Integrating local knowledge with science and technology in management of soil,water and nutrients: implications for management of natural capital for sustainable rural livelihoods

Harnessing local knowledge and practices for sustainable management of soil, water and nutrients is important for sustainable development. This work aims to understand soil productivity in traditional open-ridging practices and integrate scientific ideas and technologies into traditional practices for enhancing management of soil productivity. Participatory assessments, household surveys, field experiments, observations and analyses of outcomes were used. Participatory assessments revealed declining natural soil fertility and maize productivity over time, a concern reiterated by 82.5% of respondents. Evaluation of ridge tillage practices showed that bean yields were significantly (p?<?0.05) higher by 19–35% in traditional open ridges and increased by 23–38% when ties were integrated. Integration of fertilizers resulted in significantly (p?<?0.05) higher subsequent maize yields in tied ridges than in traditional open ridge and flat cultivation practices. Improved integrated tillage practices resulted in increased soil and water conservation, soil fertility and crop tolerance to prolonged no-rainfall spells. National development policies should create enabling environments for smallholder farmers to integrate modern knowledge and technologies with their traditional knowledge and practices in land management for high and sustained quality of natural capital for secure and sustainable livelihoods.     

Particleboard panels made with sugarcane bagasse waste—an exploratory study

The reuse of natural fibers, in order to manufacture a new product, is already becoming popular due to the generation of a series of advantages in social areas. Sugarcane bagasse is a set of tangled fibers of cellulose, produced in large quantities due to increased acreage and industrialization of sugarcane resulting from public and private investments in production aimed for the alcohol industry. The aim of this study was to evaluate the feasibility of producing sheet timber manufacture from the sugarcane bagasse, analyzing mechanical strength properties. A form of metal sheet for the molding of 12 specimens based on sugarcane bagasse and industrialized resin was made. Soon after molding, specimens were submitted to a three-point bending test, with the aid of a press. The analysis of the results allowed to conclude that the tensile strength and the modulus of elasticity did not obtain the minimum values recommended by the standard. The tensile strength must be improved to allow panels to be useful for ordinary strength applications.

     

Connectivity between countries established by landbirds and raptors migrating along the African–Eurasian flyway

The conservation of long-distance migratory birds requires coordination between the multiple countries connected by the movements of these species. The recent expansion of tracking studies is shedding new light on these movements, but much of this information is fragmented and inaccessible to conservation practitioners and policy makers. We synthesized current knowledge on the connectivity established between countries by landbirds and raptors migrating along the African–Eurasian flyway. We reviewed tracking studies to compile migration records for 1229 individual birds, from which we derived 544 migratory links, each link corresponding to a species’ connection between a breeding country in Europe and a nonbreeding country in sub-Saharan Africa. We used these migratory links to analyze trends in knowledge over time and spatial patterns of connectivity per country (across species), per species (across countries), and at the flyway scale (across all countries and all species). The number of tracking studies available increased steadily since 2010 (particularly for landbirds), but the coverage of existing tracking data was highly incomplete. An average of 7.5% of migratory landbird species and 14.6% of raptor species were tracked per country. More data existed from central and western European countries, and it was biased toward larger bodied species. We provide species- and country-level syntheses of the migratory links we identified from the reviewed studies, involving 123 populations of 43 species, migrating between 28 European and 43 African countries. Several countries (e.g., Spain, Poland, Ethiopia, Democratic Republic of Congo) are strategic priorities for future tracking studies to complement existing data, particularly on landbirds. Despite the limitations in existing tracking data, our data and results can inform discussions under 2 key policy instruments at the flyway scale: the African–Eurasian Migratory Landbirds Action Plan and the Memorandum of Understanding on the Conservation of Migratory Birds of Prey in Africa and Eurasia.     

Statistical analysis in estimating probable concentrations of representative chemical species in leachate: a solution for the source term of new or unmonitored landfills

Journal of Material Cycles and Waste Management - Leakage modeling can be crucial for environmental management and control of waste landfills. However, defining boundary conditions for these models...     

Bacterial communities of the marine sponges Hymeniacidon heliophila and Polymastia janeirensis and their environment in Rio de Janeiro, Brazil

In this study we performed a survey of the bacterial communities associated with the Western Atlantic demosponges Hymeniacidon heliophila and Polymastia janeirensis, based on 16S rRNA sequencing and transmission electron microscopy (TEM). We compared diversity and composition of the sponge-associated bacteria to those of environmental bacteria, represented by free-living bacterioplankton and by bacteria attached to organic particulate matter in superficial sediments. Partial bacterial 16S rRNA sequences from seawater, sediment, and sponges were retrieved by PCR, cloning, and sequencing. Sequences were subjected to rarefaction analyses, phylogenetic tree construction, and LIBSHUFF quantitative statistics to verify coverage and similarity between libraries. Community structure of the free-living bacterioplankton was phylogenetically different from that of the sponge-associated bacterial assemblages. On the other hand, some sediment-attached bacteria were also found in the sponge bacterial community, indicating that sponges may incorporate bacteria together with sediment particles. Rare and few prokaryotic morphotypes were found in TEM analyses of sponge mesohyl matrix of both species. Molecular data indicate that bacterial richness and diversity decreases from bacterioplankton, to particulate organic sediment, and to H. heliophila and P. janeirensis. Sponges from Rio de Janeiro harbor a pool of novel and exclusive sponge-associated bacterial taxa. Sponge-associated bacterial communities are composed of both taxons shared by many sponge groups and by species-specific bacteria.     

Agricultural waste from the tequila industry as substrate for the production of commercially important enzymes

Approximately 1 million tons of Agave tequilana plants are processed annually by the Mexican Tequila industry generating vast amounts of agricultural waste. The aim of this study was to investigate the potential use of Agave tequilana waste as substrate for the production of commercially important enzymes. Two strains of Aspergillus niger (CH-A-2010 and CH-A-2016), isolated from agave fields, were found to grow and propagate in submerged cultures using Agave tequilana waste as substrate. Isolates showed simultaneous extracellular inulinase, xylanase, pectinase, and cellulase activities. Aspergillus CH-A-2010 showed the highest production of inulinase activity (1.48 U/ml), whereas Aspergillus niger CH-A-2016 produced the highest xylanase (1.52 U/ml) and endo-pectinase (2.7U/ml) activities. In both cases production of enzyme activities was significantly higher on Agave tequilana waste than that observed on lemon peel and specific polymeric carbohydrates. Enzymatic hydrolysis of raw A. tequilana stems and leaves, by enzymes secreted by the isolates yielded maximum concentrations of reducing sugars of 28.2 g/l, and 9.9 g/l respectively. In conclusion, Agave tequilana waste can be utilized as substrate for the production of important biotechnological enzymes.     

Metals and emerging contaminants in groundwater and human health risk assessment

Environmental Science and Pollution Research - Groundwaters are normally consumed without previous treatment and therefore the monitoring of contaminants in order to guarantee its safety is...     

Macroalgae mitigation potential for fish aquaculture effluents: an approach coupling nitrogen uptake and metabolic pathways using Ulva rigida and Enteromorpha clathrata

Aquaculture effluents are rich in nitrogen compounds that may enhance local primary productivity, leading to the development of algae blooms. The goal of this study was to assess the potential use of naturally occurring green macroalgae (Ulva and Enteromorpha) as bioremediators for nitrogen-rich effluents from a fish aquaculture plant, by evaluating their respective uptake dynamics under controlled conditions. Ulva and Enteromorpha were incubated separately in aquaculture effluent from a local pilot station. Algae tissue and water samples were collected periodically along 4 h. For each sample, nitrate, nitrite, and ammonia concentrations were quantified in the effluent, while internal algae reserve pools and nitrate reductase activity (NRA) were determined within the algae tissues. Both macroalgae absorbed all dissolved inorganic nitrogen compounds in less than 1 h, favoring ammonia over nitrate. Ulva stored nitrate temporarily as an internal reserve and only used it after ammonia availability decreased, whereas Enteromorpha stored and metabolized ammonia and nitrate simultaneously. These distinct dynamics of ammonia and nitrate uptake supported an increase in NRA during the experiment. This study supports the hypothesis that Ulva or Enteromorpha can be used as bioremediators in aquaculture effluents to mitigate excess of dissolved inorganic nitrogen.     

Environmental effects of anticholinesterasic therapeutic drugs on a crustacean species,Daphnia magna

The presence of pharmaceutical drugs in the environment is an important field of toxicology, since such residues can cause deleterious effects on exposed biota. This study assessed the ecotoxicological acute and chronic effects of two anticholinesterasic drugs, neostigmine and pyridostigmine in Daphnia magna. Our study calculated 48 h-EC₅₀ values for the immobilization assay of 167.7 μg L^?1 for neostigmine and 91.3 μg L^?1 for pyridostigmine. In terms of feeding behavior, we calculated a 5 h-EC₅₀ for filtration rates of 7.1 and 0.2 μg L^?1 for neostigmine and pyridostigmine, respectively; for the ingestion rates, the calculated EC₅₀ values were, respectively, 7.5 and 0.2 μg L^?1 for neostigmine and pyridostigmine. In the reproduction assay, the most affected parameter was the somatic growth rate (LOECs of 21.0 and 2.9 μg L^?1 for neostigmine and pyridostigmine, respectively), followed by the fecundity (LOECs of 41.9 and 11.4 μg L^?1 for neostigmine and pyridostigmine, respectively). We also determined a 48 h-IC₅₀ for cholinesterase activity of 1.7 and 4.5 μg L^?1 for neostigmine and pyridostigmine, respectively. These results demonstrated that both compounds are potentially toxic for D. magna at concentrations in the order of the μg L^?1.     

Nitrogen oxides and ozone in Portugal: trends and ozone estimation in an urban and a rural site

Environmental Science and Pollution Research - This study provides an analysis of the spatial distribution and trends of NO, NO2 and O3 concentrations in Portugal between 1995 and 2010....