Molodovskaya, Marina (Cornell University, BEE Department,
76, Riley-Robb, Ithaca, NY, 14853; Phone: 607-339-8644; Email:
mm433@cornell.edu)
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 25°C 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.