• Energy Research
• Closed Access close
• Open Source close
• 2. Zero hunger close
• CA close
• ES close

SummaryWater accounting is an unresolved issue in metabolism studies. Through epistemological analysis, we show that the problem resides in the conceptualization of social metabolism. Social metabolism has its origins in the analysis of societal energetics, which has led to an exclusive focus on society and a representation based on linear throughputs at a single scale. Whereas fossil energy resources constitute a mere stock flow for society, water constitutes a set of both funds and flows essential for the maintenance of the internal organization and stability of society and ecosystems. This means that societies and ecosystems need water for different reasons. Consequently, the analysis of water requires the simultaneous adoption of multiple narratives and scales. The development of hydrology toward a socio‐eco‐hydrology (SE‐hydrology) deals with this multidimensionality, but lacks a conceptualization of the coupled human‐water system useful to integrate the assessment of water processes at different rates and scales. We propose a conceptual framework, based on the multiscale integrated analysis of societal and ecosystem metabolism approach, that combines the perspectives of SE‐hydrology and social metabolism. This framework describes society and the embedding ecosystem as two distinct levels of the same hierarchical system (i.e., the socioecological system), expressing two distinct, but tightly interconnected, metabolic patterns (societal and ecosystem) at different spatiotemporal scales. Using food grain production in Punjab as an example, we show that this framework can accommodate the multiple interpretations of social metabolism found in different scientific fields.

Italy is the most important European country in terms of paddy rice production. North Italian districts such as Vercelli, Pavia, Novara, and Milano are known as some of the world's most advanced rice cultivation sites. In 2013 Italian rice cultivation represented about 50% of all European rice production by area, and paddy fields extended for over 216,000 ha. Cultivation of rice involves different agricultural activities which have environmental impacts mainly due to fossil fuels and agrochemical requirements as well as the methane emission associated with the fermentation of organic material in the flooded rice fields. In order to assess the environmental consequences of rice production in the District of Vercelli, the cultivation practices most frequently carried out were inventoried and evaluated. The general approach of this study was not only to gather the inventory data for rice production and quantify their environmental impacts, but also to identify the key environmental factors where special attention must be paid. Life Cycle Assessment methodology was applied in this study from a cradle-to-farm gate perspective. The environmental profile was analyzed in terms of seven different impact categories: climate change, ozone depletion, human toxicity, terrestrial acidification, freshwater eutrophication, marine eutrophication, and fossil depletion. Regarding straw management, two different scenarios (burial into the soil of the straw versus harvesting) were compared. The analysis showed that the environmental impact was mainly due to field emissions, the fuel consumption needed for the mechanization of field operations, and the drying of the paddy rice. The comparison between the two scenarios highlighted that the collection of the straw improves the environmental performance of rice production except that for freshwater eutrophication. To improve the environmental performance of rice production, solutions to save fossil fuel and reduce the emissions from fertilizers (leaching, volatilization) as well as methane emissions should be implemented.

Abstract Several strategies based on a two steps organosolv pretreatment followed by enzymatic hydrolysis of sugarcane bagasse (SCB) were evaluated with the objective of selecting operational conditions suitable to promote an efficient and low cost production of ethanol. Initially, the influence of six variables used for the organosolv pretreatment was studied. The variables included the time of the first organosolv pretreatment step, the use of 45% ethanol as pulping solution, solid-to-liquid ratio of the ethanol solution used during the first pretreatment step, time of second organosolv pretreatment, concentration of ethanol and concentration of NaOH solution used in the second pretreatment step. Further assays of enzymatic hydrolysis were carried out to promote additional reduction in the costs of the process and improve the results of cellulose conversion to glucose. Eliminating the milling step of the pretreated SCB, using a commercial tensoactive (composed of esters and several surfactants), and recycling 50% of the slurry obtained during the second step of organosolv pretreatment as reaction medium proved to be feasible for use during the enzymatic hydrolysis. Fermentation of the glucose medium produced under the selected pretreatment conditions to ethanol by Saccharomyces cerevisiae occurred with 81% efficiency and a cost of 102.88 $/hL of ethanol.

Intraspecific variability in nitrogen use has not been comprehensively assessed in a natural poplar species. Here, a nitrogen isotope mass balance approach was used to assess variability in nitrogen uptake, assimilation and allocation traits in 25 genotypes from five climatically dispersed provenances of Populus balsamifera L. grown hydroponically with either nitrate or ammonium. Balsam poplar was able to grow well with either ammonium or nitrate as the sole nitrogen source. Variation within provenances exceeded significant provenance level variation. Interestingly, genotypes with rapid growth on nitrate achieved similar growth with ammonium. In most cases, the root:shoot ratio was greater in plants grown with ammonium. However, there were genotypes where root:shoot ratio was lower for some genotypes grown with ammonium compared to nitrate. Tissue nitrogen concentration was greater in the leaves and stems but not the roots for plants grown with ammonium compared to nitrate. There was extensive genotypic variation in organ-level nitrogen isotope composition. Root nitrogen isotope discrimination was greater under nitrate than ammonium, but leaf nitrogen isotope discrimination was not significantly different between plants on different sources. This can indicate variation in partitioning of nitrogen assimilation, efflux/influx (E/I) and root or leaf assimilation rates. The proportion of nitrogen assimilated in roots was lower under nitrate than ammonium. E/I was lower for nitrate than ammonium. With the exception of E/I, genotype-level variations in nitrogen-use traits for nitrate were correlated with the same traits when grown with ammonium. Using the nitrogen isotope mass balance model, a high degree of genotypic variation in nitrogen use traits was identified at both the provenance and, more extensively, the genotypic level.

SummaryBioethanol production in North America has led to the production of considerable quantities of different co‐products. Variation in nutrient profiles as well as nutrient availability among these co‐products may lead to the formulation of imbalanced diets that may adversely affect animal performance. This study aimed to compare three types of dried distiller’s grains with solubles [100% wheat DDGS (WDDGS); DDGS blend1 (BDDGS1, corn to wheat ratio 30:70); DDGS blend2 (BDDGS2, corn to wheat ratio 50:50)] and their different batches within DDGS type with regard to: (i) protein and carbohydrate sub‐fractions based on Cornell Net Carbohydrate and Protein System (CNCPS); (ii) calculated energy values; and (iii) rumen degradation of dry matter (DDM), organic matter (DOM), crude protein (DCP), neutral detergent fibre (DNDF) and starch (Dstarch) at 36 and 72 h of ruminal incubations. Wheat DDGS had a lower intermediately (PB2, 136.4 vs. 187.4 g/kg DM) and a higher slowly degradable true protein (PB3, 142.2 vs.105.3 g/kg DM) than BDDGS1, but similar to those of BDDGS2. Sugar (CA4) was higher, whereas starch (PB1) and digestible fibre (PB3) were lower in WDDGS than in BDDGS1 and BDDGS2. All carbohydrate sub‐fractions determined differed significantly between the two batches of BDDGS2. The BDDGS2 had the highest calculated energy values (TDN, DE3×, ME3×, NEL3×, NEm and NEg) among the three DDGS types. The energy values were slightly different between the batches of the three DDGS types. At all incubation times, wheat DDGS had a significantly higher (p < 0.05) DDM, DOM, DCP and DNDF than both DDGS blends. Differences were observed between different batches within DDGS types with regard to in situ rumen degradation of DM, OM, CP, NDF and starch. In conclusion, differences were observed in protein and carbohydrate sub‐fractions and in situ ruminal degradation of DM, OM, CP, NDF and starch among the three DDGS types and different batches within DDGS type. This indicates that the nutrients supplied to ruminants may not only differ among different types of DDGS but it may also differ among different batches within DDGS type.

Abstract Biomass is a key element within the Europe's Bioeconomy Strategy. This paper aims at contributing to a better knowledge of the evolution and current state of biomass trade in Spain by adopting a raw material equivalent approach. Instead of measuring trade flows in actual physical quantities, this approach expresses international trade flows in terms of the raw material needed to produce the traded products. The results obtained show that while raw material input of biomass increased by 3560 thousand tonnes over the period 2008–2016, raw material consumption decreased by 15,086 thousand tonnes. This is explained by the different pace of growth registered by raw material equivalent of exports and of imports: while raw material equivalent of exports rose from 49,485 thousand tonnes in 2008 to 68,131 thousand tonnes in 2016 recording a double digit growth of 38%, the increase in raw material equivalent of imports was considerably lower: from 64,560 thousand tonnes to 66,106 thousand tonnes, an increase of 2%. By categories, biomass from agriculture was the main driver of overall trade of biomass. Two groupings deserve special mention: fodder crops, which accounted for one quarter of raw material equivalent of exports, and cereals, which represented almost one third of raw material equivalent of imports in 2016.

Abstract The effects of extractives, particle size, and crop species on the contents of structural carbohydrates, lignins, and micro-components in Canada Prairie Spring (CPS) wheat, durum wheat, barley, oat, and triticale straw, as well as flax shives, were determined. Extraction for 24 h in water followed by 7 h in ethyl alcohol (EtOH) yielded 20.2% extractives in triticale straw. Acid insoluble lignin decreased from 17.6% in native triticale straw to 13.6% in 24 h water + 7 h EtOH extracted triticale straw. The sample particle size influenced the values of glucan, xylan, acid insoluble lignin, ash, and extractives. Glucan, xylan, and acid insoluble lignin levels increased with increasing particle size. Protein, ash, and extractive levels decreased with increasing particle size. For flax shives, glucan, xylan, and acid insoluble lignin levels increased with increasing particle size from 19.1% to 33.2%, from 6.7% to 18.8%, and from 17.4% to 25.7%, respectively. The protein, ash, and extractive levels in flax shives decreased with increasing particle size from 6.5% to 1.9%, from 27.7% to 0.9%, and from 15.0% to 3.8%, respectively. Total glycans, lignin and extractive levels for the various straws, from the medium particle sized fraction, were 56.6–63.9, 14.7–19.4, and 6.8–20.2%, respectively. Total glycans, lignin, and extractives levels from the medium particle sized flax shives were 51.8, 25.8, and 6.46%, respectively. The composition of the medium particle size fraction reflected the composition of the corresponding original sample.

AbstractCanola meal, a by‐product of oil pressing, is a rich source of phenolic antioxidants. However, its use in the food and feed sector is still limited by the need for greener, sustainable, and more cost‐effective extraction methods. This study used accelerated solvent extraction (ASE) to enhance the extraction efficiency of the phenolic antioxidants. The high selectivity and short extraction time associated with ASE were ideal for obtaining high yields of these antioxidants. The structure‐based activity of phenolic compounds may be influenced by the high pressure and temperature of the greener ASE process. The present study evaluated the effect of temperature (140, 160, and 180 °C) and pressure (1,500 psi) on the extraction and yield of phenolic compounds from canola meal as well as the solvent type (ethanol and methanol) and concentration (30%, 40%, 60%, and 70% v/v). Antioxidant activity was determined by 2,2‐diphenyl‐1‐picrylhydrazyl, ferric reducing/antioxidant power assay, and ion‐chelating activity. The highest yield of phenolic compounds was obtained with 70% methanol (20.72 ± 1.47 mg SAE/g DM [milligrams of sinapic acid equivalents per gram of dry matter]) and 70% ethanol (24.71 ± 2.77 mg SAE/g DM) at 180 °C temperature. A similar trend was observed for the antioxidant activity of the extracts and their total flavonoid content. The structure‐based antioxidant activity of the extracts examined increased with the increase in the percentage of the extracting solvent (P > 0.05). This study established ASE as an efficient green method for extracting phenolic compounds from canola meal, with potential application for the production of natural bioactive compounds from underutilized agricultural by‐products.Practical ApplicationASE is an efficient eco‐friendly method for extracting phenolic compounds from agricultural by‐products such canola meal. Under the conditions of high pressure and temperature, ASE significantly improved the yields of phenolic compounds, sinapine, sinapic acid, and canolol. Under these conditions, water, as an extractant, was not effective in extracting sianpine. Moreover, it was much less effective than both 70% ethanol and 70% methanol in extracting sinapine or canolol. These phenolic compounds are of great interest as natural antioxidants for enhancing the shelf life of food products. They also represent new sources of neutraceuticals for improving human health.