Ammonia, methane, and nitrous oxide emission from pig slurry applied to a pasture in New Zealand.
Much animal manure is being applied to small land areas close to animal confinements, resulting in environmental degradation. This paper reports a study on the emissions of ammonia (NH3), methane (CH4), and nitrous oxide (N2O) from a pasture during a 90-d period after pig slurry application (60 m3 ha-1) to the soil surface. The pig slurry contained 6.1 kg total N m-3, 4.2 kg of total ammoniacal nitrogen (TAN = NH3 + NH4) m-3, and 22.1 kg C m-3, and had a pH of 8.14. Ammonia was lost at a fast rate immediately after slurry application (4.7 kg N ha-1 h-1), when the pH and TAN concentration of the surface soil were high, but the loss rate declined quickly thereafter. Total NH3 losses from the treated pasture were 57 kg N ha-1 (22.5% of the TAN applied). Methane emission was highest (39.6 g C ha-1 h-1) immediately after application, as dissolved CH4 was released from the slurry. Emissions then continued at a low rate for approximately 7 d, presumably due to metabolism of volatile fatty acids in the anaerobic slurry-treated soil. The net CH4 emission was 1052 g C ha-1 (0.08% of the carbon applied). Nitrous oxide emission was low for the first 14 d after slurry application, then showed emission peaks of 7.5 g N ha-1 h-1 on Day 25 and 15.8 g N ha-1 h-1 on Day 67, and decline depending on rainfall and nitrate (NO3) concentrations. Emission finally reached background levels after approximately 90 d. Nitrous oxide emission was 7.6 kg N ha-1 (2.1% of the N applied). It is apparent that of the two major greenhouse gases measured in this study, N2O is by far the more important tropospheric pollutant.
Sherlock
Robert R
RR
Soil Plant and Ecological Sciences Division, P.O. Box 84, Lincoln Univ., Canterbury, New Zealand.
Sommer
Sven G
SG
Khan
Rehmat Z
RZ
Wood
C Wesley
CW
Guertal
Elizabeth A
EA
Freney
John R
JR
Dawson
Christopher O
CO
Cameron
Keith C
KC
D000383:Agriculture; D000393:Air Pollutants / Q000032:analysis*; D000641:Ammonia / Q000032:analysis*; D000818:Animals; D008372:Manure; D008697:Methane / Q000032:analysis*; D009609:Nitrous Oxide / Q000032:analysis*; D012037:Refuse Disposal; D012987:Soil; D013552:Swine; D014835:Volatilization
D000393:Air Pollutants; D008372:Manure; D012987:Soil; D000641:Ammonia; D009609:Nitrous Oxide; D008697:Methane