Effects of water content and N addition on potential greenhouse gas production from two differently textured soils under laboratory conditions

ABSTRACT

GHGs production and emission may vary depending on soil physical properties, water management and fertilization. Two paddy soils characterized by different texture were incubated to evaluate the impact of flooding (permanent or intermittent) and N addition on potential N₂O, CH₄ and CO₂ production and release into atmosphere and soil solution. Relationships with volumetric water content (VWC) and water filled pore space (WFPS) were evaluated. Overall, the finer clayey soil (CL) produced 58% more CH₄ than the coarser sandy soil (SA) and showed an earlier sink to source transition; the difference was lower with N addition. Permanent flooding favoured the amount of dissolved CH₄. SA produced more N₂O emissions than CL under permanent flooding (31.0 vs. 3.7%); an opposite pattern was observed for dissolved N₂O (16.4 vs. 52.7%). Fertilization increased N₂O emissions under dry conditions in CL and under flooding in SA.

Our findings showed that i) VWC had a larger influence on N₂O and CH₄ emissions than WFPS, ii) soil type influenced the gas release into atmosphere or soil solution and the timing of sink to source transition in CH₄ emissions. Further investigation on timing of fertilization and drainage are needed to improve climate change mitigation strategies.

KEYWORDS:

• N₂O
• CH₄
• CO₂ production
• soil texture
• VWC
• WFPS
• dissolved compounds

Acknowledgments

This work was founded by NV MARS BELGIUM SA (MARS FOOD) and Ministero delle Politiche Agrarie, Alimentari e Forestali of Italy (POLORISO project, D.M. 5337, 05/12/2011). We wish to thank Dr. Marcello Pagliai, Dr. Elisabetta Lupotto and Dr. Walter De Man for their constant support. We are grateful to the personnel from CREA-CI for sites access and collaboration. We also wish to thank Dr. Giuseppe Valboa (CREA-AA) for laboratory support.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This work was supported by the NV MARS BELGIUM SA (MARS FOOD) and Ministero delle Politiche Agrarie, Alimentari e Forestali of Italy; [POLORISO project, D.M. 5337, 05/12/2011].