1,720,973 research outputs found
Potential role of compost and green manure amendment to mitigate soil GHGs emissions in Mediterranean drip irrigated maize production systems
No full textOrganic fertilization can preserve soil organic matter (SOM) and is foreseen as an effective strategy to
reduce green house gases (GHGs) emissions in agriculture. However, its effectiveness needs to be clarified
under specific climate, crop management and soil characteristics. A field experiment was carried out
in a Mediterranean drip irrigated maize system to assess the pattern of soil CO2 and N2O fluxes in
response to the replacement of a typical bare fallowemaize cycle under urea fertilization (130 kg N ha1
y1) (CONV) with: (i) bare fallow-maize cycles under two doses of compost (COM1 and COM2, 130 and
260 kg N ha1 y1, respectively) and (ii) a vetch-maize cycle, with vetch incorporation as green manure
(130 kg N ha1 y1) (GMAN).
Along the maize period (MP), reduced daily N2O emissions were detected in organic treated soils
compared to CONV, mainly in the first stages of the cultivation, thanks to the slow release of available
nitrogen from the organic substrates. Cumulative N2O fluxes (kg N2O-N ha1) in MP scored to 0.24, 0.14,
0.12 and 0.085 for CONV, COM1, COM2 and GMAN, respectively, with significantly lower emissions in
GMAN respect to CONV. CO2 fluxes partially reflected the ranking observed for maize yields, with
cumulated values (Mg CO2-C ha1) of 2.2, 1.5, 2.1, 2.1 for CONV, COM1, COM2 and GMAN, respectively,
and significantly lower in COM1 respect to the other treatments.
During the fallow period (FP), compared to CONV (0.77 Mg CO2-C ha1 and 0.25 kg N2O-N ha1),
enhanced GHG fluxes were detected in COM treatments (about 0.90 Mg CO2-C ha1 and 0.37 kg N2O-N
ha1, as averaged values from COM1 and COM2), likely driven by the slow prolonged mineralization of
the added organic matter. GMAN showed comparable CO2 (0.82 Mg CO2-C ha1) and N2O emissions
(0.30 kg N2O-N ha1), in consequence of restrained post-harvest residual N coupled with the counteracting
effect of vetch uptake.
Respect to the total yearly GHG emissions in CONV (about 194 kg CO2 eq ha1 y1), the overall results
showed commensurate slightly higher GWP in COM treatments (þ11% as averaged value from COM1 and
COM2). The yield-scaled global warming potential (GWP) resulted 60% higher and nearly doubled for
COM2 and COM1 respectively, according to the lower COM yields, markedly dampening at halved
compost dose. GMAN appeared the best performing organic treatment, with lower GWP (27%) and
competitive yields respect to CONV.
All treatments showed N2O emission factors consistently lower compared with the default IPCC 1%
value
Carbon footprint of heliciculture: A case study from an Italian experimental farm
No full textHeliciculture for food production has huge potential and newopportunities for rural development and young entrepreneurs
in Italy. No studies have yet been performed on the environmental performance of snail rearing
which also might be a bene!cial tool for producers. The aim of the present paper is to evaluate the impact of
snail meat by a cradle-to-farm gate life cycle assessment centred on the carbon footprint (CF).
The study considered greenhouse gas (GHG) emissions linked to cultivation stages (indoor breeding, outdoor
fattening, cleaning out and packaging) of Helix aspersa maxima meat production in a semi-intensive rearing system
in Southern Italy. The shell potential for CO2 sequestration was also taken into account.
Snail CF amounted to 0.7 kg CO2 eq per kg fresh edible meat, with the highest share (about 60%) from the supplementary
feeding production. Due to the combined effect of relevant amount input and restrained lifetime of
HDPE mesh applied in the open !eld, the impact of breeding enclosures appeared considerable (about 29%).
Greenhouse gas emissions linked to fodder cultivation and to the cleaning-out phase appeared restrained (nearly
4% and 5%, respectively), whilst the share of reproduction system, irrigation and packagingwas negligible (b1%).
The environmental load of supplementary feeding resulted to mainly ascribable (about 74%) to maize and !eld
bean grain cultivation (for feed mixture). It was followed by grain transport (about 17%) and processing
(about 4%) to feed mill and further transport of manufactured feed components (maize–!eld bean–limestone)
to the snail farm (about 5%). The CF score might be reduced by 18%, including potential long term CO2 sequestration
in shells. As compared to other conventional macro-livestock meat sources, snail meat showed reduced GHG
emissions
Effects of urea-fertilization rates on the environmental performance of giant reed lignocellulosic feedstock produced for biorefinery purpose
No full textA life cycle assessment (LCA) was carried out to investigate the environmental constrains of Arundo donax L. (common name giant reed) feedstock cultivation, for biorefinery purpose, treated with different amount of nitrogen fertilizations: 50 and 100 kg ha−1 of N as urea (low input- LI and high input- HI, respectively). The analysis was addressed for a cultivation of giant reed (GR) under Mediterranean conditions, considering primary data for the first eight years of cultivation and further modeled for the whole life cycle (15 years). The goals were, to ascertain and compare the environmental profile as well as to identify the hotspots for both investigated N- management techniques.
Results highlighted a potential higher environmental performance for the LI giant reed cultivation, due to the reduced up-stream and direct field emissions linked to urea application. LI impacts resulted to be 24% lower than HI impacts, as averaged values for all impact categories. Crop yield represented a driving parameter and the lower biomass productivity under N low input management partially counteracted the entailed benefits of the lower fertilization rates. Through the inclusion of soil carbon storage, after seven years of harvesting, the whole crop phase revealed a net greenhouse gases sink and also differences between LI (−0.21 kg CO2 eq) and HI (−0.09 kg CO2 eq) appeared amplified. This was due to the enhanced C accumulation rate in LI trials (about 7.7 ton C ha−1 at the end of the seventh harvest year of GR cultivation), likely promoted by reduced soil organic matter mineralization at lower nitrogen availability. Nevertheless, in order to provide a full and comprehensive picture of the environmental performance of GR feedstock under different N-fertilization, further studies are needed encompassing the whole production chain: from the cultivation, through selected efficient conversion processes towards the co-production of added value products in the framework of the BioPoliS project
Life Cycle Assessment of second generation bioethanol produced from low-input dedicated crops of Arundo donax L
No full textThis work presents a Life Cycle Assessment (LCA) of bioethanol (EtOH) from perennial Arundo donax L. feedstock. A “cradle-to-wheel” approach was applied considering primary data for the cultivation of dedicated crops on hilly marginal lands and innovative “second generation technologies” for feedstock conversion into EtOH. The goals of the study were to: (i) quantify impacts of lignocellulosic EtOH production/use chain, (ii) identify hotspots and (iii) compare the environmental performance of different bioethanol-gasoline vehicles, E10 (10% EtOH and 90% gasoline) and E85 (85% EtOH and 15% gasoline), with a conventional gasoline passenger car. Results for E85 underlined that the feedstock production and the use phase were the prevailing contributors, whilst for E10 the gasoline production phase shared the largest part of impacts. The comparison showed that vehicles using lignocellulosic bioethanol have potentially significant benefits on global warming, ozone depletion, photochemical oxidant formation and fossil depletion in respect to conventional passenger car
Environmental performance of maize crop subjected to different agricultural management: conventional, compost and green manure
No full textLife Cycle Assessment of maize cropping under different fertilization alternatives
No full textA Life Cycle Assessment was performed to compare the environmental impacts generated by Mediterranean maize crops (Southern Italy) under conventional management and C-friendly management aimed to preserve soil organic matter and reduce mineral N fertilizers application. Primary data from three fertilizing practices were processed: urea (CONV, conventional), compost (COM) and green manure (GMAN) distribution. Suitable comparisons among treatments were carried out by adopting the same system boundary (one hectare of cropped land) and functional unit (1kgmaize dry matter). Direct field emissions were calculated and the short term soil carbon storage, experimentally derived for COM and GMAN, was also included. Results indicate that the highest impacts are from chemical fertilizers over the background industrial supply chain. GMAN showed the lower environmental burdens, while soil protection strategy expected for COM appeared not sustainable, due to the low crop yield achieved
Environmental loading of Italian semi-intensive snail farming system evaluated by means of life cycle assessment
No full textIn the recent years, heliciculture has rapidly developed in Italy both in terms of number of companies
(about 8000) and average extension of snail farms (5000e10,000 m2). Studies aimed to evaluate the
whole environmental performance of heliciculture are still not available in literature. This paper presents
a Life Cycle Assessment (LCA) performed for Helix aspersa maxima snail production in the South of Italy.
The system boundary (cradle to farm gate) of the production chain considered the following stages:
indoor breeding, outdoor fattening, cleaning out and packaging. The outdoor fattening displayed the
largest part of total burdens (about 90%) for all impact categories due to the relevant contribution of its
processes (enclosures set-up, fodder cultivation, supplementary feeding and irrigation). The process that
highly affected all impact categories was the supplementary feeding used in fattening pens which
reached the highest value for Terrestrial acidification (84%) and the lowest one for Ozone depletion (41%).
Nevertheless, the impact of enclosures set-up and fodder cultivation appeared marked in particular for
Ozone depletion (46%) and Marine Eutrophication (30%), respectively.
Results showed the key factors (supplementary feeding, HDPE mesh) to be considered and discussed
to proper design a semi-intensive snail management in order to enhance benefits and constrain
limitations.
Moreover, the snail farming highlighted a lower environmental load, for almost all impact categories,
compared to literature data on conventional meat (beef, pig and chicken)
Comparison between conventional and minimum tillage for a Mediterranean maize crop by means of the LCA approach
No full textMitigation impact of minimum tillage on CO2 and N2O emissions from a Mediterranean maize cropped soil under low-water input management
No full textReduced tillage might reduce greenhouse gas (GHG) emissions from cropped soils. However the topic is
somehow still controversial, since lower CO2 emissions achieved through reduced soil mineralization
might be offset by higher N2O losses from less disturbed soil, because of higher water
filled pore space.
This work aimed to clarify the potential GHG mitigation benefits of minimum tillage (MT), as opposed to
mouldboard ploughing (CT), for Mediterranean maize cultivations under low water input management.
To this end, soil CO2 and N2O fluxes were monitored at high time resolution by means of a newly
developed automated system of closed static chambers coupled to a field gas photoacoustic detector.
Relative to CT, cumulated CO2 emissions appeared significantly reduced in MT over three months after
the autumn ploughing (by about 30%) and along the spring-summer cultivation (by about 28%), for
similar maize yields. N2O emissions from MT showed restrained averaged values relative to CT (by 40%
and 18% for fallow and maize periods, respectively); however differences might not be significant. For
both treatments, N2O emission factors were lower than the 1% IPCC default value (0.40 and 0.28 for CT
and MT, respectively), following the restrained irrigation water input along the drought period. Results
indicate that MT reduced GHG emissions both (i) in the short-term, likely due to the increased
decomposition of soil organic matter in the ploughed soil (CT), mainly concentrated within the
first week after deep tillage; (ii) in the longer-term, likely through its capacity to constrain the daily soil
temperature fluctuations in the drought periods along the spring-summer maize cultivation. At this
stage, the low-water input management might have played a key role in mediating the response of N2O
emissions to MT treatment.
These findings suggest that minimum tillage could entail consistent GHG benefits under the drip
irrigation management in Mediterranean croplands
LCA of 1,4-Butanediol Produced via Direct Fermentation of Sugars from Wheat Straw Feedstock within a Territorial Biorefinery
No full textThe bio-based industrial sector has been recognized by the European Union as a priority
area toward sustainability, however, the environmental profile of bio-based products needs to be
further addressed. This study investigated, through the Life Cycle Assessment (LCA) approach, the
environmental performance of bio-based 1,4-butanediol (BDO) produced via direct fermentation of
sugars from wheat straw, within a hypothetical regional biorefinery (Campania Region, Southern
Italy). The aim was: (i) to identify the hotspots along the production chain; and (ii) to assess the
potential environmental benefits of this bio-based polymer versus the reference conventional product
(fossil-based BDO). Results identified the prevailing contribution to the total environmental load of
bio-based BDO in the feedstock production and in the heat requirement at the biorefinery plant. The
modeled industrial bio-based BDO supply chain, showed a general reduction of the environmental
impacts compared to the fossil-based BDO. The lowest benefits were gained in terms of acidification
and eutrophication, due to the environmental load of the crop phase for feedstock cultivation
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