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Rock phosphate constitutes a natural phosphorus (P) source for organic farming systems, but with a limiting direct agricultural use due to its poor inherent reactivity. Thus, this work studies the effect of the co-composting of rock phosphate with green wastes and elemental sulfur on phosphorus availability. Six composts were prepared combining different green wastes and rock phosphate in three different proportions (0%, 0.27% and 0.54% P fresh mass basis) and elemental sulfur in two proportions (0% and 0.5% S fresh mass basis). During composting, the temperature of the mixtures was monitored, as were physico-chemical and chemical parameters, especially those related to phosphorus. The co-composting of green wastes with rock phosphate improved phosphorus mobilization and also constituted a viable method to manage green wastes, obtaining P-enriched compost for organic farming systems. Sulfur addition favored the composting process and also phosphorus solubilization, especially in the mixture with the lowest proportion of rock phosphate. [ABSTRACT FROM AUTHOR]

The growth of the agri-food industry has resulted in a strong increase in its sludge generation. This type of waste is often produced in high amounts, concentrated in certain areas, and shows characteristics similar to those of municipal sewage sludge (except for the absence of heavy metals). Composting has been widely studied as a viable alternative for the treatment and recycling of municipal sewage sludge, but little information is currently available concerning the composting of agri-food sludge. Thus, the aim of this work was to increase our knowledge of how the vegetable-derived sludge produced by the agri-food sector can be managed using different co-composting strategies. The work was concerned mainly with the characteristics of the bulking agents used (type and particle size) and their effects on the development of the process and on the potential added value of the composts obtained. For this, four composting piles were prepared using agri-food sludge and two bulking agents (vine shoot prunings and pepper plant pruning waste) at two particle sizes (<1 cm and <3 cm). The evolution of the process and the final properties of the composts obtained were studied using classical analytical methods together with advanced instrumental methods (thermal analysis and excitation–emission matrix (EEM) fluorescence spectroscopy). In addition, their physical characteristics and potential suppression of phytopathogens ( Fusarium oxysporum f. sp. melonis ) were determined. The results showed differences according to the type and size of bulking agent, the mixtures with vine shoot prunings having a higher biodegradability, which was confirmed by thermogravimetry and EEM fluorescence spectroscopy. Melon plants grown in a mixture which included compost produced using vine pruning waste had a greater shoot weight than those grown on peat alone, while the mixture including compost derived from pepper pruning waste gave a shoot weight similar to that of peat-grown plants. Furthermore, the composts elaborated using vine shoot prunings had added value with respect to their use as growing media components for seedling production of melon, due to their suppression of F. oxysporum f. sp. melonis . Therefore, this study has shown that the nature of the bulking agent used is of major importance not only for the development of the composting process, but also for the final properties and potential added value of the end-products obtained. [ABSTRACT FROM AUTHOR]

Terpenoid, fat-soluble antioxidant and fatty acid (FA) composition of pasture as well as those of milk and cheese from a commercial sheep flock managed under extensive mountain grazing in the east region of the Cantabrian mountain (Northern Spain) was investigated. The grazing period lasted for 2 months and ewes were at late lactation stage. Plants, feces, bulk milk and cheese samples were collected on two sampling dates. The abundance of the dominating botanical families in the mountain pasture prevailed in the sheep diet of the commercial flock. Major terpenoids and tocols in the pasture appeared as major ones in milk and cheese, whereas C18 unsaturated FAs in milk and cheese were derived from the intake of C18 polyunsaturated FAs which were prevalent in the pasture. No carotene was detected in the dairy samples but retinol (free or esterified), derived from the intake of β -carotene present in pasture plants, was found in milk and cheese. [ABSTRACT FROM AUTHOR]

Composting is a feasible, environmentally-friendly management tool for the treatment of animal manures based on nutrient recovery. However, the liquid character of the pig slurry, with low dry matter, requires previous solid–liquid separation and the mixture of the solid fraction with an adequate bulking agent in the correct ratio. This work studies the influence of the bulking agent proportion on the composting of the solid fraction of pig slurry, focussing on the development of the process and on the greenhouse gas emissions. For this, two mixtures of the solid fraction of pig slurry and cotton gin waste, in different proportions, were prepared (4:3 and 3:4 solid fraction of pig slurry:cotton gin waste, v:v) and composted by the Rutgers static pile system in a pilot plant (2000 kg each pile). The temperature profiles of the composting piles were similar, but the pile with the greater proportion of bulking agent showed higher temperatures and a longer thermophilic phase, with greater aeration demand. The specific heat capacity of cotton is lower than those of other bulking agents used frequently for animal manure composting, which means that this material requires less energy from microbial activity for its temperature to increase. However, the easily degradable organic matter present in the pig slurry explained the faster organic matter mineralisation occurred in the pile with the higher proportion of solid fraction of pig slurry; in pile with higher proportion of bulking agent, the mineralisation process was slower due to the lignocellulosic character of the cotton gin waste. The organic matter mineralisation was closely related to the gaseous emissions (mainly as carbon dioxide): significant methane emissions were detected when the highest organic matter degradation occurred in the pile with the greater proportion of solid fraction of pig slurry, together with the highest nitrogen oxide emissions – indicating the existence of anaerobic pockets within the composting mass. So, it can be concluded that the thermal properties of the bulking agent were responsible for the temperature development and aeration demand, while the gaseous emissions were related to the organic matter degradation process. The composts produced were stable, with a good degree of maturation; the compost with the higher proportion of solid fraction of pig slurry had greater organic matter humification and higher nutrient concentrations. [ABSTRACT FROM AUTHOR]

Abstract: Digestate, the by-product of the anaerobic digestion, can present characteristics which would limit its recycling by direct use in agricultural soils. Composting can be a feasible treatment to stabilise digestate and thus, to improve its properties for using as a soil conditioner or substrate. The aim of this work was to study the viability of composting for the recycling of digestates after solid–liquid separation and the effect of the bulking agent used in the characteristics of the end-products obtained. For this, five piles were elaborated by mixing the solid fraction of a pig slurry digestate (SD) with different bulking agents (wheat straw (WS), vine shoot prunings (VP), exhausted grape marc (EGM) and pepper plant prunings (PP)). Also, one of these piles was watered with the liquid fraction of the pig slurry digestate (LD). Throughout the composting process, the temperature of the mixtures was monitored and physico-chemical, chemical, physical properties and maturity degree were determined. Also, factorial analysis (FA) was used for interpreting the data set of compost characteristics. The composts obtained showed a suitable degree of stability and maturity and suitable physical properties for their potential use as growing media. Also, the type of bulking agent strongly influenced the development of composting and the final properties of the composts, showing the mixtures with WS and VP the most suitable characteristics. [Copyright &y& Elsevier]

Abstract: This work focuses on the viability of composting for the recycling of digestates, to obtain added-value organic materials with potential use in agriculture. Mixtures made from the solid fraction of a digestate (obtained from the anaerobic co-digestion of cattle slurry and silage), with or without vine shoot prunings as bulking agent, were composted by the Rutgers composting system. During composting, the temperature of the composting piles was monitored, as were physico-chemical, chemical, and maturity parameters. Potential added-value properties of the final composts, such as their physical characteristics and in vitro suppression of Fusarium oxysporum f. sp. melonis, were determined. The bulking agent had a positive effect, reducing the electrical conductivity and the N losses during composting and also diluting the heavy metal contents of the end-products. The composts obtained showed adequate degrees of stability and maturity, suitable physical properties for use as growing media, and suppression of F. oxysporum f. sp. melonis. [Copyright &y& Elsevier]

Abstract: The effects on different physico-chemical, chemical and biological soil properties of the incorporation of different organic materials into a calcareous vineyard soil were studied in an experiment during three growing seasons. The organic materials used were sheep manure and four composts derived from the treatment of winery and distillery wastes. A multivariate technique, factor analysis (FA), was also used for interpreting the data obtained from the samplings carried out throughout the three vine growing seasons. The application of the organic materials induced an increase in the activity of the soil microorganisms and in the soil macro and micronutrient contents, as well as a slow release of inorganic N. Through FA of the soil properties studied, three factors that explained 74.7% of the variability were established and the effects of the treatments after the whole experimental period were assessed. [Copyright &y& Elsevier]

Abstract: The application of organic materials to replenish soil organic matter and improve soil structure and fertility has become a common agronomic practice. This research deals with the effects of soil amendment with winery and distillery waste composts on organic carbon (C) mineralisation in two arable soils. A sandy-loam and clay-loam soil were treated and incubated with a number organic materials obtained from the co-composting of different proportions of grape stalk, grape marc, exhausted grape marc and vinasse, with sewage sludge or animal manure. Moreover, the effect of compost stability on C mineralisation dynamics was studied by applying organic materials from different stages of the composting process. The results obtained showed that the addition of exogenous organic matter stimulated microbial growth, enhanced soil respiration and increased water-extractable C contents in both soils, particularly in the days immediately following amendment. The initial composition of the different organic materials used, especially for the mature samples, and the texture of the receiving soil did not influence significantly the C mineralisation final values, with around 11–20% of the added organic C being mineralised over the first 140days. However, the contribution of organic amendment to the labile organic C pool, maximum rates of soil respiration, as well as the extent of initial disturbance of the soil microbiota were all found to be related to the degree of organic matter stability. Moreover, irrespective of the type and stability of the organic amendment, the mineralogical composition of the receiving soil was found to significantly influence its resilience in such systems. [ABSTRACT FROM AUTHOR]

Abstract: Physico-chemical, chemical and microbiological parameters were studied in a set of fifteen different composts elaborated with agroindustrial wastes using two different composting systems (turning and static pile composting). To carry out the chemometric evaluation, multivariate statistical analysis techniques, such as hierarchical cluster analysis (HCA) and factorial analysis (FA) were used. Composts obtained showed suitable physico-chemical and chemical properties for their use as organic amendment and a good maturity degree. HCA allowed to classify the organic materials mainly in four groups: cluster A, cluster B, cluster C and unclustered composts; also, this statistical tool showed the lack of influence of the composting system in the final characteristics of these composts. On the other hand, through FA, it was possible to identify the principal variables associated to the composting of agroindustrial wastes in four factors that explained 72.3% of the variability. [Copyright &y& Elsevier]

Abstract: Physico-chemical, chemical and biological parameters were studied throughout the composting process of four winery and distillery composts and the data set of compost characteristics was analysed using multivariate techniques: factorial analysis (FA) and linear discriminant analysis (LDA), in order to classify the different parameters studied and thus, to establish those that better describe the composting process of this type of wastes. Through factorial analysis (FA) of the parameters studied throughout the composting process, four components that explained 85.6% of the variability were established. The parameters associated to compost maturity, agronomic character, water-soluble fraction and ammonia and temperature increment were grouped in the components F1, F2, F3 and F4, respectively, which can reduce the number of determinations needed to ascertain the maturity and quality of the composts. In addition, the linear discriminant analysis on the factorial components makes possible to classify the four composts with a percentage of success around 95%. [Copyright &y& Elsevier]

The aim of this study was to monitor some microbial indicators and pathogen contents (sulphite reducers clostridia, total enterobacteriaceae, total coliforms, faecal coliforms (Escherichia coli), enterococci, Staphylococcus aureus and Salmonella spp.) throughout the co-composting of wastes from the winery and distillery industry with other organic residues, as well as the effect of the composting system used. Seven different piles using mixtures of winery–distillery wastes with other organic materials were prepared. P1 and P2 were made using grape stalk (GS), grape marc (GM), exhausted grape marc (EGM) and sewage sludge (SS), whereas in P3 and P4 were also used exhausted grape marc with cow manure (CW) and poultry manure (PM), respectively, using the Rutgers system. Additionally, P2 was watered with vinasse (V). The rest of piles (P5, P6 and P7) were prepared with grape marc, exhausted grape marc, cow manure and poultry manure, using the turning system. The effectiveness of the composting process to reduce the pathogen content was higher in the static aerated piles than in those elaborated with the turning. The relatively high temperatures (50–60°C) reached in some of the piles produced a notable decrease in some microbial groups, such as total and faecal coliforms (E. coli), but the characteristics of the raw materials used notably influenced the pathogen contents of the end-product. [Copyright &y& Elsevier]

The aim of this work was to study the viability of recycling the solid wastes generated by the winery and distillery industry by means of co-composting with animal manures, as well as to evaluate the quality of the composts obtained. Two piles, using exhausted grape marc and cattle manure or poultry manure, respectively (at ratios, on a fresh weight basis, of 70:30), were composted by the Rutgers static pile composting system. Throughout the composting process, a number of parameters were monitored, such as pH, electrical conductivity, organic matter, water-soluble carbon, water-soluble polyphenols, different forms of nitrogen (organic nitrogen, ammonium and nitrate) and humification indices (humification ratio, humification index, percentage of humic acid-like C, polymerisation ratio and cation exchange capacity), as well as the germination index. Organic matter losses followed first-order kinetics equation in both piles, the highest organic matter mineralisation rate being observed with exhausted grape marc and cow manure. On the other hand, the mixture with the lowest C/N ratio, using exhausted grape marc and poultry manure, showed the highest initial ammonium contents, probably due to the higher and more labile N content of poultry manure. The increase in the cation exchange capacity revealed the organic matter humification during composting. In contrast, other humification parameters, such as the humification ratio and the humification index, did not show the expected evolution and, thus, could not be used to assess compost maturity. Composting produced a degradation of the phytotoxic compounds, such as polyphenols, to give composts without a phytotoxic character. Therefore, composting can be considered as an efficient treatment to recycle this type of wastes, due to composts presented a stable and humified organic matter and without phytotoxic effects, which makes them suitable for their agronomic use. [Copyright &y& Elsevier]

The winery and distillery industry produces a great quantity of residues, whose management and disposal are environmental problems due to their seasonal character and some polluting characteristics. The main solid by-products and residues generated are grape stalk, grape pomace or marc, wine lee, exhausted grape marc and winery sludge. In this study, 87 samples of winery and distillery residues were collected from different Spanish wineries and distilleries. Electrical conductivity, pH, total organic matter, organic carbon, polyphenols and contents of plant nutrients and heavy metals were determined. The purpose of this research was to study the composition of these wastes and to find relationships in order to use easily analysable parameters to estimate their composition. In general, the winery and distillery residues showed low pH (mean values ranged from 3.8 to 6.8) and electrical conductivity values (1.62–6.15dSm−1) and high organic matter (669–920gkg−1) and macronutrient contents, especially in K (11.9–72.8gkg−1). However, a notable polyphenol concentration (1.2–19.0gkg−1) and low micronutrient and heavy metal contents were also observed, some of these properties being incompatible with agricultural requirements. Therefore, conditioning treatments are necessary prior to possible use of these wastes. In all wastes, significant correlations were found between easily determined parameters, such as pH, electrical conductivity and total organic matter, and most of the parameters studied. The regression models obtained are also discussed. [Copyright &y& Elsevier]

Abstract: The aim of this work was to study the influence of the organic wastes derived from the winery and distillery industry (grape stalk (GS), grape marc (GM), wine lees (WL) and exhausted grape marc (EG)) and the soil type (clayey-loam (S1), loam (S2) and sandy textured (S3)) on different soil characteristics, especially the carbon and nitrogen mineralisation. The evolution of C mineralisation fitted a first-order kinetic for all amended soils. An initial increase was observed in the specific respiration (qCO2) at the beginning of the experiment. However, afterwards, the evolution in the qCO2 was to tend towards the values of the control soil due to the pattern of the soil to recover its initial equilibrium status. The addition of these materials in the soils produced a slight increase of the inorganic nitrogen content, except in the case of GS and EG in most of the studied soils. The use of GS as amendment produced an inhibition in the N mineralisation in the three types of soils studied. Organic matter mineralisation was probably influenced by soil type, the sandy soil favouring more the N and C mineralisation processes than the clayey-loam and loam soils. [Copyright &y& Elsevier]

Cheeses were manufactured with 2 levels of lamb rennet paste or bovine rennet, at two times of the year, to study the effect of artisanally prepared lamb rennet paste (at high and low levels) on the concentrations of proteolysis products (nitrogen fractions, casein degradation and free amino acids). Cheeses made with the lamb rennet paste presented a significantly different evolution of the αs1-I-casein fraction during ripening, as measured by urea polyacrylamide gel electrophoresis. The time of the year affected the concentrations of 39% of the individual free amino acids, as determined by reversed-phase high-pressure liquid chromatography. The relationship between some biochemical parameters (gross composition, degrees of lipolysis (Lamb rennet paste in ovine cheese manufacture. Lipolysis and flavour. International Dairy Journal (2003) in press) and proteolysis) and the sensory characteristics of the cheese (Virto et al., 2003) were studied by a principal component analysis. The effect of the technological parameters “type of rennet” and “time of the year” on these analytical variables and sensory characteristics of the cheese was described by three principal components which explained 80.8% of the total variance. The factor “rennet paste” included concentrations of short chain free fatty acids, sensory descriptors related to strong odours and flavours, an unidentified peptide A1, and αs1-I-caseins. The effect of the ‘time of the year’ was described by two other factors: the “secondary proteolysis” factor, which included the concentrations of free amino acids and could be related to the different endogenous microflora of the raw milk, and the “seasonal milk composition” factor, which included the fat content and the plasmin activity of the milk. [Copyright &y& Elsevier]

• A washing pre-treatment was applied to livestock derived substrates. • The washing pre-treatment did not affected negatively substrate physical properties. • The growing media with washed composts showed positive effects on seedlings. The search for alternative materials for peat substitution in soilless systems has led to an increasing use of compost as ingredient of growing media. These materials may have similar characteristics to peat for their potential use as substitutes of this non-renewable material. However, the high salinity is one of the most usual limiting factors in compost for its use in growing media. This work evaluates the effect of the use of a washing pre-treatment to improve the quality of livestock waste-derived composts as peat substitutes in substrates for pepper (Capsicum annuum L.) seedling production. For this, different growing media were prepared using as ingredients five composts from livestock manures and anaerobic digestates (M1, M2, M3, D1 and D2), with or without a washing pre-treatment. Each respective material was mixed with peat in the proportions 25 %, 50 % and 75 % (volume:volume), using as control treatment pure (100 %) peat. The main physico-chemical, chemical and physical characteristics of the composts before and after washing and those of the growing media were studied, as well as germination and biomass production of the seedlings. The use of a washing pre-treatment was effective in the reduction of compost salinity, without implying a negative effect on the physical properties and nutrient content of the growing media, which were adequate for being used in seedling production, as reflected in the beneficial effects on the germination and growth of pepper seedlings. [ABSTRACT FROM AUTHOR]

Abstract In the Mediterranean countries, there is an increasing production of date palm wastes (Phoenix dactylifera L.), not only due to the raising production of date palm fruits, but also derived from the maintenance of urban and peri-urban green areas, especially in those affected by red palm weevil (Rhynchophorus ferrugineus). The management of this increasing volume of green wastes usually concludes with a controlled disposal that implies an important loss of resources, in terms of organic matter, nutrients and energy. In addition, the rise of wastewater generation and the incentive of the wastewater treatment processes have derived in an increase of the amount of the sludge produced, which makes difficult its management. This work studies the feasibility of co-composting palm wastes with sludge from the urban and agri-food sectors as alternative treatment to manage these organic waste streams and to obtain added-value compost. For this, four mixtures (P1, P2, P3 and P4) were prepared using as main component palm leave waste (PL) mixed with different types of sludge. In the piles P1, P2 and P3, sewage sludge (SS) was used as co-composting agent, while agri-food sludge (AS) was used in P4. Throughout composting, the thermal profile of the composting piles was assessed, as were physical, chemical, physico-chemical and maturity parameters. In addition, the changes in water-soluble organic matter were assessed using chemical analytical methods and the excitation–emission matrix (EEM) fluorescence spectroscopy. The results obtained showed the viability of the co-composting process to obtain end-products with adequate maturity degree and physical characteristics for their potential use as substrates, except for the salt contents that can limit their use in some agricultural sectors. Graphical abstract Image Highlights • Palm waste can be managed by co-composting with sewage and/or agri-food sludge. • The composts obtained showed a suitable physical and chemical quality. • The use of date palm waste increased the salt contents in the final composts. [ABSTRACT FROM AUTHOR]

Solid waste management is a huge challenge in developing countries mainly due to factors such as population increase, poverty and the lack of proper investment by the respective governments. Composting, if it is properly carried out, can constitute a viable method for organic waste management in these countries, due to its low operational cost and the income generation, with low environmental impact. Thus, this paper studies composting as treatment method for the sustainable management and recycling of the municipal solid wastes generated in the Chimborazo Region (Ecuador), and the use of some of the composts obtained as growing media for seedling production. For this, six piles were elaborated using municipal solid wastes: Piles 1, 2 and 3 were prepared using municipal solid wastes from the Riobamba landfill and Piles 4, 5 and 6 were elaborated using source-separated market waste and urban pruning wastes. After composting, composts C3, C4 and C5 (from Piles 3, 4 and 5, respectively) were used as substrates components, mixed with peat in different percentages (0, 25, 50 and 75%, volume/volume) for seedling production of tomato, courgette and pepper. The composts obtained showed adequate physico-chemical and chemical properties, and a suitable degree of stability and maturity, with absence of phytotoxicity. Regarding their use as growing media, the substrates with 25% (volume/volume) of the compost C3, C4 or C5 had the best properties for their use as substrate components, only C3 reducing the seed germination in the courgette crop. In addition, at an economic level, the alternative of peat substitution at 25% with compost can suppose a reduction of 23% in the cost of the substrate. In the most conservative scenario, this reduction can be of 21%, also with an increase of 2.9% in the business contribution margin. Therefore, composting can be a suitable method not only for the management and recycling of these waste streams, but also for adding value to them, as components of growing media in seedling production. [ABSTRACT FROM AUTHOR]

The purpose of the experiment was to study the effects of the use of three different types of winery–distillery composts as substrate components for thyme ( Thymus vulgaris) cultivation on the yield and composition of the essential oils present in this herb. A major component of the composts was exhausted grape marc combined with different quantities of one of the following co-composting wastes: citrus juice waste (for compost C1), tomato soup waste (for compost C2) or cattle manure (for compost C3). The substrates were prepared by mixing traditional peat–perlite mixture (PP) with increasing proportions of each respective compost (0%, 25%, and 50% by volume) and the physical and physico-chemical properties of the substrates were analyzed. The best results for the cultivation of thyme were obtained with the growing media prepared using composts derived from exhausted grape marc mixed with citrus juice waste (C1) or cattle manure (C3). Essential oils were extracted by hydrodistillation and analyzed using GC–MS and GC–FID. Forty-six volatile compounds were tentatively identified, with thymol, p -cymene, carvacrol, linalool and 1,8-cineole (eucalyptol) being the major compounds. The total concentration of volatiles in the control samples (29.6 g kg −1 ) was significantly increased in treatment B (to 34.6 g kg −1 ), consisting of compost C1 at the proportion 50% by volume, and treatment E (to 37.6 g kg −1 ), made from compost C3 at the proportion 25% by volume, showing that the characteristics of the composts used as components of the growing media strongly affected the production of essential oils in the thyme plants. [ABSTRACT FROM AUTHOR]

Abstract: The effects of two different spent mushroom substrates on soil physico-chemical, chemical and biological properties were studied in a plot experiment with a horticultural crop (Lactuca sativa L. var. linus). Two organic treatments were applied: spent mushroom substrate from Agaricus bisporus crop (T1) and a mixture of spent mushroom substrate from A. bisporus crop and spent mushroom substrate from Pleurotus crop (50% (v/v)) (T2), both treatments providing 100kgha−1 of nitrogen. The unamended soil was used as control treatment (C). pH, electrical conductivity (EC), oxidisable organic C (oxidisable OC), available P, organic N, NH4 +-N, NO3 −-N, N loss, soil respiration and enzymatic activities (catalase, urease and phosphatase) were measured during 126days after spent mushroom substrate addition to the soil. The organic amendment, particularly T1 treatment, increased the oxidisable OC, organic N and available P content of the soil. The application of spent mushroom substrates did not produce great changes on soil physico-chemical properties (pH and EC) with respect to the control soil. Organic N content in the amended soils increased at the beginning of the experiment, coinciding with the period in which N losses were positive (N gain). In all soils, NH4 +-N concentration increased throughout the first two weeks of experiment and then these parameters decreased to the end of the experiment. However, the evolution of the NO3 −-N content tended to decrease in all soils throughout the experiment, in the amended soil observing an initial nitrification inhibition. Finally, the addition of spent mushroom substrates increased soil respiration rate and phosphatase activity, not producing great differences in catalase and urease activities with the incorporation of these wastes into soil. [Copyright &y& Elsevier]

Abstract: The intensification in livestock production has increased the need of efficient treatments of waste streams especially to preserve as much as possible, the nutrients into the soil-plant system. Composting is a cheap, efficient and sustainable treatment for solid wastes that is always included in any manure treatment scenario. In this paper, an overview about the environmental and safety challenges of composting of manures is made considering the compost quality requirements established by the main demanding sectors. Co-composting and additive strategies are presented as feasible options for the improvement of compost quality. For quality evaluation of manure compost, the use of both classical and innovative instrumental techniques could increase our knowledge about added properties in compost, especially those related to organic matter stability. [Copyright &y& Elsevier]

In a preliminary study with commercial ewe''s milk cheeses, there were statistically significant differences in the sensory evaluation scores and the amounts of short-chain (C4–C10) free fatty acids (FFAs) between cheeses made with lamb rennet paste or bovine rennet. Experimental ewe''s milk cheeses were manufactured with 2 levels of artisanally produced lamb rennet paste and 2 levels of bovine rennet in 50 L vats, with a manufacturing replicate done within 1 week. Total coagulating activity was 2500 RU for cheeses manufactured with a high amount of rennet or 1000 RU for cheeses manufactured with a low amount of rennet. The two batches of lamb rennet pastes used had 4.0 (early Spring) and 6.5 U g−1 lipase (late Spring), whereas no lipase activity was detected in bovine rennets. The total concentration of FFAs in cheeses manufactured with lamb rennet paste was significantly higher than in cheeses manufactured with bovine rennet, regardless of ripening time and time of the year. Lipolysis in the former cheeses increased with the total units of lipolytic activity added. The increase in lipolysis in cheeses made with lamb rennet was primarily due to higher amounts of short-chain fatty acids (C4–C10). Butyric acid was the main FFA in cheeses made with lamb rennet paste, representing 34.5 μmol 100 μmol−1 (low level of rennet) and 44.2 μmol 100 μmol−1 (high level of rennet) of the total FFAs, whereas it represented only 17 μmol 100 μmol−1 of the total FFAs in all cheeses made with bovine rennet. The concentration of individual FFAs of chain length

Among the largest producers of waste, the paper industry stands out due to its impact on human health and ecological balance. However, these residues may also contribute to a more environmental friendly brick industry, since the incorporation of fluxing agents may improve the firing process and the induced porosity reduces thermal conductivity of fired bricks. Therefore, this study aims to assess the feasibility of replacing clay with solid paper residue (PPR) from 2.5 to 17.5% in order to reduce resources depletion and improve brick performance. The original clay was characterized as a non-calcareous red clay with high contents of kaolinite. Several samples were made by extrusion and fired at 900 °C in accordance with industrial procedures. The addition of PPR led to increase shrinkage from 5 to 10% due to the effect of fluxing oxides which reduced pores volume and enlarged pores size. In addition, the impervious fraction was slightly reduced while the apparent porosity certainly increased (i.e. approx. 17%) due to the macroscopic pores developed by PPR combustion. This porosity produces lighter bricks (i.e. density decays from 1.76 to 1.39 g dm−3) with lower thermal conductivity (i.e. from 5.53 to 0.41 W m−1 K−1) but also reduces compressive strength (i.e. from 11 to 3 MPa) and increases water absorption (i.e. up to 24%). Nevertheless, toxicity is below the regulatory limits in all cases and fired bricks are easily adaptable to industrial procedures. Unlabelled Image • Pulp and paper industry generates large amounts of solid waste. • Fluxing oxides improve structural skeleton of non-calcareous kaolinitic clays. • Industrial procedures have been followed for samples forming. • Technological properties and toxicity have been assessed. • Depending on the purpose of brick, replacement up to 7.5% is possible. [ABSTRACT FROM AUTHOR]

• Optimization of the bio-oxidative phase for 35 days is feasible. • The obtained compost presented high quality properties for agricultural use. • The duration of the bio-oxidative phase mainly affects the compost maturity. • Spectroscopic analyzes validate the quality of the organic composts. The aim of this study was to evaluate the effect of considering different composting times on compost quality before the end of the bio-oxidative phase and after the maturation and storage phases. This study may provide useful information to optimize the composting process and increase the economic feasibility of the technology and its adoption without decreasing the quality of the end-product. In this study, three composts were prepared using chicken meat processing wastes mixed with urban tree trimmings, serving as a bulking agent, to evaluate the effect of reducing the durations of the bio-oxidative phase and the maturity stage on the different physico-chemical properties. Specifically, we evaluate water-soluble organic matter transformations by using excitation–emission matrix (EEM) fluorescence spectroscopy. The obtained results have shown that a composting time of 35 days combined with eight turnings was efficient for achieving the standard process control parameters for agro-industrial waste composting in the studied conditions and allowed for the production of stable and mature compost that is suitable for agricultural use. [ABSTRACT FROM AUTHOR]

This work evaluates several co-composting scenarios based on the use of Arundo donax biomass (AD) as bulking agent for the co-composting of sewage sludge (MS) and agri-food sludge (AS), to manage these organic wastes and to produce balanced organic fertilizers by optimizing the process. For this, six piles were prepared in commercial composting conditions, using AD in a range of 40%–80% (on a dry weight basis). Physico-chemical and chemical parameters and the thermal behaviour were evaluated during the process, as were the physical and chemical parameters of the final composts. The proportion of AD in the mixtures has a significant effect on the development of the thermophilic stage of composting, showing the piles with higher proportion of AD a quicker organic matter degradation. In addition, the evolution of the thermal indices R1 and R2 was different depending on the origin of the sludge used, indicating an increase in the relative concentration of more recalcitrant materials in the piles prepared with AS. The estimation of the global warming potential showed that the use of higher proportion of AD in the composting mixture may be a strategy to mitigate the emission of greenhouse gases during the composting process. Moreover, the end-products obtained had an additional marketable value, with a balanced nutrient content and a good degree of maturity, which indicates the viability of the composting process as a method for the stabilization of these organic wastes. [ABSTRACT FROM AUTHOR]

Although the use of composts derived from anaerobic digestates as soil amendments is likely to increase in the future, there is little information concerning the fate of their C and N compounds after their incorporation into soil. This work assesses C and N concentrations and the associated changes in δ15N and δ13C during the composting processes of cattle and pig slurry anaerobic digestates. In addition, the compost effect on C and N fractions and plant uptake were studied during a six-month pot experiment with rosemary plants. The results did not show δ13C and δ15N isotopic discrimination during composting, indicating a previous stabilization of cattle manure and pig slurry during the anaerobic digestion. This fact was also confirmed by the low C losses during the composting processes (1.2-fold and 1.05-fold for the composting piles with cattle and pig slurry anaerobic digestates, respectively). After soil addition, the composts augmented N values (from 0.41 g kg−1 to around 0.56 g kg−1 in low dose and 0.68 g kg−1 in high dose compost amended soils) and δ15N soil values (increases in the range of 50%–156%), but showed only slight differences in C and δ13C values compared to unfertilised control and inorganic fertilized soils. Moreover, the rosemary leaves of the plants grown on the compost amended soils presented higher N and δ15N abundance than control and inorganic fertilized plants. We conclude that δ15N abundance of anaerobic digestate composts is useful to discern its N uptake and could thus be a useful tool to detect whether organic or mineral fertiliser types were used for agricultural production. • δ13C and δ15N isotopic discrimination was not observed during composting. • Composts increased δ15N soil values compared to control and mineral fertilized soils. • δ15N abundance of anaerobic digestate compost can be useful to discern its N uptake. [ABSTRACT FROM AUTHOR]

The increasing salinisation in the agricultural environments of coastal Mediterranean areas results in complex scenarios for the biomass production, which have to combine both high production and photosynthetic efficiency to overcome the high osmotic potentials at the root level. Thus, the recovery of the productive capacity in marginal and degraded areas derives, in some cases, in the production of biomass for non-food uses. In this experiment, Arundo donax L. (AD) was used as an energy crop to check its tolerance and behaviour in saline environments. For this, crop conditions were established in a soil with an increasing presence of salinity. In addition, the implication of this crop on its capacity for C fixation in soils, especially related to its rhizome, and the possible use of its biomass for bioenergy production can constitute additional benefits of this practice. Therefore, the C pools in the soil-AD systems were assessed and quantified using near infrared reflectance spectroscopy (NIRS). The experiment was developed during three consecutive years. Several parameters were studied: fresh and dry yields of aerial biomass and rhizomes, C and N contents, different bioagronomic parameters (no. of plants m −2 , average height/stem, no. of knots/stem, average diameter and distance to basal knot). Also, the potential for salt extraction of AD was evaluated using a salt balance, as well as the potential for atmospheric C fixation. Arundo donax showed a high tolerance to saline conditions and a significant adaptation to salt accumulation in soil. In addition, AD systems can constitute efficient C fixation systems due to the significant C sink that supposes its rhizome, with an overall annual fixation of around 13 kg CO 2 m −2 . NIRS may constitute a viable technique for the quick estimation of C contents, especially in the aerial parts and rhizomes of Arundo donax . [ABSTRACT FROM AUTHOR]

Agriculture in the Mediterranean basin is currently contributing to greenhouse gas emissions (GHG) and in the future is expected to be strongly affected by climate change. Increasing soil organic carbon (SOC) via soil organic matter (SOM) improvement is widely regarded as a way to both mitigate and adapt to climate change. Using as a case study the Mediterranean coastal area in Spain, which is regarded as one of the most intensively managed areas in Europe for orchards and horticultural cropping, we analyzed the potential for climate change mitigation of introducing different practices that are expected to increase SOC. We selected both as a single measure and in combination, cover cropping and application to the soil of the available underutilized exogenous organic matter (EOM), treated (e.g. composted or digested) or non-treated. These practices were compared against a baseline scenario that intended to reflect the current practices in the area (e.g. all livestock manure produced in the area is applied to the agricultural soil). We carried out a modelling exercise at the regional scale using the agricultural activity data and current climatic conditions as inputs. Modelling runs were performed coupling a widely used dynamic model of SOC turnover (RothC) with a model to simulate the GHG emissions from EOM processing or storage prior to soil application (SIMS WASTE ). Results indicate that the most promising practice, considered as a single measure and with respect to the baseline, was introducing cover crops in woody cropping systems. This practice resulted in an increase of 0.44 Mg C ha −1 yr −1 during the first 20 years (range 0.41–0.52 Mg C ha −1 yr −1 ) and led to a total SOC accumulation of about 30 Tg C after 100 years. Amendment of all agricultural land with available underutilized EOM resulted in an increase of up to 0.09 Mg C ha −1 yr −1 (range 0.07–0.16 Mg C ha −1 yr −1 ) as a single measure (urban waste) and 0.13 Mg C ha −1 yr −1 (range 0.11–0.21 Mg C ha −1 yr −1 ) as a combined measure (urban waste and composted agroindustry by-products), leading to a total SOC accumulation of about 7 Tg C (urban waste) and 10 Tg C (urban waste and composted agroindustry by-products) after 100 years. Manure anaerobic digestion or composting as a single measure did not result in significant SOC changes but, if GHG emissions and savings from manure storage and processing management stages are considered, they could help to reduce about 4.3 (anaerobic digestion) or 1.1 Tg CO 2 eq yr −1 (composting) in the study area, which represents a significant amount compared with total agricultural emissions in Spain. [ABSTRACT FROM AUTHOR]

The aim of this work was to study the changes during 15 days in the monoterpene emission rates of the Mediterranean shrub rosemary ( Rosmarinus officinalis L.), in response to increasing drought stress and fertilisation using two different composts derived from livestock anaerobic digestates (cattle and pig slurry). Drought stress considerably reduced photosynthetic rates, stomatal conductance and isoprenoid emissions and also induced a change in blend composition. In the drought stressed rosemary plants, a positive relationship of non-oxygenated monoterpene emissions and a negative relationship of oxygenated monoterpene with photosynthesis were observed, indicating a different control mechanism over the emissions of the two types of isoprenoids. The emission of non-oxygenated monoterpenes seemed to depend more on photosynthesis and “de novo” synthesis, whereas emission of oxygenate monoterpenes was more dependent on volatilisation from storage, mainly driven by cumulative temperatures. In the short term, the addition of composted organic materials to the soil did not induce a significant effect on isoprenoid emission rates in the rosemary plants. However, the effect of the interaction between fertilisation and seasonality on isoprenoid emission rates was influenced by the amendment origin. Also, we emphasized changes in potential isoprenoid emission factors throughout the experiment, probably indicating changes in the leaf developmental stage. [ABSTRACT FROM AUTHOR]

The agri-food industry is at the centre of the circular economy, since the co-composting of its residual flows allows their management and adds value producing fertilisers. In this work, six composting piles were prepared combining agri-food sludge (AS), different fresh vegetable wastes (pepper waste (P), tomato waste (T), and leek waste (L), and, as bulking agents, vine shoot pruning (VS), garlic stalks (GS) and avocado leaves (AL)). Classical physico-chemical and chemical determinations and advanced instrumental methods (excitation-emission fluorescence (EEM) and gravimetric (TG, DTG and DTA) techniques) were used and compared to assess organic matter evolution and evaluate the quality of the composts obtained. The thermal profiles of the composting processes were viable to show the stabilization of the agri-food sludge with the different materials tested in the mixtures, reaching adequate levels of stabilization of organic matter. Preferential degradation of peptides and proteins was observed by fluorescence. This seemed to induce a limitation in the biodegradation of the remaining organic matter, indicating that these biomolecules are key in composting dynamics, acting as limiting components during the process. The results from thermogravimetric analysis indicated the degradation of labile compounds (e.g., carbohydrates and proteins), the most recalcitrant material becoming predominant at the maturity stage of the composting process. The rise in the thermogravimetric parameter R2 was associated with the increase in the concentration of more refracting compounds, which need more energy for their decomposition. • Fluorescence and thermal analyses allowed to study biomolecules effect in composting. • Proteins and humic/fulvic substances can limit organic matter dynamic in composting. • Proteins and peptides constitute a key/limiting component of the composting process. [ABSTRACT FROM AUTHOR]

Abstract: The positive effect of part-time grazing with three different amounts of indoor-supplied concentrate on milk production and quality was studied in an experimental flock of latxa sheep in mid-lactation. The group that received the highest amount of concentrate (group 3) ingested the least amount of grass during the 4h the animals were on the pasture. Milk production increased by 30% (p ⩽0.05) in the three groups that were allowed to graze as compared with the milk produced by the control group (group 0; always fed indoors). No change in the milk gross composition among the four experimental groups was observed. The milk from group 1 (which received the lowest amount of concentrate) had the highest concentration (p ⩽0.05) of unsaturated fatty acids (FA), both total and polyunsaturated (PUFA), and the highest percent (56%) of non-atherogenic saturated FA (p ⩽0.05) as compared to 49% in the control group. Consequently, the atherogenicity index of the milk from group 1 was the lowest (p ⩽0.05) of all groups. In addition, the concentration of CLA isomer c9t11 in this milk was 50μg/g fat, but only 15μg/g fat in the control group and around 33μg/g fat in groups 2 and 3. Changes in milk triglyceride composition were also observed between control group and grazing animals. The Trolox equivalent antioxidant capacity (TEAC) value of milks from groups 1 and 2 was higher than those of milks from groups 0 or 3. Curd firmness to compression was lowest (p ⩽0.05) in milk from group 1. These results clearly indicate that part-time grazing is a viable alternative to intensive indoor sheep milk production which allows the use of locally available resources and improves the nutritional quality of the milk. [Copyright &y& Elsevier]

Abstract: Composting is an environmentally friendly alternative for the recycling of organic wastes and its use is increasing in recent years. An exhaustive monitoring of the composting process and of the final compost characteristics is necessary to certify that the values of compost characteristics are within the limits established by the legislation in order to obtain a safe and marketable product. The analysis of these parameters on each composting batch in the commercial composting plant is time-consuming and expensive. So, their estimation in the composting facilities based on the use of near infrared reflectance spectroscopy (NIRS) could be an interesting approach in order to monitor compost quality. In this study, more than 300 samples from 20 different composting procedures were used to calibrate and validate the NIRS estimation of compost properties (pH, electrical conductivity (EC), total organic matter (TOM), total organic carbon (TOC), total nitrogen (TN) and C/N ratio, macronutrient contents (N, P, K) and potentially pollutant element concentrations (Fe, Cu, Mn and Zn)). The composts used were elaborated using different organic wastes from agroindustrial activities (GS: grape stalk; EGM: exhausted grape marc; GM: grape marc; V: vinasse; CJW: citrus juice waste; Alpeorujo: olive-oil waste; AS: almond skin; EP: exhausted peat; TSW: tomato soup waste; SMS: spent mushroom substrate) co-composted with manures (CM: cattle manure; PM: poultry manure) or urban wastes (SS: sewage sludge) The estimation results showed that the NIRS technique needs to be fitted to each element and property, using specific spectrum transformations, in order to achieve an acceptable accuracy in the prediction. However, excellent prediction results were obtained for TOM and TOC, successful calibrations for pH, EC, Fe and Mn, and moderately successful estimations for TN, C/N ratio, P, K, Cu and Zn. [Copyright &y& Elsevier]

Abstract: The content and chemical forms of P in compost are essential variables for its proper management with an agricultural purpose, especially considering the increasing P over-fertilization in agrosystems. In this study, the estimation of P content and dynamics in different composting scenarios was developed using near infrared reflectance spectroscopy (NIRS) coupled with a statistical tool for calibration, a penalized signal regression. Samples were analyzed on total P and partitioned using NaOH-solution 31P NMR spectroscopy quantifying pyrophosphate, orthophosphate, orthophosphate diesters, phospholipids, and orthophosphate monoesters pools. According to the results obtained, total P content (r 2 =0.99 and root mean square error of cross-validation=0.53) and P forms can be estimated during composting using NIRS, as well as in the mature product, orthophosphate and orthophosphate monoesters being the most abundant P forms throughout the experiment. Penalized signal regression allows detecting the significant wavenumbers in each composting period, and also with the different P pools in the composting pile depending on time. [Copyright &y& Elsevier]

This research work was conducted in order to investigate the possibility of using spent mushroom substrate (SMS) in the production of horticultural seedlings replacing part of the peat in the growing media. Three vegetable species with different salt sensitivities, the less sensitive being tomato (Lycopersicon esculentum var. Muchamiel), the moderately salt-sensitive being courgette (Cucurbita pepo L. var. Afrodite F1) and the most salt-sensitive being pepper (Capsicum annum L. var. Lamuyo F1) were grown in 12 media containing SMS of two types of mushroom (Agaricus bisporus (SMS-AB) and Pleurotus ostreatus (SMS-PO)) or a mixture of both 50% (v/v) (SMS-50), as well as peat in various ratios. The proportions of each residue in the mixtures elaborated with peat were 25%, 50%, 75% and 100% v/v residue. A substrate of 100% peat was used as control. The experiment was arranged in a completely-randomised design with two replicates per treatment under greenhouse conditions. Prior to sowing, some physical, physico-chemical and chemical properties of the growing media were determined and seed germination and fresh weight of seedling were also measured. In most of the cases, the addition of SMS to the growing media produced an increase in the pH values, salt contents, macro and micronutrient concentrations and a decrease in the water holding capacity contents in comparison to peat, whereas great differences were found in the air capacity values between SMS-based substrates and peat. Up to 75% SMS can be used in mixtures with peat for seed germination of the plant species studied. Regarding the most suitable SMS-based substrates for plant growth, any substrate could be used for tomato seedling production. However, all SMS-AB-based substrates and the media containing low dose of SMS-PO and SMS-50 were adequate for growth of courgette and pepper. [Copyright &y& Elsevier]

• Bricks made by bottom ashes, cellulose fibers and clay have been successfully made and tested. • Optimum blends are made of 70% of clay, 25% of bottom ashes and 5% of cellulose fibers. • The so made bricks comply mechanical requirements and are 20% lighter. • Lower thermal conductivity and equal specific heat capacity is achieved. • Toxicity analysis abides by standards in force. The paper and pulp industry (PPI) is permanently searching for new ways of managing its residues due to the increasing pressure of new environmental concerns and policies adopted worldwide. In addition, the manufacturing of construction materials such as fired clay bricks (FCBs) is also facing the transformation of its traditional market, which is asking for new materials with a lower environmental footprint but equal or even better technological properties. In considering the large mass flows related to both the PPI and FCB industries, several researchers have pointed out the feasibility of replacing clay by residues produced by PPI. However, these approaches have always considered the replacement of a single residue rather than the addition of several new ones. Conversely, by using both residues at once, the overall FCB performance is improved and the feasibility of this circular economy approach is eased. For instance, the addition of woody fibres increases thermal resistance but reduces mechanical strength. Conversely, the addition of ashes produced by PPI improved the mechanical strength by reducing the thermal resistance due to the increasing content of fluxing agents which improve the fired clay matrix structure. For this reason, this paper explores the technological properties achieved by replacing clay with both ashes and fibres provided by PPI in an integrated approach. By following industrial procedures, the so made fired clay bricks (with 20% of ash and 5% of fibres) meet the standard and show approx. 20% less thermal conductivity, with the same thermal capacity and a density reduction of more than 15%. [ABSTRACT FROM AUTHOR]

The aim of the present paper is to assess the maturity degree reached by different samples of several mixtures from winery and distillery residues composted using the Rutgers composting system, by means of excitation–emission matrix (EEM) fluorescence spectroscopy. The composts were sampled once a week for about 200d. EEM spectra indicate the presence of different fluorophores. The fluorescence intensities of these peaks show trends related to the maturity of the composting samples selected. The “contour density” of EEM maps is strongly modified through time. We have used the quantitative method of fluorescence regional integration (FRI). The EEMs were delineated into five excitation–emission regions. The degree of compost maturity could be correlated with the percentage of the volumetric integration under the EEM within each region. Further refinement of these techniques should provide a relatively rapid method for assessing the suitability of the compost to soil application. [Copyright &y& Elsevier]

Abstract: The possibility of using thermal analysis for a quick characterization of chemical changes was tested in the organic matter from composting materials. Differential thermal analysis (DTA), thermogravimetry (TG) and the first derivative of the TG (DTG) were calculated in oxidizing conditions on compost samples obtained from three composting piles. The composting piles were made by mixing winery and distillery residues with sewage sludge (pile 1), with cow manure (pile 2) and hen droppings (pile 3). The temperature values in the pile 1 showed a different evolution during the thermophilic stage of the composting process in relation to the piles 2 and 3. The thermophilic stage for pile 1 was 17 days, meanwhile for the piles 2 and 3 were around 80 and 110 days, respectively, and probably pile 1 was not well composted. The curves of ion current of CO2 have been recorded in order to shed light on changes occurring in organic matter during composting. Particularly DTG curves allowed us to distinguish between well (piles 2 and 3) and poor (pile 1) stabilized organic matter. The energy released was calculated for each sample by integrating the DTA curves and these results are agreed with the previous hypothesis. Information deriving from weight losses, registered by the TG and DTG curves, enables to follow the evolution state of the organic matter and therefore changes in its stability. These data could determine the final point of the composting process of winery and distillery residues and then reduce the time for compost harvest. [Copyright &y& Elsevier]

Abstract: Water deficit and soil degradation have become some of the major problems for crop production in semi-arid regions, as it is the South East of Spain. As a matter of fact, considerable productivity loss and risk of erosion have to be taken into account in these areas, especially those with an horticultural use (Davis, 1989). Utilization of sewage sludge in agriculture. Agricultural Progress 64, 72–80]. Horticultural soils are highly vulnerable and prone to erosion, as vegetables are generally fast-growing species under intensive exploitation regimes. High-rate chemical inputs contribute to horticultural soil degradation and have a dramatic effect on soil microbial population and nutrient balance whilst, at the same time, have a counter-effect on price competitiveness of the vegetables to be commercialized. In this paper we monitored variations in physical, chemical and biological properties of a cauliflower plot where four increasing quantities of compost were applied. We carried out a three-stage sampling schedule in order to check the effect of compost applications doses. We conclude that a 2kg compost/m2 application had a positive effect on physical and biological properties of the soil and provides a supply of nutrients to grow cauliflowers on its surface under intensive exploitation regimes without loss in biomass yield. [Copyright &y& Elsevier]

• Two in situ bioremediation strategies were used for OMW sediment decontamination. • Composting and composting-vermicomposting reduced OMW sediment toxicity. • Vermicomposting was more effective in the reduction of the phenolic compounds. During the last two decades, the method most widely used to manage olive mill wastewater (OMW) derived from olive oil production has been its disposal in evaporation ponds. Long-term storage of OMW leads to the accumulation of toxic sediments (OMWS) rich in recalcitrant compounds with phytotoxic and antimicrobial properties, which limit their use for agronomic purpose. The aim of this study was to compare the effect of two in situ bioremediation strategies (composting and a combination of composting followed by vermicomposting) to remove the potential toxicity of the sediments derived from long-term stored OMW. The results obtained showed that the composting method assisted with the earthworms enhanced the depletion of phenolic compounds and OMWS ecotoxicity more than composting, especially during the maturation stage. Moreover, vermicomposting was more effective in the reduction of the OMWS salinity. However, a pre-composting process to the OMWS is necessary prior to vermicomposting to provide the suitable conditions for earthworms survival and activity. Furthermore, the final compost showed a phytostimulating effect. Therefore, these in situ bioremediation strategies can be considered potential tools for decontamination and recovery of long-term stored OMWS in evaporation ponds, which currently poses an unsolved environmental problem. [ABSTRACT FROM AUTHOR]

• Paper and pulp residues are used for manufacturing adobe bricks. • Compressive strength is increased up to 190% for 12.5% of replacement. • Thermal conductivity is reduced approx. 30% for 12.5% of replacement. • The water resistance complies with standards up to 12.5% of replacement. • Toxicity values meets the standards up to 20% of replacement ratio. Soil-based building material has been used since ancient times but lately it has been mainly considered for restoration purposes of traditional architecture instead of an eco-friendly construction material for new buildings. However, the promotion of a more sustainable architecture has recently led to look towards adobe or rammed earth, among others. Because of the high impact of concrete and the fired clay brick industry, mainly due to the use of clinker and the firing process, respectively, adobe may highly reduce the ecological footprint of conventional construction and building materials. In addition, the use of fibers for adobe reinforcement has been also highlighted as a key factor for improving adobe performance. Obviously, when residues successfully replace such fibers the ecological footprint may be reduced even more. Thus, this research focuses on the assessment of adobe reinforced with paper and pulp industry residues (PPR) with the aim of demonstrating the feasibility of this construction material. Several series have been made by varying the replacement percentage up to 20% and technological properties and toxicity have been assessed. It is concluded that compressive strength may be improved up to 190% while thermal conductivity is reduced approx. 30% for 12.5% of PPR replacement. Besides, adobe meets standards related to water resistance and toxicity values. [ABSTRACT FROM AUTHOR]

Agricultural production of leafy vegetables in Mediterranean countries aims to achieve high yields without elevated nitrate contents in the edible parts. This implies an adjusted nutrient management, especially of nitrogen (N), in irrigated horticultural systems under semiarid conditions. These horticultural systems are highly relevant in SE Spain from an economic perspective. However, the management of N fertilizer, generally applied in large amounts (150–250 kg N ha−1 in a split application), could trigger losses of reactive N to the environment. The use of novel fertilizers may fulfill the nitrogen requirements of the crop, but should also help to decrease the environmental impacts of production, thus achieving carbon-neutral horticultural systems through (e.g.) enhancement of carbon (C) stocks and greenhouse gases (GHG) emission abatement. In this experiment, eight different fertilizing scenarios at a normalized N application rate of 150 kg N ha−1 were assessed in terms of crop yields, nutrients uptake, C stocking capacity, and yield-scaled GHG emissions. Inorganic NPK fertilizers, digestates, biosolids, composts, and vermicomposts were included among this set of fertilizers. Our results show that organic-based stabilized materials, especially composts, lowered the NO 3 − concentration in spinach leaves, in comparison to organic raw materials and synthetic fertilizers. They also produced yields similar to those of slow-release synthetic fertilizers, but with a significant increase in soil organic C 61 days after application. In general, N 2 O emissions were positively affected by the treatments. Nevertheless, direct N 2 O emissions were generally low (the highest emission factor, 0.13, being for the biosolid treatment) due to the combined mitigating effect of both the edapho-climatic conditions and the management practices. In general, cumulative CO 2 emissions were high in all organic scenarios compared to the control treatment (299 kg C-CO 2 ha−1), the highest values being observed in the treatment with biosolid (589 kg C-CO 2 ha−1), probably due to differences in the labile organic C contents. In conclusion, some of the organic-based treatments showed multiple positive effects: on crop quality (i.e. leaf N content), crop yields, and GHG mitigation potential. Based on our results, the use of these materials represents an optimized N fertilizer strategy to help achieve a circular economy, by closing nutrient loops and decreasing the environmental impacts of horticultural production systems in semiarid regions of southern Europe. Unlabelled Image • An intensive, commercial spinach crop under Mediterranean conditions was studied. • Yield, leaf nitrate, C sequestration and greenhouse gas emissions were considered. • Nitrate accumulation in spinach leaves was related to novel forms of fertilizer. • New emission factors (EFs) for direct and yield-scaled N 2 O emissions are reported. • The EFs for Mediterranean conditions were significantly lower than the IPCC standards. [ABSTRACT FROM AUTHOR]

The objective of this work was to study the possibilities to manage and recycle dog faeces (DF) using biological processes, using two approaches: composting (C) and anaerobic digestion (AD). Thus, different experiments have been carried out: i) two laboratory/pilot scale experiments (self-heating and composting tests) and one, on a commercial scale; ii) two AD experiments. In both approaches, municipal waste such as the organic fraction of municipal solid waste (OMSW) and urban pruning waste (GW) were used as co-substrates. The results obtained regarding the optimization of the composting process indicated that the best strategy was the use of a 1:2 ratio of DF, a 1:4 ratio of OMSW, and a 1:4 ratio of GW, according to the thermal parameters studied (temperature and cumulative quadratic exothermic index (EXI2)), and the quality of the compost obtained. A potentially limiting factor of the process was the high salinity of the DF waste. In addition, AD experiments were performed on DF, OMSW, and GW wastes in controlled anaerobic systems at a laboratory scale. In these experiments, the biogas production obtained was 229 mL biogas/g total solids for the DF residue, 248 mL biogas/g total solids for GW, and 263 mL biogas/g total solids for OMSW. The co-digestion yields a clear improvement in the efficiency of the process against the use of a single residue, increasing the production of biogas by up to 27% with respect to that of the DF waste alone during the first 25 days of AD. The results obtained with these procedures have shown the possibilities to add value to this waste in an urban context where the circular economy represents an increasingly favourable scenario, including the generation of fertilisers and/or energy at a local scale, provided that the collection of dog faeces is optimized. • Composting and anaerobic digestion are feasible treatments for dog faeces management. • Salinity can be a limiting aspect in the composting of dog faeces. • The biogas yield seems to be improved with the co-digestion of dog faeces. [ABSTRACT FROM AUTHOR]