Poultry litter offers benefits, risks

By Mike Rankin

Poultry litter is a commonly used nutrient source for pastures in many parts of the United States. Where the poultry industry has a strong foothold, litter is widely available and, in many cases, poultry production is a complementary enterprise on the beef or dairy farm where the litter is utilized.

Poultry litter is a mixture of manure, bedding, feathers, and spilled feed, according to Vanessa Corriher-Olson, forage specialist with Texas AgriLife Extension.

“The actual nutrient content of a manure sample varies,” Corriher-Olson explains. “The nutrient concentration of poultry litter is variable due to age of bird, composition of the diet, how the manure is handled, and the number of batches of birds raised since the last house clean out.”

Animal manure is a complete fertilizer, containing all nutrients necessary for plant growth. The forage specialist also notes it is high in organic matter. As the organic matter decays, nutrients are released into the soil over time. This reduces leaching of soluble nutrients like N, sulfur, and boron from the soil during periods of heavy rainfall.

Poultry litter averages about 62 pounds per ton of nitrogen (N), 59 pounds per ton of phosphorus (P), and 40 pounds per ton of potassium (K).

Corriher-Olson notes that when poultry litter is applied to a pasture, 60% to 65% of the N is available in the first year. About 25% to 30% is lost through ammonia volatilization, and about 10% is not available until after the first year.

“For optimum utilization, use poultry fertilizer to meet as much of the crops’ phosphorus and nitrogen needs as possible, then use commercial fertilizer to supply other nutrients to the levels indicated by a soil test,” Corriher-Olson advises. “Having your manure analyzed for its actual plant nutrient content is recommended. Armed with this and the appropriate soil test information, you can decide on the best plan of action to use poultry litter for specific cropping needs.”

Phosphorus build up in the soil can easily occur if poultry litter is the only fertilizer used, which can lead to environmental consequences if it moves off the field and into surface waters. To prevent this from occurring, application rates of litter may need to be reduced and then supplemented with commercial N fertilizer or the use of legumes.

“Keep in mind that many suppliers will only deliver large truck loads of poultry litter,” Corriher-Olson cautions. “If you don’t need a large volume, evaluate other nutrient sources or visit with neighbors to potentially share a load. The economics of poultry litter often hinges on transportation costs associated with delivery,” she adds.