Molodovskaya, Marina (Cornell University, BEE Department, 76, Riley-Robb, Ithaca, NY, 14853; Phone: 607-339-8644; Email: mm433@cornell.edu)

 

The Effect of Aeration on Nitrous Oxide Emissions from Fresh Dairy Manure

 

M.S. Molodovskaya *, O. Singurindy, S.K. Giri, B.K. Richards, T.S. Steehuis

 

Nitrous oxide emissions from agriculture substantially contribute to the greenhouse effect and total available nitrogen loss. Though many previous studies have investigated N2O emissions from agricultural soils and manure storage facilities, very little is known about the potential for N2O formation and emissions from fresh land-applied dairy manure. Since nitrous oxide is formed as a subproduct of microbial nitrification/denitrification processes, the rate of emissions from fresh manure can be very high due to high total N and C initial content. N2O formation also strongly depends on oxygen availability.   The objective of this study was to estimate nitrous oxide emission from fresh dairy manure under different aeration rates. Samples of fresh manure (1.35g dry matter) mixed with distilled water (100 ml) were incubated at 25C for 15 days and aerated continuously with air at flow rates varied from 5, 45, and 90 mL g-1 min-1. The results have shown significant difference in N2O emissions, with the greatest emission of N2O-N correlating with the greatest airflow rate. The concentrations of other mineralized forms of nitrogen (nitrate, nitrite and ammonium as well as volatile ammonia emissions) were also measured and used to quantify the nitrogen
transformations.