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Potential of legume-based grassland-livestock systems in Europe
European grassland-based livestock production systems
face the challenge of producing more meat and
milk to meet increasing world demands and to achieve
this using fewer resources. Legumes offer great potential
for achieving these objectives. They have numerous
features that can act together at different stages in
the soilâplantâanimalâatmosphere system, and these
are most effective in mixed swards with a legume proportion
of 30â50%. The resulting benefits include
reduced dependence on fossil energy and industrial
N-fertilizer, lower quantities of harmful emissions to
the environment (greenhouse gases and nitrate), lower
production costs, higher productivity and increased
protein self-sufficiency. Some legume species offer
opportunities for improving animal health with less
medication, due to the presence of bioactive secondary
metabolites. In addition, legumes may offer an adaptation
option to rising atmospheric CO2 concentrations
and climate change. Legumes generate these benefits
at the level of the managed land-area unit and also at
the level of the final product unit. However, legumes
suffer from some limitations, and suggestions are made
for future research to exploit more fully the opportunities
that legumes can offer. In conclusion, the development
of legume-based grasslandâlivestock systems
undoubtedly constitutes one of the pillars for more
sustainable and competitive ruminant production systems,
and it can be expected that forage legumes will
become more important in the future
Impact of droughts on the carbon cycle in European vegetation : a probabilistic risk analysis using six vegetation models
Peer reviewedPublisher PD
The 4 per 1000 initiative.
Soil organic matter is at the nexus of global challenges: food security, climate change adaptation and mitigation, soil security. The 4 per 1000 initiative, launched at the Climate COP21 within the Lima-Paris Action Agenda proposes to increase soil organic carbon (SOC) stocks to simultaneously address all these challenges. It directly addresses three sustainable development goals: SDG2 ?no hunger?, SDG13 ?Climate action?, and SDG15 ?Life on land? and indirectly concerns several others. The initiative targets agricultural soils in priority, which are often the most degraded soils and because of the high expected benefits in terms of soil fertility and hence of productivity. A range of agricultural practices are available that allow to increase SOC stocks while ensuring a resilient, productive and environmentally friendly agriculture, so that a large-scale deployment can be aimed at. Here, we review and discuss the main limits and criticisms addressed to the 4 per 1000 initiative
Evaluating the Potential of Legumes to Mitigate NO Emissions From Permanent Grassland Using Process-Based Models
A potential strategy for mitigating nitrous oxide (NO) emissions from permanent grasslands is the partial substitution of fertilizer nitrogen (N) with symbiotically fixed nitrogen (N) from legumes. The input of N reduces the energy costs of producing fertilizer and provides a supply of nitrogen (N) for plants that is more synchronous to plant demand than occasional fertilizer applications. Legumes have been promoted as a potential NO mitigation strategy for grasslands, but evidence to support their efficacy is limited, partly due to the difficulty in conducting experiments across the large range of potential combinations of legume proportions and fertilizer N inputs. These experimental constraints can be overcome by biogeochemical models that can vary legumeâfertilizer combinations and subsequently aid the design of targeted experiments. Using two variants each of two biogeochemical models (APSIM and DayCent), we tested the NO mitigation potential and productivity of full factorial combinations of legume proportions and fertilizer rates for five temperate grassland sites across the globe. Both models showed that replacing fertilizer with legumes reduced NO emissions without reducing productivity across a broad range of legumeâfertilizer combinations. Although the models were consistent with the relative changes of NO emissions compared to the baseline scenario (200 kg N ha yr; no legumes), they predicted different levels of absolute NO emissions and thus also of absolute NO emission reductions; both were greater in DayCent than in APSIM. We recommend confirming these results with experimental studies assessing the effect of clover proportions in the range 30â50% and â€150 kg N ha yr input as these were identified as bestâbet climate smart agricultural practices
Quality control of CarboEurope flux data â Part I: Footprint analyses to evaluate sites in forest ecosystems
International audienceWe applied a site evaluation approach combining Lagrangian Stochastic footprint modelling with a quality assessment approach for eddy-covariance data to 25 forested sites of the CarboEurope-IP network. The analysis addresses the spatial representativeness of the flux measurements, instrumental effects on data quality, spatial patterns in the data quality, and the performance of the coordinate rotation method. Our findings demonstrate that application of a footprint filter could strengthen the CarboEurope-IP flux database, since only one third of the sites is situated in truly homogeneous terrain. Almost half of the sites experience a significant reduction in eddy-covariance data quality under certain conditions, though these effects are mostly constricted to a small portion of the dataset. Reductions in data quality of the sensible heat flux are mostly induced by characteristics of the surrounding terrain, while the latent heat flux is subject to instrumentation-related problems. The Planar-Fit coordinate rotation proved to be a reliable tool for the majority of the sites using only a single set of rotation angles. Overall, we found a high average data quality for the CarboEurope-IP network, with good representativeness of the measurement data for the specified target land cover types
Nitrous oxide emissions from European agriculture - An analysis of variability and drivers of emissions from field experiments
Nitrous oxide emissions from a network of agricultural experiments in Europe were used to explore the relative importance of site and management controls of emissions. At each site, a selection of management interventions were compared within replicated experimental designs in plot-based experiments. Arable experiments were conducted at Beano in Italy, El Encin in Spain, Foulum in Denmark, LogĂ„rden in Sweden, Maulde in Belgium, Paulinenaue in Germany, and Tulloch in the UK. Grassland experiments were conducted at Crichton, Nafferton and Peaknaze in the UK, Gödöllö in Hungary, Rzecin in Poland, Zarnekow in Germany and Theix in France. Nitrous oxide emissions were measured at each site over a period of at least two years using static chambers. Emissions varied widely between sites and as a result of manipulation treatments. Average site emissions (throughout the study period) varied between 0.04 and 21.21 kg N<sub>2</sub>O-N ha<sup>â1</sup> yr<sup>â1</sup>, with the largest fluxes and variability associated with the grassland sites. Total nitrogen addition was found to be the single most important determinant of emissions, accounting for 15% of the variance (using linear regression) in the data from the arable sites (<i>p</i> < 0.0001), and 77% in the grassland sites. The annual emissions from arable sites were significantly greater than those that would be predicted by IPCC default emission factors. Variability of N<sub>2</sub>O emissions within sites that occurred as a result of manipulation treatments was greater than that resulting from site-to-site and year-to-year variation, highlighting the importance of management interventions in contributing to greenhouse gas mitigation
An appraisal of carbon footprint of milk from commercial grass-based dairy farms in Ireland according to a certified life cycle assessment methodology
Quality Control of CarboEurope Flux Data - Part I: Coupling Footprint Analyses with Flux Data Quality Assessment to Evaluate Sites in Forest Ecosystems
We applied a site evaluation approach combining Lagrangian Stochastic footprint modelling with a quality assessment approach for eddy-covariance data to 25 forested sites of the CarboEurope-IP network. The analysis addresses the spatial representativeness 5 of the flux measurements, instrumental effects on data quality, spatial patterns in the data quality, and the performance of the coordinate rotation method. Our findings demonstrate that application of a footprint filter could strengthen the CarboEurope-IP flux database, since only one third of the sites is situated in truly homogeneous terrain. Almost half of the sites experience a significant reduction in eddy-covariance data 10 quality under certain conditions, though these effects are mostly constricted to a small portion of the dataset. Reductions in data quality of the sensible heat flux are mostly induced by characteristics of the surrounding terrain, while the latent heat flux is subject
to instrumentation-related problems. The Planar-Fit coordinate rotation proved to be a reliable tool for the majority of the sites using only a single set of rotation angles. 15 Overall, we found a high average data quality for the CarboEurope-IP network, with good representativeness of the measurement data for the specified target land cover types.JRC.H.2-Air and Climat
Effect of Stocking Rate on Soil-Atmosphere CH4 Flux during Spring Freeze-Thaw Cycles in a Northern Desert Steppe, China
BACKGROUND: Methane (CH(4)) uptake by steppe soils is affected by a range of specific factors and is a complex process. Increased stocking rate promotes steppe degradation, with unclear consequences for gas exchanges. To assess the effects of grazing management on CH(4) uptake in desert steppes, we investigated soil-atmosphere CH(4) exchange during the winter-spring transition period. METHODOLOGY/MAIN FINDING: The experiment was conducted at twelve grazing plots denoting four treatments defined along a grazing gradient with three replications: non-grazing (0 sheep/ha, NG), light grazing (0.75 sheep/ha, LG), moderate grazing (1.50 sheep/ha, MG) and heavy grazing (2.25 sheep/ha, HG). Using an automatic cavity ring-down spectrophotometer, we measured CH(4) fluxes from March 1 to April 29 in 2010 and March 2 to April 27 in 2011. According to the status of soil freeze-thaw cycles (positive and negative soil temperatures occurred in alternation), the experiment was divided into periods I and II. Results indicate that mean CH(4) uptake in period I (7.51 ”g CH(4)-C m(-2) h(-1)) was significantly lower than uptake in period II (83.07 ”g CH(4)-C m(-2) h(-1)). Averaged over 2 years, CH(4) fluxes during the freeze-thaw period were -84.76 ”g CH(4)-C m(-2) h(-1) (NG), -88.76 ”g CH(4)-C m(-2) h(-1) (LG), -64.77 ”g CH(4)-C m(-2) h(-1) (MG) and -28.80 ”g CH(4)-C m(-2) h(-1) (HG). CONCLUSIONS/SIGNIFICANCE: CH(4) uptake activity is affected by freeze-thaw cycles and stocking rates. CH(4) uptake is correlated with the moisture content and temperature of soil. MG and HG decreases CH(4) uptake while LG exerts a considerable positive impact on CH(4) uptake during spring freeze-thaw cycles in the northern desert steppe in China
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