1. Greenhouse gas balance of cropland conversion to bioenergy poplar short rotation coppice.
- Author
-
Sabbatini, S., Arriga, N., Bertolini, T., Castaldi, S., Chiti, T., Consalvo, C., Djomo, S. Njakou, Gioli, B., Matteucci, G., and Papale, D.
- Subjects
GREENHOUSE gases ,CROPLAND conversion program ,BIOMASS energy ,POPLARS ,CROP rotation - Abstract
The production of bioenergy in Europe is one of the strategies conceived to reduce greenhouse gas (GHG) emissions. The suitability of the land use change from a cropland (REF site) to a short rotation coppice plantation of hybrid poplar (SRC site) was investigated by comparing the GHG budgets of these two systems over 24 months in Viterbo, Italy. Eddy covariance measurements were carried out to quantify the net ecosystem exchange of CO
2 (FCO ), whereas chambers were used to measure N2 2 O and CH4 emissions from soil. Soil organic carbon (SOC) of an older poplar plantation was used to estimate via a regression the SOC loss due to SRC establishment. Emissions from tractors and from production and transport of agricultural inputs (FMAN ) were modelled and GHG emission offset due to fossil fuel substitution was credited to the SRC site considering the C intensity of natural gas. Emissions due to the use of the biomass (FEXP ) were also considered. The suitability was finally assessed comparing the GHG budgets of the two sites. FCO was the higher flux in the SRC site (-3512 ± 224 g CO2 2 eq m-2 in two years), while in the REF site it was −1838 ± 107 g CO2 m-2 in two years. FEXP was equal to 1858 ± 240 g CO2 m-2 in 24 months in the REF site, thus basically compensating FCO , while it was 1118 ± 521 g CO2 2 eq m-2 in 24 months in the SRC site. This latter could offset -379.7 ± 175.1 g CO2 eq m-2 from fossil fuel displacement. Soil CH4 and N2 O fluxes were negligible. FMAN weighed 2 and 4% in the GHG budgets of SRC and REF sites respectively, while the SOC loss weighed 455 ± 524 g CO2 m-2 in two years. Overall, the REF site was close to neutrality in a GHG perspective (156 ± 264 g CO2 eq m-2 ), while the SRC site was a net sink of -2202 ± 792 g CO2 eq m-2 . In conclusion the experiment led to a positive evaluation of the conversion of cropland to bioenergy SRC from a GHG viewpoint. [ABSTRACT FROM AUTHOR]- Published
- 2015
- Full Text
- View/download PDF