A six-year study at the University of Missouri’s Graves-Chapple Extension and Education Center in northwestern Missouri investigated the impact of poultry litter on soybean yields. According to Wayne Flanary, an MU Extension agronomy specialist who led the research, “Poultry litter is increasingly being applied to row crops in northwest Missouri. It is valuable for adding organic matter and essential nutrients such as nitrogen, phosphorus, and potassium.”
In the spring of 2018, ten tons of poultry litter were applied to each plot. The site, which had uneven topsoil due to leveling, saw the litter lightly incorporated with a disk. There were four replications of both the litter-treated and untreated control plots. In spring 2023, phosphorus fertilizer was applied across all plots. Analysis showed the poultry litter contained 60 pounds of nitrogen, 50 pounds of phosphate, and 27 pounds of potash per ton.
In 2023, soybean yields in the treated plots were generally higher, but the differences were not statistically significant, likely due to variability from uneven topsoil removal. Yields were 55.5 bushels per acre on plots with litter and minimal topsoil removal, compared to 51.6 bushels per acre on plots with severe topsoil scalping. Untreated plots yielded 49.1 and 35.3 bushels per acre, respectively.
Flanary concluded, “Manure is an effective management strategy for improving crop yields, particularly in eroded soils and areas with terrace channel cuts.”
Source: University of Missouri
