Effects of Manure and Cultivation on Carbon Dioxide and Nitrous Oxide Emissions from a Corn Field under Mediterranean Conditions

Heller, Hadar; Bar-Tal, A.; Tamir, Guy; Bloom, Paul; Venterea, Rodney T.; Chen, Dong; Zhang, Yi; Clapp, C Edward; Fine, Pinchas

Effects of Manure and Cultivation on Carbon Dioxide and Nitrous Oxide Emissions from a Corn Field under Mediterranean Conditions

2010

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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