Modeling nitrous oxide emissions from irrigated agriculture: testing DayCent with high‐frequency measurements

Abstract

A unique high temporal frequency data set from an irrigated cotton-wheat rotation was used to test the agroecosystem model DayCent to simulate daily N20 emissions from subtropical vertisols under different irrigation intensities. DayCent was able to simulate the effect of different irrigation intensities on N20 fluxes and yield, although it tended to overestimate seasonal fluxes during the cotton season. DayCent accurately predicted soil moisture dynamics and the timing and magnitude of high fluxes associated with fertilizer additions and irrigation events. At the daily scale we found a good correlation of predicted vs. measured N20 fluxes (r2 = 0.52), confirming that DayCent can be used to test agricultural practices for mitigating N20 emission from irrigated cropping systems. A 25-year scenario analysis indicated that N20 losses from irrigated cotton-wheat rotations on black vertisols in Australia can be substantially reduced by an optimized fertilizer and irrigation management system (i.e., frequent irrigation, avoidance of excessive fertilizer application), while sustaining maximum yield potentials.

Evaluating four nitrous oxide emission algorithms in response to N rate on an irrigated corn field

“…The emission factor (EF, a ratio of the difference in N 2 O emissions between N treatment and none N treatment to the applied N rate) ranged from 0.65 % to 0.72 % for measured data and from 0.43% to 0.95% for the simulated data, and both measured and simulated data showed an increase in EF with N application rates ( Table 6). The EF values were lower than the 1% value suggested by IPCC method (IPCC, 2006a), and similar results for measured and simulated EF below 1% were also reported for a cotton-wheat rotation system in Australia using DAYCENT model (Scheer et al, 2014). The above result indicates that the IPCC method is the worst scenario to calculate soil potential N 2 O emissions from applied N, in spite of high uncertainty (À70%e200%, IPCC, 2006b).…”

Underestimation of N2O emissions in a comparison of the DayCent, DNDC, and EPIC models

“…, Scheer et al. , Álvaro‐Fuentes et al. ), whereas DNDC has underestimated peak fluxes (Smith et al.…”

Daycent Simulation of Methane Emissions, Grain Yield, and Soil Organic Carbon in a Subtropical Paddy Rice System

“…The model has been widely tested in upland soils (Plaza-Bonilla et al, 2014;Scheer et al, 2014;Congreves et al, 2015;Migliorati et al, 2015;Weiler et al, 2017). The model includes submodels for plant yield, crop residues and organic matter, soil water and temperature dynamics, and C and N gas fluxes.…”