Impact of Manure Incorporation on Greenhouse Gas Emissions in Semi-Arid Regions


Purpose

Gaseous emissions from animal feeding operations (AFOs) can create adverse impacts ranging from short-term local effects on air quality, to long-term effects due to greenhouse gas generation. This study evaluates gaseous emissions from manure application with differing times to incorporation. The purpose of the study is to identify ways to improve manure management and land application BMPs in semi-arid regions with a high soil pH.

What did we do?

Manure application and incorporation methods were evaluated in a field setting on a soil with high pH. Scraped dairy manure was surface applied at a rate of 50 tons/acre to a Millville silt loam. Incorporation events occurred immediately, 24hrs after application, 72 hrs after application, and no incorporation. Gaseous emissions were monitored using a closed dynamic chamber with a Fourier Transformed Infrared (FTIR) spectroscopy gas analyzer, which is capable of monitoring 15-pre-programmed gases simultaneously including ammonia, carbon dioxide, methane, nitrous oxide, oxides of nitrogen, and volatile organic compounds. Emissions were monitored for 15 days.

What have we learned?

Emissions for methane (CH4) and ammonia (NH3) stopped when the manure was incorporated. For methane, 33% of the emissions occurred within the first 24 hours, 61% within the first 72 hrs. For ammonia, 50% of the emissions occurred within the first 24 hours, 88% within the first 72 hours. Carbon dioxide (CO2) emissions were reduced, but continued at a baseline level after incorporation. Immediate incorporation reduced total CO2 emissions for the 15 days by approximately 50%. Incorporation within 24 hours and 72 hours, reduced total CO2 emissions for the 15 days by 40% and 18%, respectively. Based on this data, incorporation greatly reduces NH3, CH4, and CO2 emissions. Rapid incorporation is needed to have a meaningful impact on NH3 and CH4 emissions. Best management practices should emphasize the need for immediate incorporation.

(Click to enlarge the graphs below).

Cumulative emissions summary: ammonia, carbon dioxide, and methane

Future Plans  

Examine the impact of tannins on gaseous emissions.

Authors   

Rhonda Miller, Ph.D.; Agricultural Systems Technology and Education Dept.; Utah State University rhonda.miller@usu.edu

Pakorn Sutitarnnontr, Ph.D.; South Florida Water Management District; Naples, FL Markus Tuller, Ph.D.; Soil, Water, and Environmental Science Dept.; University of Arizona Jim Walworth, Ph.D.; Soil, Water, and Environmental Science Dept.; University of Ar

Additional Information

Sutitarnnonntr, P., E. Hu, R. Miller, M. Tuller, and S. B. Jones. 2013. Measurement Accuracy of a Multiplexed Portable FTIR- Surface Chamber System for Estimating Gas Emissions. ASABE 2013 Paper and Presentation No. 131620669. St. Joseph, MI: American Society of Agricultural and Biological Engineers.

Website: http://agwastemanagement.usu.edu

Acknowledgements      

The authors gratefully acknowledge support from a USDA-CSREES AFRI Air Quality Program Grant #2010-85112-50524.

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