Mineralization of Nitrogen from Biofuel By-products and Animal Manures Amended to a Sandy Soil

Abstract

Transformations of nitrogen (N) from poultry litter (PL), dairy manure compost (DMC), anaerobically digested fiber (ADF), Perfect Blend 7–2–2 (PB), a compost/litter mixture (C/L), dried distillers grains from ethanol production (DG), and mustard meal from biodiesel production (MM) applied to a Quincy fine sand were investigated in an incubation experiment over 210 days. The cumulative release totals of available N after 210 days were 61, 61, 56, 44, 29, 2, and –2% for the total N in MM, PB, DG, PL, C/L, DMC, and ADF, respectively. With application of MM and DG, ammonium (NH₄-N) accumulated initially in the soil with very little nitrification, possibly because of inhibition of nitrification related to chemical compounds in the amendments. Mineralization of organic N to NH₄-N and nitrate (NO₃-N) was relatively slow from MM- and DG-amended soils, indicating the potential for using biofuel by-products as slow-release N sources for plants.

Keywords:

• Biofuel by-products
• dairy manure compost
• distillers grains
• mineralization
• mustard meal
• nitrogen
• nutrient cycling
• poultry litter
• soil fertility

Acknowledgments

We thank Steven Vaughn, Ted Durfy, John Rico, and Perfect Blend LLC for providing the amendments used in the study. We also acknowledge Bill Boge, who provided invaluable laboratory assistance and support on this project.