| Autor: |
A.R. Mosier, Dennis S. Ojima, Melannie D. Hartman, S. J. Del Grosso, William J. Parton, C.A. Keough, David S. Schimel, Gary A. Peterson |
| Rok vydání: |
2001 |
| Předmět: |
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| Zdroj: |
Nitrogen in the Environment: Sources, Problems and Management |
| DOI: |
10.1016/b978-044450486-9/50018-2 |
| Popis: |
This chapter discusses simulated effects of land use; soil texture; and precipitation on N gas emissions using DAYCENT. The chapter describes the N gas flux submodel used in the DAYCENT ecosystem model and demonstrates the ability of DAYCENT to simulate the low N gas emissions observed from native soils, the intermediate emissions associated with dryland agriculture, and the high emissions observed for irrigated agricultural soils. DAYCENT has been used to compare N gas emissions from soils for native range grass, winter wheat conventional till and no till, winter wheat/corn/fallow no till, irrigated corn and irrigated silage cropping. NO x made up the majority of N gas fluxes in all cases followed by N 2 O and N 2 . Soil water inputs, tillage, timing of crop/fallow periods, and fertilizer application interact to control N gas emissions so generalizations regarding land use are difficult to make. Switching to no till without changing the winter wheat cropping schedule resulted in higher N 2 O emissions because the increased soil water content induced by no till supported higher denitrification rates. Finally, the soil water savings associated with no till also allows a reduction in the fallow period and the 3-year winter wheat rotations had lower N 2 O and NO x emissions than the 2-year winter wheat/fallow systems considered. |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
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