Soil organic carbon significantly increases when perennial biomass plantations are reverted back to annual arable crops

Funding: This research was supported by funding from the Rural Developing Program (measure 16.01) of the Emilia Romagna region that financed the “FarmCO2Sink” EIP-AGRI operational group (grant number 5015651). Acknowledgments: The authors thank Mike Martin for his support in the modification of the ECOSSE source code.Peer reviewedPublisher PD

Transdisciplinary top-down review of hemp fibre composites: from an advanced product design to crop variety selection

Given the vast amount of available research in the area of natural fibre composites, a significant step forward in the development of next-generation plant fibre-based products would be to devise a framework for rational design. The authors use a top-down approach, starting with an example final product to define the product specifications for high-performance hemp fibre-reinforced composites. Thereafter, all process steps are critically analysed: from textile preform and reinforcement yarn production, to fibre extraction and the agricultural process chain, to the microbiology of field retting, to cultivation and selection of crop variety. The aim of the analysis is to determine how far the current state of knowledge and process technologies are in order to use hemp fibres in high-performance composites. Based on this critical evaluation of the state-of-the-art, it can be stated that hemp will be found in high-performance composites in the short-to-medium term. There is, however, a need for performance optimisation especially through the selection of crop variety, best practices in retting, and effective fibre extraction methods to obtain more consistent fibre qualities suitable for reinforcement spinning and composite preform manufacturing processes

Study of solutions to optimize the extraction of hemp fibers for composite materials

Fibres from hemp stems can be extracted through different mechanical processes following dew or water retting etc. Extraction processes generally have a significant impact on mechanical and morphological properties of the fibres. In this study, hemp fibres are extracted following three different ways. In the first route hemp fibres are extracted from FUTURA 75 variety stems by performing scutching, hackling and microwave degumming. A second batch of fibres of the same variety was extracted by scutching and hackling after an initial microwave degumming treatment. In the third route, the same variety of hemp fibres are extracted from dew retted stems grown at Piacenza (Italy). Finally, the mechanical properties of single fibres as well as the fineness of technical fibres of all types of extracted fibres are evaluated and compared and the interest of the microwave degumming for hemp stem is evaluated

An automated whole-canopy multi chamber system for live monitoring water use efficiency in sorghum

Plant growth and productivity are strongly affected by limited water availability in drought prone environments. The current climate change scenario, characterized by long periods without precipitations followed by short but intense rainfall, force plants to implement different strategies to cope with drought stress. Understanding how plants use water during these period of limited water availability, and which are the molecular mechanisms at the basis, is of primary importance to identify and select the best adapted genotypes to a certain environment. Two sorghum genotypes, previously characterized as drought tolerant and drought sensitive, were subjected to progressive drought stress through a dry-down experiment protocol. An automated multi-chamber system was used in this experiment to determine in vivo whole-canopy water use efficiency. This system allows to record five measurements per hour of the whole-canopy transpiration and photosynthetic rate and to calculate instantaneous water use efficiency. In this experiment the transpiration and net photosynthetic rate were coupled with gene expression daily dynamics of drought related genes. The drought tolerant genotype showed an increased expression in all the genes tested, whilst the drought sensitive genotype had an opposite trend for some of them. In particular, the daily expression trend of two genes, one coding for a carbonic anhydrase and the other for a mitochondrial K+ channel, was highly correlated with the daily trend of transpiration rate, indicating that these genes are highly involved in the control of stomatal aperture in both genotypes. The daily trend of a putative ERECTA-like gene expression could be overlapped to the daily trend of water use efficiency of the two sorghum genotypes subjected to drought stress, enabling to promote this gene as marker for screening selection for water use efficiency trait in sorghum

Economics of GHG emissions mitigation via biogas production from Sorghum, maize and dairy farm manure digestion in the Po valley

AbstractThe Greenhouse gas (GHG) emissions and economic feasibility of electricity production from the anaerobic digestion of different substrates are studied in this paper. Three realistic substrate options for the climatic and soil conditions of a modelled farm in the Po Valley in Italy are analysed: manure from a dairy farm, Sorghum and maize.A detailed cost analysis is performed with field data provided by farmers and suppliers and literature sources. The capital costs (CAPEX) and the operational costs (OPEX), disaggregated by their components, are presented. Investment payback time is then calculated for the different substrates and technologies, while taking into account the Italian government feed-in tariff scheme for biogas plants implemented in 2013.In the specific conditions assumed, electricity production via anaerobic digestion of manure and co-digestion of manure with at most 30% Sorghum (no till) provide both GHG savings (in comparison to the Italian electricity mix) and profit for economic operators.The anaerobic digestion of silage maize or Sorghum alone, instead, provides no (or very limited) GHG savings, and, with the current feed-in tariffs, generates economic losses.Both economic and environmental performance are improved by the following practices: cultivating Sorghum instead of maize; implementing no till agriculture; and installing gas-tight tanks for digestate storage. A tool allowing a customised calculation of the economic performances of biogas plants is provided

Hemp (Cannabis sativa L.) leaf photosynthesis in relation to nitrogen content and temperature: implications for hemp as a bio-economically sustainable crop

Hemp (Cannabis sativa L.) may be a suitable crop for the bio-economy as it requires low inputs while producing a high and valuable biomass yield. With the aim of understanding the physiological basis of hemp's high resource-use efficiency and yield potential, photosynthesis was analysed on leaves exposed to a range of nitrogen and temperature levels. Light-saturated net photosynthesis rate (Amax) increased with an increase in leaf nitrogen up to 31.2\uc2 \uc2\ub1\uc2 1.9\uc2 \uce\ubcmol m\ue2\u88\u922 s\ue2\u88\u921 at 25\uc2 \uc2\ub0C. The Amax initially increased with an increase in leaf temperature (TL), levelled off at 25\ue2\u80\u9335\uc2 \uc2\ub0C and decreased when TL became higher than 35\uc2 \uc2\ub0C. Based on a C3 leaf photosynthesis model, we estimated mesophyll conductance (gm), efficiency of converting incident irradiance into linear electron transport under limiting light (\uce\uba2LL), linear electron transport capacity (Jmax), Rubisco carboxylation capacity (Vcmax), triose phosphate utilization capacity (Tp) and day respiration (Rd), using data obtained from gas exchange and chlorophyll fluorescence measurements at different leaf positions and various levels of incident irradiance, CO2 and O2. The effects of leaf nitrogen and temperature on photosynthesis parameters were consistent at different leaf positions and among different growth environments except for \uce\uba2LL, which was higher for plants grown in the glasshouse than for those grown outdoors. Model analysis showed that compared with cotton and kenaf, hemp has higher photosynthetic capacity when leaf nitrogen is <2.0\uc2 g N m\ue2\u88\u922. The high photosynthetic capacity measured in this study, especially at low nitrogen level, provides additional evidence that hemp can be grown as a sustainable bioenergy crop over a wide range of climatic and agronomic conditions