Nitrous oxide emissions from maize-wheat field during 4 successive years in the North China Plain

Abstract

Agricultural soil with fertilization is a main anthropogenic source for atmospheric nitrous oxide (N2O). N2O fluxes from a maize-wheat rotation field in the North China Plain (NCP) were investigated for 4 successive years using the static chamber method. The annual N2O fluxes from the control (without fertilization) and fertilization plots were 1.5±0.2 and 9.4±1.7 kgN ha-1 yr-1 in 2008-2009, 2.0±0.01 and 4.0±0.03 kgN ha-1 yr -1 in 2009-2010, 1.3±0.02 and 5.0±0.3 kgN ha -1 yr-1 in 2010-2011, and 2.7±0.6 and 12.5±0.1 kgN ha-1 yr-1 in 2011-2012, respectively. Annual direct emission factors (EFd 's) in the corresponding years were 2.4±0.5 %, 0.60±0.01 %, 1.1±0.09% and 2.9±0.2 %, respectively. Significant linear correlation between fertilized-induced N 2O emissions (Y , kgN ha-1) during the periods of 10 days after fertilization and rainfall intensities from 4 days before to 10 days after fertilization (X, mm) in the 4 years was found as Y = 0.048X-1.1 (N = 4, R 2 = 0.99, P.© Author(s) 2014. CC Attribution 3.0 License.