Application of the denitrification-decomposition model to predict carbon dioxide emissions under alternative straw retention methods.
Straw retention has been shown to reduce carbon dioxide (CO2) emission from agricultural soils. But it remains a big challenge for models to effectively predict CO2 emission fluxes under different straw retention methods. We used maize season data in the Griffith region, Australia, to test whether the denitrification-decomposition (DNDC) model could simulate annual CO2 emission. We also identified driving factors of CO2 emission by correlation analysis and path analysis. We show that the DNDC model was able to simulate CO2 emission under alternative straw retention scenarios. The correlation coefficients between simulated and observed daily values for treatments of straw burn and straw incorporation were 0.74 and 0.82, respectively, in the straw retention period and 0.72 and 0.83, respectively, in the crop growth period. The results also show that simulated values of annual CO2 emission for straw burn and straw incorporation were 3.45 t C ha(-1) y(-1) and 2.13 t C ha(-1) y(-1), respectively. In addition the DNDC model was found to be more suitable in simulating CO2 mission fluxes under straw incorporation. Finally the standard multiple regression describing the relationship between CO2 emissions and factors found that soil mean temperature (SMT), daily mean temperature (T mean), and water-filled pore space (WFPS) were significant.
College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing, Jiangsu 210095, China ; Melbourne School of Land and Environment, The University of Melbourne, Melbourne, VIC 3010, Australia.
Can
C
Chen
Melbourne School of Land and Environment, The University of Melbourne, Melbourne, VIC 3010, Australia.
Deli
D
Chen
College of Resources and Environmental Sciences, Nanjing Agricultural University, Nanjing, Jiangsu 210095, China.
Jianjun
J
Pan
Melbourne School of Land and Environment, The University of Melbourne, Melbourne, VIC 3010, Australia.
Shu Kee
SK
Lam
D000383:Agriculture / Q000379:methods*; D001315:Australia; D001673:Biodegradation, Environmental; D002245:Carbon Dioxide / Q000032:analysis*; D003198:Computer Simulation; D018556:Crops, Agricultural / Q000737:chemistry* / Q000254:growth & development; D058440:Denitrification; D005308:Fertilizers; D017752:Greenhouse Effect; D006813:Humidity; D017745:Incineration; D008962:Models, Theoretical; D018517:Plant Roots / Q000737:chemistry; D018547:Plant Stems / Q000737:chemistry*; D012987:Soil; D013696:Temperature; D003313:Zea mays / Q000737:chemistry* / Q000254:growth & development
D005308:Fertilizers; D012987:Soil; D002245:Carbon Dioxide