Effects of Manure and Cultivation on Carbon Dioxide and Nitrous Oxide Emissions from a Corn Field under Mediterranean Conditions
2010
Heller, Hadar | Bar-Tal, A. (Asher) | Tamir, Guy | Bloom, Paul | Venterea, Rodney T. | Chen, Dong | Zhang, Yi | Clapp, C Edward | Fine, Pinchas
The use of organic residues as soil additives is increasing, but, depending on their composition and application methods, these organic amendments can stimulate the emissions of CO₂ and N₂O. The objective of this study was to quantify the effects of management practices in irrigated sweet corn (Zea mays L.) on CO₂ and N₂O emissions and to relate emissions to environmental factors. In a 3-yr study, corn residues (CR) and pasteurized chicken manure (PCM) were used as soil amendments compared with no residue (NR) under three management practices: shallow tillage (ST) and no tillage (NT) under consecutive corn crops and ST without crop. Tillage significantly increased (P < 0.05) CO₂ and N₂O fluxes in residue-amended plots and in NR plots. Carbon dioxide and N₂O fluxes were correlated with soil NH₄ concentrations and with days since tillage and days since seeding. Fluxes of CO₂ were correlated with soil water content, whereas N₂O fluxes had higher correlation with air temperature. Annual CO₂ emissions were higher with PCM than with CR and NR (9.7, 2.9, and 2.3 Mg C ha⁻¹, respectively). Fluxes of N₂O were 34.4, 0.94, and 0.77 kg N ha⁻¹ yr⁻¹ with PCM, CR, and NR, respectively. Annual amounts of CO₂–C and N₂O–N emissions from the PCM treatments were 64 and 3% of the applied C and N, respectively. Regardless of cultivation practices, elevated N₂O emissions were recorded in the PCM treatment. These emissions could negate some of the beneficial effects of PCM on soil properties.
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