Poultry litter being incorporated into the soil during disking, a process that turns the soil and pulverizes it so that the litter will be mixed into it. Over a 3-year period, ARS scientists determined that yields were cumulatively higher in plots with litter applied in the spring rather than in the fall.
(Photo by Haile Tewolde)
Poultry litter (chicken manure, spilled feed, excess feathers, and other poultry-house materials) contains nitrogen and phosphorus—both important crop nutrients. Applying poultry litter to the soil also recycles some of the tons of litter generated annually by poultry operations throughout the United States, says Haile Tewolde, an ARS agronomist at Mississippi State.
While more farmers are using poultry litter as fertilizer these days, there is little information about the amounts cotton growers should use to maximize profits.
Tewolde and his colleagues applied poultry litter to cotton at seven different rates on two farms by scattering the litter with a commercial fertilizer spreader. They measured cotton lint yields for three years at one farm and five years at another. For comparison, they also measured yields where they applied standard rates of synthetic fertilizer. They factored in the costs for the litter and the market price of the cotton to determine optimal rates for earning a profit.
The researchers found that the most profitable rate is not the same as the rates that produced the highest yields because of cotton’s current low cost. Maximum yields were achieved at 9,000 to 12,000 pounds of litter applied per acre. Yet, profits were highest at only 7,000 pounds applied per acre.
The results give growers specific recommendations to avoid applying more litter than needed, which could pollute waterways. The results also highlight poultry litter’s capabilities as a fertilizer.
Read more about this research in the March 2017 issue of AgResearch magazine.
For more information contact Dennis O’Brien, ARS Office of Communications.