LCA Food 2012 in Saint Malo, France! - Manifestations et colloques ...

PARALLEL SESSION 6B: FISHIERIES, SOIL, AND EMERGY METHODS 8 th Int. Conference on LCA in the
Agri-Food Sector, 1-4 Oct 2012
Mg SOM ha -1 , were converted into Mg CO2 ha -1 using a SOM/SOC ratio of 1.724 (van Bemmelen factor, in
Nelson and Sommers, 1982) and a C/CO2 molecular weight ratio of 3.66 (44 CO2/12 C g mole -1 ).
Case study
The study area was the hilly inland region in Southern Tuscany, Italy. Climate is typically Mediterranean,
characterised by two main rainy seasons in the autumn and the spring, a total annual rainfall of around
800 mm, and an average temperature of 14.5° C. Soils are quite variable with a texture ranging from silt
loam to clay. The main physical and chemical characteristics of the soil on the case study vineyard are reported
in Table 1.
Table 1. Soil parameter on the case study vineyard needed to run the model.
Soil parameter Unit Value
Sand (g/kg) 200
Silt (g/kg) 485
Clay (g/kg) 315
Limestone (g/kg) 0.00
Bulk density (g/cm 3 ) 1.30
Soil organic matter (g/kg) 1.19
The functional unit (FU) used for the study was one 0.75 L bottle of wine, and all data refers to the year
2009. The system boundary was divided into two main phases, the vineyard and the winery, and seven subphases,
including vineyard planting (1 year), pre-production sub-phase (3 years), production sub-phase (27
years), vinification, bottling, packaging and distribution.
Data on vineyard soil management, such as manure distribution, use of pruning residues and inter-row
vineyard grass cover or grassing was collected using specific questionnaires, while data relating to the physical
and chemical characteristics of the soil was provided by farmer in the form of soil samples collected at
the vineyard planting stage. CO2 emissions/removal caused by carbon stock changes in vine biomass were
not included, since its carbon pool is considerably smaller than that of soil, less than 1% (Keightley 2011),
and the corresponding vine biomass C pool is removed at the end of the vineyard production period. Direct
and indirect N2O soil emissions from synthetic and organic fertilisers were calculated using the IPCC methodology
and emissions factors (IPCC, 2006).
For this study, GWP impact was evaluated by considering the CO2, CH4 and N2O emissions associated
with energy and material inputs during each sub-phase of the production chain. Biogenic emissions were not
considered.
The baseline situation and four scenarios have been elaborated to assess the effect of crop management,
considering a decreasing levels of organic matter inputs, as follow:
S1: manure distribution at vineyard planting; inter-row grassing with cover crops; incorporation of
pruning residues into the soil;
S2: no manure distribution; inter-row grassing with cover crops; incorporation of pruning residues
into the soil;
S3: manure at vineyard planting; tillage for weed control; pruning residues removed;
S4: no manure distribution; tillage for weed control; pruning residues removed.
The values used in the scenarios are reported in Table 2.
Table 2. Values used in the baseline and in the scenarios to simulate the effect of vineyard management.
Treatment Unit Baseline S1 S2 S3 S4
Manure at planting Mg f.m. ha -1 20 65 0 65 0
Incorporation of pruning residues Mg d.m. ha -1 0 3.02 3.02 0 0
Inter-row grassing with cover crops Mg d.m. ha -1 0 4.5 4.5 0 0
3. Results
Table 3 shows the SOM pool evolution during the vineyard’s lifespan, from the vineyard planting to the
last productive year. For each sub-phase, the organic inputs and the organic outputs are reported, as well as
the intermediate SOM balance.
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