1. Farm-gate budget of energy crops: an experiment to assess changes in GHGs balance due to a land use change from grassland to short rotation coppice of poplar SIMONE SABBATINI 1,*,NICOLA ARRIGA 1, CLAUDIA CONSALVO 1, BENIAMINO GIOLI 2, GIORGIO MATTEUCCI 3, ALESSANDRO ZALDEI 2, DARIO PAPALE 1 1 Dept. for Innovation in biological, agro-food and forest systems, University of Tuscia, Via S. Camillo de Lellis, 01100 Viterbo, Italy 2 Institute of Biometeorology, Consiglio Nazionale delle Ricerche, Via G. Caproni 8, 50145 Firenze, Italy 3 Institute for Agricultural and Forestry Systems in the Mediterranean, Consiglio Nazionale delle Ricerche, Via Cavour 4-6, I-87036 Rende (CS), Italy * Corresponding author. E-mail address: simone.sabbatini@unitus.it Introduction Introduction Over the last decades European agriculture was subject to Land Use Change (LUC) from traditional cultivations and grasslands to crops for energy production. The main reasons for that are the rising in the prices of oil and the need to contrast global warming. The reduction in Green-House Gases emissions related to the cultivation of energy crops and due to the reduction of oil consumption, however, is balanced by the series of treatments required by biomass cultivations, that leads again to emissions of GHG. In the context of the GHG-Europe FP7 project we set-up an experiment to study a case of LUC from grassland to Short Rotation Coppice of poplar clones in central Italy. Materials and methods Materials and methods We placed three masts for EC measurements in Castel d’Asso, a rural region close to Viterbo (fig 1): two masts on two poplar SRC of different ages, and one on a reference site, a grassland representing the original land use (fig 2). Poplar are harvested every 2 years. Preliminary results Preliminary results Fluxes of Carbon in the three sites are illustrated in graph. 1. Fig.1 – sites location Fig.2 – EC setup over the grassland Furthermore, we measured soil respiration, CH 4 and N 2 O fluxes: the CO 2 through the use of a closed system of gas exchange (Li-8100); CH 4 and N 2 O fluxes were monitored taking gas samples from the soil in three consecutive moments with the closed chamber technique (fig. 3). Gas samples were then analysed for gas concentrations using a Gas Chromatograph. Fig.3 – collars for chambers measurements In order to compute the Farm-Gate Budget (FGB) of both the grassland and the poplar plantations, we needed to collect also ancillary data such as litter samples and biomass. Other variables that contribute to GHG budget such as management (tillage, fertilizations, irrigations, harvesting) and disturbances were also collected with the kind collaboration of the farmer. High-frequency measurements were paired with meteo data: temperature and soil water content profiles were installed in the three sites, while other sensors were mounted on the towers for collecting air characteristics and radiation variables. See tab 1 for a list of variables collected on every tower. SiteEcosystemEC setupTurb. fluxesSoil fluxesSoil meteoRadiationOther It-CA01SRC Gill r3 + LI7500 CO2, H20, energy CO2, N2O, CH4 SWC, Ts, SHF Swin, Swout, Lwin, Lwout, NetRad, PPFD Ta, RH; litter; manag. It-CA02Grassland Metek usa + LI7500A CO2, H20, energy CO2, N2O, CH4 SWC, Ts, SHFNetRad P; biomass; LAI; manag. It-Ca03SRC CSAT3 + LI7500 CO2, H20, energy CO2, N2O, CH4 SWC, Ts, SHF NetRad, PPFD Litter; manag. Tab 1 – Variables collected in the experiment Graph. 1 – Carbon fluxes in the three crops: It-CA01, It-CA02, It-CA03 (from top to bottom). Red arrow indicates the harvesting Towers started to collect data at different times. For poplar crop It-CA01 summer data show a strong uptake (negative values of Fc). Though irrigation practice, it’s clear that plants suffered for a drought stress in August. For the grassland, instead, the uptake of CO2 is registered in autumn and spring. It-CA3 poplar plantation was harvested on January 10 th, as indicated by the red arrow. Recent data from this site show the rapid increase in the uptake due to beginning of foliage. Some gaps are due to system failures. Conclusions Conclusions the experiment will go on until the harvesting of It-CA01, forecast for January 2013. At the end we will have data covering an entire rotation period. For collaboration proposal don’t hesitate to contact the corresponding author.