Nitrous Oxide Emission by Piedmont Soil as Influenced by Fertilizer and Cover Crop Management. (6225)
Authors:
N. Fernando* - NC A&T State Univ M.R. Reddy - NC A&T State Univ V. Shirley - NC A&T State Univ
Abstract:
Nitrous oxide (N2O) is a greenhouse gas which contributes to global warming. The N2O flux from the soil is regulated by the interaction of abiotic and soil management factors. A field experiment was conducted at the Piedmont Complex for Agricultural Research and Extension Demonstration in North Carolina to estimate N2O flux from a Piedmont soil under cover crop and N rates. The soil on the experimental site is Mecklenburg sandy loam (fine, mixed, thermic Ultic Hapludalfs). In a split-plot design, crop residue amendment and the fertilizer N level were arranged as main and sub plot factors, respectively. Winter cover crops, Crimson clover (Trifolium incarnatum L.) and Cereal Rye (Secale cereale L.) were grown as mixed stand and mowed and specialty melons (Cucumis melo L.) were transplanted in the plots. The selected two N fertilizer rates were 0, 72.5 and 145 kg N ha-1 applied in split applications through fertigation. Gas samples were collected from static chambers in the field plots and analyzed for N2O using gas chromatography. Nitrous oxide flux was higher at 72.5 kg N ha-1 than at 145 kg N ha-1 in plots with no residue amendment while it was the opposite in residue added plots.
In general, N2O flux was greater in residue amended plots than with no residue amendment. Variability in N2O flux could be explained by the differences in soil moisture, temperature and available N.
Speaker Information: Nishantha Fernando, NC A&T State Univ, Dept of Natural Resources & Env Design NC A&T State University, Greensboro, NC 27411; Phone: (336)334-7573; E-mail: [email protected]
Session Information: Thursday, November 4, 2004, 10:40 AM-12:00 PM Presentation Start: 11:15 AM
Keywords: Nitrous oxide; Cover crops; Fertilizer; Piedmont soil
