Climate change mitigation and productivity gains in livestock supply chains: insights from regional case studies

Livestock can contribute to climate change mitigation by reducing their greenhouse gas emissions and by increasing soil carbon sequestration. Packages of mitigation techniques can bring large environmental benefits as illustrated in six case studies modeled in the Global Livestock Environmental Assessment Model developed by FAO. With feasible technical interventions in livestock production systems, the mitigation potential of each of the selected species, systems and regions ranges from 14 to 41 %. While comparably high mitigation potentials were estimated for ruminant and pig production systems in Asia, Latin America and Africa, large emission reductions can also be attained in dairy systems with already high levels of productivity, in OECD countries. Mitigation interventions can lead to a concomitant reduction in emissions and increase in production, contributing to food security. This is particularly the case for improved feeding practices and better health and herd management practices. Livestock systems also have a significant potential for sequestrating carbon in pasturelands and rangelands through improved management, as illustrated in two of the six case studies in this paper.     

Rapid determination of residues of pesticides in honey by µGC-ECD and GC-MS/MS: Method validation and estimation of measurement uncertainty according to document No. SANCO/12571/2013

A simple and straightforward method for simultaneous determination of residues of 13 pesticides in honey samples (acrinathrin, bifenthrin, bromopropylate, cyhalothrin-lambda, cypermethrin, chlorfenvinphos, chlorpyrifos, coumaphos, deltamethrin, fluvalinate-tau, malathion, permethrin and tetradifon) from different pesticide classes has been developed and validated. The analytical method provides dissolution of honey in water and an extraction of pesticide residues by n-Hexane followed by clean-up on a Florisil SPE column. The extract was evaporated and taken up by a solution of an injection internal standard (I-IS), ethion, and finally analyzed by capillary gas chromatography with electron capture detection (GC-µECD). Identification for qualitative purpose was conducted by gas chromatography with triple quadrupole mass spectrometer (GC-MS/MS). A matrix-matched calibration curve was performed for quantitative purposes by plotting the area ratio (analyte/I-IS) against concentration using a GC-µECD instrument. According to document No. SANCO/12571/2013, the method was validated by testing the following parameters: linearity, matrix effect, specificity, precision, trueness (bias) and measurement uncertainty. The analytical process was validated analyzing blank honey samples spiked at levels equal to and greater than 0.010 mg/kg (limit of quantification). All parameters were satisfactorily compared with the values established by document No. SANCO/12571/2013. The analytical performance was verified by participating in eight multi-residue proficiency tests organized by BIPEA, obtaining satisfactory z-scores in all 70 determinations. Measurement uncertainty was estimated according to the top-down approaches described in Appendix C of the SANCO document using the within-laboratory reproducibility relative standard deviation combined with laboratory bias using the proficiency test data.     

Phytoremediation of phenol using Vicia sativa L. plants and its antioxidative response

Common vetch (Vicia sativa L.) is a legume species with an extensive agricultural use. However, the phytoremediation potentiality of this species has not been sufficiently explored because little is known about its resistance to inorganic and organic pollutants. In the present work, phenol tolerance of common vetch was assayed at different stages of growth. Germination index and germination rate decreased only at high phenol concentrations (250 and 500 mg L(-1)), whereas 30-day-old plants were able to tolerate this pollutant, with high removal efficiencies. The activities of antioxidative enzymes, such as peroxidase (POD) and ascorbate peroxidase, increased significantly with the highest phenol concentration, whereas superoxide dismutase activity, malondialdehyde, and H(2)O(2) levels remained unaltered. Besides, an increase in two basic isoforms of POD was observed in plants treated with phenol. The results suggested that common vetch has an efficient protection mechanism against phenol-induced oxidative damage. Moreover, it could tolerate and remove high phenol concentrations, avoiding serious phytotoxic effects. Thus, V. sativa could be considered an interesting tool in the field of phytoremediation.     

The use of olive-mill waste compost to promote the plant vegetation cover in a trace-element-contaminated soil

The applicability of a mature compost as a soil amendment to promote the growth of native species for the phytorestoration of a mine-affected soil from a semi-arid area (SE Spain), contaminated with trace elements (As, Cd, Cu, Mn, Pb and Zn), was evaluated in a 2-year field experiment. The effects of an inorganic fertiliser were also determined for comparison. Bituminaria bituminosa was the selected native plant since it is a leguminous species adapted to the particular local pedoclimatic conditions. Compost addition increased total organic-C concentrations in soil with respect to the control and fertiliser treatments, maintained elevated available P concentrations throughout the duration of the experiment and stimulated soil microbial biomass, while trace elements extractability in the soil was rather low due to the calcareous nature of the soil and almost unaltered in the different treatments. Tissue concentrations of P and K in B. bituminosa increased after the addition of compost, associated with growth stimulation. Leaf Cu concentration was also increased by the amendments, although overall the trace elements concentrations can be considered non-toxic. In addition, the spontaneous colonisation of the plots by a total of 29 species of 15 different families at the end of the experiment produced a greater vegetation cover, especially in plots amended with compost. Therefore, the use of compost as a soil amendment appears to be useful for the promotion of a vegetation cover and the phytostabilisation of moderately contaminated soils under semi-arid conditions.     

The economic value of water use: implications for implementing the Water Framework Directive in Scotland

The European Union Water Framework Directive (WFD) enshrines several economic principles in pursuit of 'good ecological status' for Europe's waters and rationalising water use in society. The implicit principle of maximising the social value from use of a scarce resource is reminiscent of the debate about treating water as an economic good, which has competing uses in society. This paper locates the debate about the economic value of water in the requirements of WFD. Specifically, we consider the implications of national reporting requirements for the economic characterisation report that stress the identification of relative value derived from use. As part of the Scottish contribution to the UK reporting exercise, we use a range of secondary data sources to derive economic values for water on a sector basis. We suggest whether the implications of different water values can be followed through in the WFD.     

Geochemical and ecological significance of soil lipids under Rhododendron ponticum stands

The bio-geographical significance of Rhododendron ponticum spp. baeticum (Ericaceae) as a relict species is well recognized. However, out of its native habitat it is an invasive exotic considered a major threat to natural ecosystems in areas of Atlantic Western Europe. The studies on the impact of Rhododendron influence on soil organic matter composition and associated ecological implications, i.e. presence of bioactive compounds with ecological significance, are limited. This work describes the soil lipid assemblage in three sites under Rhododendron stands and adjacent sites with deciduous oak (Quercus canariensis), both in their native habitats in Southern Spain (Sierra de Luna, Cádiz). The results are discussed in terms of organic matter dynamics and the presence of molecules that may be associated with Rhododendron invasive success. The soils are acid Xerochrepts formed on siliceous sands. Composite soil samples were taken at two depths (0?C10?cm and 10?C20?cm) and soxhlet extracted with a dichloromethane-methanol mixture (3:1). Soil lipid assemblage was studied by GC/MS after fractionation and appropriate derivatization of extracts. The qualitative chemical composition of soil extractable lipids under Rhododendron is reported here for the first time. Our results show that soil n-alkane and fatty acid distributions are compatible with an input from plant epicuticular waxes, as well as with the occurrence of selective preservation of long-chain fatty acids with depth. The pattern of short-chain n-alkanes found in surface samples indicates an anthropogenic contamination threat from nearby industrialized areas of ??Campo de Gibraltar??. The presence of branched iso and anteiso C₁₅ and C₁₇, ??-hydroxy fatty acids and the sterol brassicasterol points to high microbial soil activity. Finally, the pentacyclic triterpenes taraxerone and taraxerol were detected in soils with Rhododendron but not with Quercus. These are known bio-active plant compounds and could be related with the effectiveness of Rhododendron as an invasive exotic species.     

Steam gasification of waste tyre: Influence of process temperature on yield and product composition

An experimental survey of waste tyre gasification with steam as oxidizing agent has been conducted in a continuous bench scale reactor, with the aim of studying the influence of the process temperature on the yield and the composition of the products; the tests have been performed at three different temperatures, in the range of 850–1000 °C, holding all the other operational parameters (pressure, carrier gas flow, solid residence time). The experimental results show that the process seems promising in view of obtaining a good quality syngas, indicating that a higher temperature results in a higher syngas production (86 wt%) and a lower char yield, due to an enhancement of the solid–gas phase reactions with the temperature. Higher temperatures clearly result in higher hydrogen concentrations: the hydrogen content rapidly increases, attaining values higher than 65% v/v, while methane and ethylene gradually decrease over the range of the temperatures; carbon monoxide and dioxide instead, after an initial increase, show a nearly constant concentration at 1000 °C. Furthermore, in regards to the elemental composition of the synthesis gas, as the temperature increases, the carbon content continuously decreases, while the oxygen content increases; the hydrogen, being the main component of the gas fraction and having a small atomic weight, is responsible for the progressive reduction of the gas density at higher temperature.