But farmers in Mississippi and other southern states are applying litter at the wrong time of time, according to a U.S. Department of Agriculture (USDA) agronomist.
Farmers in Mississippi often apply poultry litter in the fall, months before planting cash crops in the spring, because it's cheaper then and they have more time than in the spring, but Haile Tewolde at Mississippi State has found that spring is the optimal season for applying litter in the South and Southeast.
Tewolde and his colleagues applied poultry litter in the spring and fall to test plots of corn planted each April for three years. They applied the litter at two rates - four tons per acre and eight tons per acre - and incorporated it into the soil by "disking," a process that turns the soil and pulverizes it so that the litter blends in with the soil. For comparison, the researchers applied nitrogen fertilizer to other test plots in the spring and fall.
The results showed that over three years, yields were cumulatively higher in plots with litter applied in the spring than in the fall, regardless of the application rate. At the four-ton rate, spring-application yields were 16.7 percent higher, and at the eight-ton rate, they were 12.8 percent higher.
The results also showed that while using litter produced less corn than using fertilizer in the first year, those results were reversed in the second and third years. Higher yields in the second and third years were likely because nitrogen in the litter applied during the first year stayed in the soil and benefited crops in subsequent years.
Source: Agricultural Research ServicePlants and Seeds
Artwork: Manure Spreading