Economics and impact of manure and composted manure on soil quality and yield compared to chemical fertilizer among potential bio-fuel crops

The objectives of this study were to determine if poultry litter applications at equal rates as inorganic commercial fertilizers to potential bio-fuel crops in Oklahoma result in differences in biomass yield and soil quality. Field experiments with bermudagrass (Cynodon dactylon L.) and sweet sorghum (Sorghum bicolor (L.) Moench) were established for 3 years in two different locations. Fresh litter was applied at 4 different rates with inorganic applied to match these rates on an N, P, and K basis. Additionally two degraded litters (alum treated and normal) were applied to match rate C's nitrogen (N) rate.Poultry litter and commercial fertilizer application at equal rates produced relatively no difference in soil nutrient concentration applied at equal rates and positive increases in soil physical properties with litter application. Differences in overall biomass yields were present in most years; poultry litter plant available N should be taken into account. Degraded litters possessed higher economic value and alum treatment decreased environment risk of P transport.