1,721,148 research outputs found
Scanner based image analysis to characterise the influence of agronomic factors on hemp (Cannabis sativa L.) fibre width
No full textThe potential of industrial hemp to satisfy the increasing demand for natural products is limited by the lack of accurate information on how to measure and control bast fibre quality. A number of research projects have been carried out to study how hemp fibre yield is affected by genotype X environment X management (GXEXM) interaction, however the possibility to study how GXEXM affects fibre quality is hampered by the lack of standard analytical methods that can relate fibre traits, relevant to specific end use applications, to cultivation factors. In this paper an innovative methodology to analyse bast fibre quality (i.e. fibre finessess) is presented and discussed. In particular, fibre is chemically extracted (following the Bredemann method), then mechanically opened with a coarse separator and finally fibres and fibre bundle width is determined with an automated image analysis system (Fibershape). Evaluation of fibre width with this system provided results in agreement with fibre cell diameter measurements carried out on fresh stem cross section. Being fast and cost efficient this method provides researchers with a powerful system to measure the effect of agronomic techniques (i.e. sowing density and harvesting time), plant portion, genotype and potentially retting or other post-harvest managements of the stem on fibre width, which is considered one of the most important quality traits in bast fibre
Characterization of fine root system and potential contribution to soil organic carbon of six perennial bioenergy crops
No full textPerennial bioenergy crops provide biomass for renewable energy production, but also sequester atmospheric carbon (C) in the soil. Roots represent one of the most important soil C inputs-root length density (RLD, cm cm-3), root diameter and fine root biomass (FRB, Mg ha-1) in the top 1 m of soil were characterized for three woody (poplar, black locust, willow) and three herbaceous (giant reed, miscanthus, switchgrass) perennial crops in the same location. The vertical distribution of FRB and RLD was described by fitting the "beta" (Î2) model to the experimental data. The herbaceous species had higher Î2 values for FRB and RLD than woody crops, suggesting that the former explore the deeper soil layers with a greater proportion of roots. In particular, 3.7 Mg ha-1, or 43% of the whole root mass, was found below the ploughing soil layer (0.3 m) for the herbaceous species, while only 1.2 Mg ha-1, or 26% of the whole root mass, was allocated by woody crops to the same soil layer. In all the species, the majority of the sampled roots (99.1%) had a diameter lower than 2 mm, and in the first 10 cm of the soil the woody species tended to produce roots with a smaller diameter than those of the herbaceous species. Overall, the herbaceous crops have a higher potential to contribute to C storage in the deep soil layers, while the woody species, have a greater potential to affect soil organic carbon in the top soil layer
Hemp - Cultivation, Extraction and Processing
No full textHemp (Cannabis sativa L.) is a multiuse, multifunctional crop that can provide valuable raw
material to a large number of no-food industrial applications. The environmentally friendly
cultivation and the sustainability of its products are the main drivers for a future expansion of the
hemp crop. In this chapter we will tackle the main technical issues encountered along the hemp
production chains, from cultivation to fibre processing, for its utilization in textile (longitudinal)
and non textile (disordered) applications
Mitigating the environmental impacts of milk production via anaerobic digestion of manure: Case study of a dairy farm in the Po Valley
No full textThis work analyzes the environmental impacts ofmilk production inan intensivedairyfarmsituated in theNorthern
Italy region of the Po Valley. Three manure management scenarios are compared: in Scenario 1 the animal slurry is
stored in an open tank and then used as fertilizer. In scenario 2 the manure is processed in an anaerobic digestion
plant and the biogas produced is combusted in an internal combustion engine to produce heat (required by the digester)
and electricity (exported). Scenario 3 is similar to scenario 2 but the digestate is stored in a gas-tight tank.
In scenario 1 the GHG emissions are estimated to be equal to 1.21 kg CO2 eq. kg−1 Fat and Protein Corrected Milk
(FPCM) without allocation of the environmental burden to the by-product meat.With mass allocation, the GHG
emissions associated to the milk are reduced to 1.18 kg CO2 eq. kg−1 FPCM. Using an economic allocation approach
the GHG emissions allocated to the milk are 1.13 kg CO2 eq. kg−1 FPCM. In scenarios 2 and 3, without allocation,
theGHGemissions are reduced respectively to 0.92 (−23.7%) and 0.77 (−36.5%) kg CO2 eq. kg−1 FPCM.
If land use change due to soybean production is accounted for, an additionalemission of 0.53 kg CO2 eq. should be
added, raising the GHG emissions to 1.74, 1.45 and 1.30 kg CO2 eq kg−1 FPCMin scenarios 1, 2 and 3, respectively.
Primary energy from non-renewable resources decreases by 36.2% and 40.6% in scenarios 2 and 3, respectively,
with the valorization of the manure in the biogas plant.
The other environmental impact mitigated is marine eutrophication that decreases by 8.1% in both scenarios 2
and 3, mostly because of the lower field emissions.
There is, however, a trade-off between non-renewable energy and GHG savings and other environmental impacts:
acidification (+6.1% and +5.5% in scenarios 2 and 3, respectively), particulate matter emissions (+1.4% and
+0.7%) and photochemical ozone formation potential (+41.6% and+42.3%) increase with the adoption of a biogas
plant.The causeof the increase ismostlyemissions fromtheCHPengine.These impacts canbe tackledbyimproving
biogas combustion technologies to reducemethane andNOx emissions. Freshwater eutrophication slightly increases
(+0.8% in both scenarios 2 and 3) because of the additional infrastructures needed.
In conclusion, on-farm manure anaerobic digestion with the production of electricity is an effective technology to
significantly reduce global environmental impacts of dairy farms (GHG emissions and non-renewable energy consumption),
however local impacts may increase as a consequence (especially photochemical ozone formation)
A meta-analysis of bioenergy conversion relevant traits in sorghum landraces, lines and hybrids in the Mediterranean region
No full textSorghum crop demonstrated high yield potential under drought and wet environments with a betterenergy balance than several cultivated plants. Sorghum biomass can contribute to solving the pressingissue of reducing reliance on fossil fuel. Africa and Asia are sorghum centers of diversity, and landracestherefrom can be of great breeding and production interests in the Mediterranean region. Several worksevaluated biomass sorghums, but results on comparative performance between lines, landraces andhybrids are lacking. The objective of this work was to assess the performance of these genotypic groupsfor traits relevant for biofuel conversions, by carrying out a meta-analysis of data from twenty-fourtrials conducted in different Mediterranean locations in Italy over seven years. Obtained results showedsorghum hybrids as the best biofuel feedstock option as they outperformed landraces and lines for mosttraits including biomass yield. Landraces represented an attractive alternative to hybrids and lines as theyoutyielded lines and were second only to hybrids in terms of biomass production and cellulosic content.Biomass yield advantage was explained by increased plant tallness and cellulosic content in hybrids,and cellulosic content in landraces, and to a lesser extent, by plant maturity in hybrids and landraces.Based on biomass quality and quantity, hybrids and landraces can supply thermal, thermochemical andbiochemical biofuel conversion industries. Sorghum lines could be better used in first generation biofueland energy bioconversion technologies requiring lower lignin containing feedstocks. Landraces and linescould be targeted to areas where hybrid seed production industry is not developed
Cultivation of biomass sorghum for second generation ethanol production
No full textSorghum (Sorghum bicolor L.) is a very interesting biofuel feedstock crop. With C4 photosynthesis
and drought tolerance, it is suitable for cultivation in water limited environments and could be a key crop in a warmer
and unpredictable global climate. Furthermore, sorghum can be used for ethanol production from both 1st and 2nd
generation technologies (using sweet/grain genotypes or biomass genotypes, respectively).
The potential use of commercial sorghum genotypes for the production of 2nd generation ethanol was investigated in
a two year project in Northern Italy. Fields trials were carried out for two years in two locations on a selection of
genotypes to optimize agronomical technique, identifying in particular the effect of plant density, irrigation,
fertilization, time of harvesting on crop yield. Biomass compositions were analysed for all genotypes while ethanol
yield was estimated on three genotypes at harvest and after conservation. Pretreatment, hydrolysis and fermentation
were carried out with the innovative technology developed by Chemtex.
Biomass yield was on average 22.6 Mg ha-1, with large differences among genotypes, environments and cultivation
techniques so that extreme yield of 10.6 and 38.4 Mg ha-1 were measured.
Percentage of fermentable sugars on dry matter in the genotypes under trial varied from 47% to 60%, and glucans
were on average 63% of the fermentable sugars in both years. Average Klason lignin and acetyl content were,
respectively, 12.8% and 1.7%. Biomass composition varied significantly among genotypes.
The test carried out on biomass preserved by on field drying or silage showed that the latter method results in high
ethanol yield reduction and is therefore not a suitable option for sorghum conservation.
In general biomass sorghum can be considered an interesting crop for 2nd generation ethanol production.
Keywords: Sorghum bicolor, 2nd generation ethanol, cultivation, processing, conservation
Soil and ecosystem services: Current knowledge and evidences from Italian case studies
No full textSoil management is fundamental to all agroecosystems and affects ecosystem processes that are involved in the provision of multiple ecosystem services (ES). Agricultural soils are the habitat for key functional organisms which collectively as soil biota contribute to soil ES provision: supporting biomass production and nutrient cycling, regulating of climate, water and biological control of pests and diseases. As result of an increased awareness on the importance of soil ES, soil science is playing an active role in informing the ecological intensification of agriculture. In this study, the lessons learned from Italian case studies on the usefulness of using a soil health assessment framework based on multiple soil ES are presented. Soil health as an integrative property of agroecosystem management can be evaluated with a set of physical, chemical, and biological indicators representative of essential soil ES. This is the basis of the Soil Management Assessment Framework (SMAF) (Andrews et al., 2004) and it is based on a three-step process that includes indicator selection, indicator interpretation, and integration into a final index. In northern Italy, several field trials have been set up to assess multiple ES provision from bioenergy crops cultivated on marginal conditions and from contrasting vegetable cropping systems. These studies revealed how the use of a comprehensive soil health assessment framework can help: (1) to identify the best soil management practices that deliver multiple ES and (2) to support resource-efficient production. Beyond academic research, the integration of multiple indicators of soil health within the assessment of agroecosystems sustainability is essential if we want to promote ecological intensification of food and bioenergy production
Carbon sequestration potential in perennial bioenergy crops: the importance of organic matter inputs and its physical protection
Get PDFTo date, only few studies have compared the soil organic carbon (SOC) sequestration potential between perennial
woody and herbaceous crops. The main objective of this study was to assess the effect of perennial woody
(poplar, black locust, willow) and herbaceous (giant reed, miscanthus, switchgrass) crops on SOC stock and its
stabilization level after 6 years from plantation on an arable field. Seven SOC fractions related to different soil
stabilization mechanisms were isolated by a combination of physical and chemical fractionation methods: unprotected
(cPOM and fPOM), physically protected (iPOM), physically and chemically protected (HC-ls + c), chemically
protected (HC-ds + c), and biochemically protected (NHC-ds + c and NHC-ls + c). The continuous C
input to the soil and the minimal soil disturbance increased SOC stocks in the top 10 cm of soil, but not in deeper
soil layers (10–30; 30–60; and 60–100 cm). In the top soil layer, greater SOC accumulation rates were
observed under woody species (105 g m
2 yr-1) than under herbaceous ones (71 g m
2 yr-1) presumably due to
a higher C input from leaf-litter. The conversion from an arable maize monoculture to perennial bioenergy crops
increased the organic C associated to the most labile organic matter (POM) fractions, which accounted for 38%
of the total SOC stock across bioenergy crops, while no significant increments were observed in more recalcitrant
(silt- and clay-sized) fractions, highlighting that the POM fractions were the most prone to land-use change. The
iPOM fraction increased under all perennial bioenergy species compared to the arable field. In addition, the
iPOM was higher under woody crops than under herbaceous ones because of the additional C inputs from leaflitter
that occurred in the former. Conversion from arable cropping systems to perennial bioenergy crops can
effectively increase the SOC stock and enlarge the SOC fraction that is physically protected within soil microaggregates
Measurement of total and extractable enzyme activity from soil and decomposing litter
No full textThe total and extractable activities of the enzymes β-glucosidase (bgluc), cellobiosidase (cell), xilanase (xil), chitinase (chit), leucine aminopepditase (leu) and acid phosphomonoesterase (acP) were determined in soil and decomposing litter of miscanthus (Miscanthus x giganteus L.) and black locust (Robinia pseudoacacia L.). The objective was to quantify the enzyme-specific extractability of a desorption-based fluorometric enzyme assay and whether the extractability is affected by soil and litter type. Soil and litter samples were extracted in 2mL eppendorf tubes with glass/ceramic beads and lysozyme solution. Soil suspensions were incubated in a stirring device and aliquotes of the supernatant were dosed in 384-well microplates after centrifugation to determine total activity. The extractable activity was measured on the supernatant taken from incubated suspension. Extractability of soil enzymes (as % of the total activity) was on average as follows: bgluc (3%), cell (11 %), xil (4%), chit (8%), leu (44%) and acP (13%). A significant effect of SOC and FBC/MBC on acP and leu extractability was observed. Extractability of litter enzymes, instead, was on average as follows: bgluc (25%), cell (10 %), xil (19%), chit (16%), leu (31%) and acP (28%). A significantly higher extractability for chit and leu was observed in miscanthus litter (C/N: 71, Lignin/N: 32) compared to black locust litter (C/N: 17, Lignin/N: 6). We also observed that extractability in both litter types increase significantly in bgluc (+405%), xil (+242%), cell (+217%) and acP (+454%) during the late stage of decomposition. This method enabled the quantification of total and extractable activities of several soil/litter hydrolytic enzymes
Genotype × Environment Interactions of Industrial Hemp Cultivars Highlight Diverse Responses to Environmental Factors
Get PDFStarting with the 2014 Farm Bill, hemp (Cannabis sativa L.) is being re-introduced as an industrial crop in the United States. Since the crop has been absent for over 70 yr, little is known regarding the genetic mechanisms controlling economically relevant traits. Particularly, with federal legality of the crop hinging on a stringent tetrahydrocannabinol (THC) content of 0.3% or less, it is necessary to assess variance in this trait due to environmental effects and genotype × environment interactions (GEI) to avoid running afoul of federal law. Understanding how physical and biochemical traits respond to the environment also plays a strong role in selecting and developing appropriate cultivars for production in diverse growing regions. In 2016 we performed cultivar trials in multiple environments in Colorado to assess performance characteristics of a diverse set of germplasm from breeding programs across Europe and Asia. From these data, we were able to identify traits nearly entirely controlled by genetic factors, like days to maturity and THC and cannabidiol (CBD) production. We also identified traits strongly influenced by the environment and GEI, like grain yield, plant height, and water use. Individual cultivars also exhibited widely varying degrees of sensitivity to the environment. This underscores the importance of continued work to characterize genetic control of hemp traits to expedite breeding of cultivars that are well-adapted to target growing region
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