Evaluation of batch mesophilic anaerobic digestion of raw and trampled llama and dromedary dungs: methane potential and kinetic study

Funding for open access publishing: Universidad Pablo de Olavide/CBUA. This study was funded y the project FEDER UPO-1380782 financed by the regional government of Andalucía, Junta de Andalucía, Consejería de Trasformación Económica, Industria, Conocimiento y Universidades and the project PID2020-114975RB-100/AEI/10.13039/501100011033 financed by the Spanish Ministry of Science and Innovation.This research was carried out with the aim to evaluate the anaerobic digestion (AD) of llama and dromedary dungs (both untreated and trampled) in batch mode at mesophilic temperature (35 °C). The biochemical methane potential (BMP) tests with an inoculum to substrate ratio of 2:1 (as volatile solids (VS)) were carried out. The methane yield from trampled llama dung (333.0 mL CH4 g¿1 VSadded) was considerably higher than for raw llama, raw and trampled dromedary dungs (185.9, 228.4, 222.9 mL CH4 g¿1 VSadded, respectively). Therefore, trampled llama dung was found to be the best substrate for methane production due to its high content of volatile solids as well as its high nitrogen content (2.1%) and more appropriate C/N ratio (23.6) for AD. The experimental data was found to be in accordance with both first-order kinetic and transference function mathematical models, when evaluating the experimental methane production against time. By applying the first-order kinetic model, the hydrolysis rate constants, kh, were found to be 19% and 11% higher for trampled dungs in comparison with the raw dung of dromedary and llama, respectively. In addition, the maximum methane production rate (Rm) derived from the transference function model for trampled llama dung (22.0 mL CH4 g¿1 VS d¿1) was 83.3%, 24.4% and 22.9% higher than those obtained for raw llama manure and for raw and trampled dromedary dungs, respectively.Universidad Pablo de Olavide de Sevilla. Departamento de Sistemas Físicos, Químicos y Naturale

Silvopastoral systems as a tool for territorial sustainability and biodiversity

Rural and livestock population evolution in the inner north of Portugal has demonstrated a great regression with consequences for environment and nature conservation. In this context, and taking into account that pastoral activity has shaped the natural areas of mountain territories since its beginning and that territories are currently part of Natura 2000 network, rethinking the importance of such activity has become vital. The constraints affecting daily tasks performed by shepherds and livestock breeders as well as the installed social segregation are a strong limitation. However, current research developed in the context of nature conservation has demonstrated the importance of the landscape mosaic promoted by grazing in the preservation of priority habitats. In this way, it is urgent to assess the issue of shepherds and livestock breeders’ image in terms of their roles, relationships and concerns, as well as to assess pastoralism socioeconomics in regard to self-consumption, market and rural self-sufficiency. In this perspective, this work presents an analysis of the adaptation of grazing to current times, perceiving its limitations and success potential.This work is supported by European Structural and Investment Funds, FEDER component, through the Operational Competitiveness and Internationalization Programme (COMPETE 2020) [Project No. 006971 (UID/SOC/04011)], and national funds, through FCT, Portuguese Foundation for Science and Technology under project UID/SOC/04011/2013.info:eu-repo/semantics/publishedVersio

Differences in nutrient composition of sea fennel (Crithmum maritimum) grown in different habitats and optimally controlled growing conditions

10 páginas.- 1 figura.- 5 tablas.- referenciasCrithmum maritimum L. is an edible halophyte with large potential in human nutrition field. However, it is unclear whether its nutritional value is maintained throughout the contrasting habitats where it commonly grows (cliffs, sandy and rocky beaches) and the nutritional profile of cultivated plants still remains uncertain. In this work, we provided for the first time a comparison of the nutritional profile of C. maritimum across its different type of habitats in the south of Spain and between wild plants and plant material under optimal growing conditions. The protein, amino acids, lipids, fatty acids, minerals composition and phenolic content of plants were analysed. Plants under field conditions exhibited a nutritionally balanced composition (3.8–6.2 g protein/100 g DW, 4.9–7.5 mg lipids/g WW, 3.9–5.0 g Na/100 g DW), with high phenolic content (30.2–48.0 mg/g DW) regardless of the variability of the contrasting habitats. In contrast, under optimal conditions, C. maritimum showed a greater protein and lipid content (10.2 g/100 g DW and 9.6 mg/g WW, respectively), and lower sodium accumulation (1.2 g/100 g DW), allowing a greater consumption of this halophyte without exceeding the daily intake recommendations. Conversely, phenolics were strongly decreased in these plants (6.1 mg/g DW) likely due to the absence of stress factors. © 2021 Elsevier Inc.This work was financially supported by two grants from the Spanish Ministry of Science, Innovation and Universities (RTI2018-099260-A- I00 to J. Cambroll é and RTI2018-099322-B-100 to X. Moreira).Peer reviewe

Grazing exclosure increases fruit and seed production but reduces seed viability in Myrtus communis

Plants have compensating mechanisms to alleviate the loss of vegetative and reproductive tissues by herbivores. In this study, we evaluated how reproductive traits (size and production of fruit and seed, as well as germination and viability of seeds) of Myrtus communis (myrtle) were affected by goat grazing exclosure of forest understory in the Doñana Natural Park. One hundred and fifty myrtles were selected in three sites with similar environmental characteristics, although with a different length of grazing exclusion: (1) exclosure for 2 years (GE2); (2) exclosure for 3 years (GE3); and (3) long ago grazed plots (GE15): non-accessible to goat for at least 15 years. Fruit production, fruit and seed morphology and seed viability and germination were evaluated. Length of exclosure to goats increased fruit production, mass and volume of the fruits and seed, and endocarp mass. However, seed viability was higher in more recently grazed plots (70–90%) than in GE15 plots (51%). The final balance of viable/germinable seeds produced by an average sized myrtle in each treatment showed that the recently grazed myrtles (GE2) produced nearly five times less seeds (1200) than the myrtles grazed 15 years ago (5500). However, myrtles recovered the ability to produce viable seeds quickly, almost tripling, each year of non-grazing the number of viable/germinable seeds. The results of this study indicated that goat grazing could affect regeneration of myrtle because it reduced reproduction output and the number of viable propagules. Future studies should evaluate other related ecological aspects, such as fruit consumption by potential frugivores and seed dispersal (distance and place of seed deposition)

Endozoochorus seed dispersal by goats: recovery, germinability and emergence of five Mediterranean shrub species

Herbivores can play an important role as seed dispersal vectors, ungulates constituting potential seed dispersal agents of Mediterranean grasses and shrubs. We evaluated the role of domestic goats as seed dispersers of five representative Mediterranean forage shrub species (Cistus albidus L., Phillyrea angustifolia L., Calicotome villosa (Poir.) Link., Rhamnus lycioides L. and Atriplex halimus L.). Following seed ingestion by goats, total faeces were collected at 24-h intervals for five days. The total number of seeds recovered varied among species, with R. lycioides showing the minimum recovery percentage (1.3%) and C. albidus (35.8%), the maximum. Seed recovery was significantly related to seed hardness and length. In most species, the maximum amount of seeds recovered occurred 48-72 h after ingestion. The passage through the goat gut significantly depressed seed germination in C. albidus, C. villosa and A. halimus; inhibited it in R. lycioides and increased it in P. angustifolia. Seedling emergence was significantly lower in intact dung pellets than in broken-down ones, and both significantly lower than in uneaten seeds (control). The results of this study show that goats can potentially favor or inhibit seed dispersal of browsed Mediterranean shrub species. Therefore, goat grazing could be a potential management tool for expanding target shrub species populations or preventing shrub encroachment in undesired areas

Efectividad cualitativa del ganado caprino en la dispersión de especies de frutos secos y carnosos

En este trabajo, se ha evaluado la capacidad de dispersión endozoócora del ganado caprino (raza Payoya) de ocho especies de matorral mediterráneo:Cistus salviifolius, C. libanotis, Halimum halimifolium H. calycinum, Myrtus communis, Phillyrea angustifolia, Pistacia lentiscus y Rhamnuslycioides. Frutos de estas especies fueron ofrecidos a seis cabras estabuladas individualmente. Tras la ingestión, se procedió a recoger las hecesa intervalos de 24 horas. En las heces recuperadas, se determinó el porcentaje de pérdida de semillas (masticación y digestión), distribución de larecuperación de las semillas en el tiempo y la eficacia germinativa tras el paso por el tracto digestivo. Menos del 30% de las semillas ingeridasfueron recuperadas, con diferencias significativas entre las especies. C. salviifolius presentó el mayor porcentaje de recuperación (casi 30%) y P.lentiscus el menor (0%). Esta tasa de recuperación estuvo significativamente relacionada positivamente con la dureza de las semillas. En la mayoríade las especies, la máxima tasa de recuperación se dio entre las 24-72 horas tras la ingestión. El paso por el intestino de las cabras aumentó significativamentela germinación de C. salviifolius, H. halimifolium, H. calycinum y P. angustifolia. Los resultados de este estudio pusieron de manifiestoque el ganado caprino puede favorecer la dispersión de la mayoría de las semillas de especies cistáceas estudiadas e inhibir la dispersión desemillas de frutos carnosos. El conocimiento de los mecanismos de dispersión por ungulados generalistas son aspectos importantes a tener encuenta en los planes de gestión, restauración y conservación de los ecosistemas Mediterráneos

Batch mesophilic anaerobic co-digestion of spent goat batch mesophilic anaerobic co-digestion of spent goat straw bedding and goat cheese whey: Comparison with the mono-digestion of the two sole substrates

4 Tablas.-- 2 FigurasSpent livestock bedding is a valuable resource for the production of green energy (methane) in rural areas. Comparison and evaluation of batch anaerobic digestion and co-digestion of different mixtures of goat straw bedding (SGSB) and goat cheese whey were carried out. Biochemical methane potential (BMP) tests of the 100% SGSB, 95% SGSB-5% whey, 90% SGSB-10% whey, 85% SGSB-15% whey and 100% whey were found to be 423 ± 7, 354 ± 9, 371 ± 2, 293 ± 1, 274 ± 2 mL CH4 g−1 VS. Two different kinetic models were evaluated. The logistic model revealed a decrease in the maximum methane production rate (Rm) from 34.7 ± 1.5 to 14.1 ± 0.9 mL CH4 g−1 VS·d−1 when the percentage of whey in the mixture increased from 0 to 15% as a consequence of the increased ammonia released during the co-digestion of increased concentrations of whey. The lowest value for the maximum methane production predicted by the model (P) was found for 100% whey (274 ± 10 mL CH4 g−1 VS). A two-substrate model was applied to describe the evident existence of rapid and slowly degradable material. Regarding the hydrolysis kinetic constants predicted by this model, considerable increases in the rapid biodegradation stage (krapid) were observed when comparing to the values found for the slow (kslow) biodegradation stage in all the cases tested. The increases between both constants rose from 5 to 42% when the percentage of whey increased.The authors wish to thank to the regional government of Andalucía, Junta de Andalucía, Consejería de Economía y Conocimiento (Project of Excellence RNM-1970) for providing financial support. N.F. Puntano also wishes to thank the academic mobility and exchange program (PIMA). The PIMA program is a mobility initiative for undergraduate students promoted by the Ibero-American States Organization. The authors also wish especially to thank Manuel Vázquez (Sierra del Romero) for his contribution.Peer reviewe

Use of anaerobic digestate as biofertilizer: Another step forward in the valorisation of the invasive brown macroalgae Rugulopteryx okamurae

The rapid and aggressive colonization of the invasive macroalgae Rugulopteryx okamurae on the southern coast of Spain has caused an unprecedented environmental, health and economic impact. At present, the scientific community has focused on the valorisation of R. okamurae waste, as tonnes of collected biomass from this species end up in landfills. In this sense, the aim of this study was to assess, for the first time, the viability of the R. okamurae digestate as biofertilizer to growth the Mediterranean forage species Avena strigosa (black oat). Two anaerobic digestates, derived from the anaerobic digestion of the thermally pre-treated (120 °C; 45 min) and the zeolite-assisted mechanically pre-treated invasive macroalgae, were used in this study. Both digestates were compared with a commercial inorganic nutritive solution. The effect of different fertilizers and water availability on forage height, aerial, root and seed biomass, as well as photosynthetic activity and macro- and micronutrient forage content were studied. The control treatment showed the lowest height at the end of the experiment (0.38 m) and the digestate from the thermally pre-treated macroalgae treatment had the highest one (0.59 m). Final fresh and dry aerial biomass was separately significantly dependent on both fertilizer type and water stress. Final root and seed biomass were not significantly different among the treatments studied. The lowest photosynthetic activity was obtained from the control treatment (3.61 µmol m⁻² s⁻¹), while the highest was reached by the digestate where R. okamurae was thermally pre-treated (4.96 µmol m⁻² s⁻¹). The results of this study show that both digestates tested can be used effectively as organic fertilizer in the cultivation of black oats, obtaining production efficiency values similar (digestate from mechanically pre-treated macroalgae) or higher (digestate from thermally pre-treated macroalgae) than inorganic fertilizer.The authors wish to express their gratitude to the Spanish Ministry of Science and Innovation for providing financial support through the project PID2020-114975RB-100/AEI/10.13039/5011000/11033. M.J. Fernández-Rodríguez is recipient of a “Juan de la Cierva Formación” grant from the Spanish State Research Agency (FJC2020-045654-I). The authors also wish specially to thank F. Ortiz (Fertiprado España) for his advice and M.J. Barraú Párraga for her help in the greenhouse.Peer reviewe

Evaluation of batch mesophilic anaerobic digestion of waste Euro banknotes for methane Production: Preliminary studies and kinetic approach

7 Páginas.-- 1 GráficoThe European Central Bank is striving to find environmentally friendly alternative methods of waste disposal. In 2020, it decided to end the disposal of Waste Euro Banknotes (W€B) in landfills and planned to use them for recycling and/or energy recovery. Despite being recognized as an effective tool in a circular economy model, there are no reported studies on the use of W€B as a substrate in anaerobic digestion (AD). Thus, the aim of this research was to assess the viability of W€B to be converted into high-value-added energy products (mainly methane) through AD. W€B (€10 and €20 denominations) provided by the Bank of Spain were used. Biochemical methane potential (BMP) tests of pre-treated (grinded) and untreated W€B were assessed at mesophilic temperature. The ultimate methane yield was considerably higher for pre-treated W€B (334 ± 23 NmL CH4 g VS-1added) than for untreated W€B (297 ± 14 NmL CH4 g VS-1added). The Logistic or Sigmoidal kinetic model adequately fit the experimental data and allowed for obtaining the kinetic parameters of each case studied. In this sense, an increase of 22.4 % in the maximum methane production rate (Rmax) was observed for the pre-treated W€B (52.5 ± 0.9 mL CH4 (g VS·d)-1 compared to the untreated W€B (16.2 ± 1.8 mL CH4 (g VS·d)-1). According to the obtained results, AD may be a good alternative for the energetic valorization and recycling of W€B.The authors would like to thank the Bank of Spain, especially F. León, F. Arteaga, C. Borrego, J.M. Sánchez, C. García, R. Ortuno, and M. López for technical support and dedication. M.J. Fernández-Rodríguez has been awarded a “Juan de la Cierva Formación” grant from the Spanish State Research Agency (FJC2020-045654-I).Peer reviewe