately before alfalfa planting or during production, it can improve yield and performance of the crop. However, if the manure application rate, method and timing are not done appropriately, there can be an increased risk of runoff to surface water or possibly a risk of spreading pathogens (between livestock herds)." Shallow injection reduces odor, runoff and crop damage, in addition to decreasing the risk of spreading livestock diseases. Partial incorporation can reduce nutrient losses due to runoff and volatilization, but some producers report stand damage with this method. Russelle urges growers to follow state manure application guidelines and regulations.
When applying manure to established alfalfa, he says growers should do it in a manner that minimizes the risk of runoff, and use lower rates near surface water according to phosphorus limitations. "Be quick, apply as soon as possible after the harvest and at least 30 days before the next harvest," he says. "Break up chunks of solid manure and spread evenly for good nutrient supply and to reduce stand damage." If serious disease is present or suspected in the livestock herd, the manure should not be applied to forages.
Russelle says preplant applications should be made on fields with the lowest fertility. Apply no more than a few weeks before planting on coarse-textured soils. Incorporate the manure deeply and thoroughly.
The National Alfalfa Symposium, sponsored by Hay & Forage Grower and the Nebraska Alfalfa Marketing Association, will take place Feb. 4-5 at the Ramada Inn and Conference Center in Kearney, NE, just prior to the Mid-America Alfalfa Expo.
For details on the symposium schedule or to register, visit alfalfasymposium.com. For information on the expo, visit alfalfaexpo.com/.