52-6 Nitrogen Transformations in Manure Amended Soils As Affected By Biochar Application.

See more from this Division: ASA Section: Environmental Quality
See more from this Session: Symposium--Manure Management: Measuring and Mitigating Nutrient Losses and Gaseous Emissions

Monday, November 7, 2016: 10:15 AM
Phoenix Convention Center North, Room 228 B

James A. Ippolito, Colorado State University, Colorado State University, Fort Collins, CO, Rodrick D. Lentz, USDA-ARS, Kimberly, ID and Claudia Kammann, Department for Soil Science and Plant Nutrition / WG Climate Change Research for Special Crops, Hochschule Geisenheim University, Geisenheim, Germany
Abstract:
Localization of confined animal feeding operations (CAFOs) has brought about a massive production of animal manures. Traditional management practices have applied manure to crops as a fertilizer; yet long-term manure applications can cause nutrient imbalances (such as N) in soils far in excess of what crops can assimilate. As a repercussion, excess soil nitrogen (N) can leach into ground water or be lost as N2O. The situation is so severe in areas with multiple CAFOs, that producers must have nutrient management plans or manure application can be restricted if soils are over-saturated with respect to N. There is a clear need for alternative animal waste management methods with respect to N.

Biochar, a pyrolysis by-product, holds promise as a material that can influence soil N transformations in manure amended soils.  Biochar has been shown to both increase and decrease soil NO3-N concentrations when applied to manure amended soils.  However, given high enough biochar application rates, soil NO3-N may be maintained at lower concentrations in manure amended soils.  Increasing biochar application rates have also been shown to reduce soil NO3-N leaching (in some instances up to 75%), suggesting nitrate capture by biochar.  Furthermore, it has been speculated that biochars can sorb soil NH4-N, temporarily removing it from microbial processes.  This could be important when utilizing manure amended soils containing excessive organic N.

Applying compost and biochar has been shown to increase retention of fertilizer-applied N.  Biochar blending with manures and co-composting, or blending with liquid dairy wastes, has been shown to enhance the agronomic nutrient value of the final product while helping to reduce N2O emissions and improve plant productivity; biochar alone has, in some instances, also been shown to reduce soil N2O emissions.  Overall, biochar application to manure amended soils could potentially benefit producers who often observe excessive soil N accumulation.  Specific results and mechanisms will be discussed.

See more from this Division: ASA Section: Environmental Quality
See more from this Session: Symposium--Manure Management: Measuring and Mitigating Nutrient Losses and Gaseous Emissions

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