Ammonia Emissions from Site-Specific Variable Rate Nitrogen Applications in Cotton. (5518)
Authors:
M.J. Beene* - California State University, Fresno
C. Krauter - California State University, Fresno(Fresno, CA) D. Goorahoo - California State University, Fresno(Fresno, CA) B. Roberts - University of California Cooperative Extension
Abstract:
Precision agriculture is the term applied to the use of GPS for location and guidance of farm equipment in the field combined with GIS techniques to vary the
application of seed, fertilizer, and pesticides in a site-specific manner. These
precision agriculture practices allow the grower to match the yield potential of the soil in parts of the field as small as 10 square meters by adjusting the amount of seed and fertilizer applied to that area. The primary advantage is economic, as areas of the field with lower yield potential will only have the seed and fertilizer applied that are needed for those soil conditions. The advantage in regard to air quality is the reduction of the excessive amounts of nitrogen fertilizers being applied that may result in higher ammonia emissions. A nitrogen fertilizer trial in the southern part of the San Joaquin Valley was used to compare variable rate nitrogen application practices with conventional practices. Ammonia sampling was conducted before, during, and after the application, in an attempt to detect differences in ammonia emissions from the different nitrogen rates. The method utilized was active
chemical filter packs or denuders at various elevations up to 10 meters. The test was conducted in 2003 and 2004. Levels of ammonia monitored seemed to track with applied amounts of anhydrous ammonia fertilizer. After three or four days ammonia monitored in the plots were close to background levels.
Speaker Information: Matt Beene, California State University, Fresno, 5370 N.
Chestnut Ave., Fresno, CA 93740; Phone: 559-278-6784; E-mail:
Session Information: Monday, November 1, 2004, 9:00 AM-11:00 AM Presentation Start: 9:00 AM (Poster Board Number: 0404)
Keywords: Ammonia Emissions; Precision Agriculture; San Joaquin Valley; Nitrogen Application in Cotton
