Mitigation of nitrous oxide emissions in grazing systems through nitrification inhibitors: a meta-analysis

Grasslands are the largest contributor of nitrous oxide (N2O) emissions in the agriculture sector due to livestock excreta and nitrogen fertilizers applied to the soil. Nitrification inhibitors (NIs) added to N input have reduced N2O emissions, but can show a range of efficiencies depending on climate, soil, and management conditions. A meta-analysis study was conducted to investigate the factors that influence the efficiency of NIs added to fertilizer and excreta in reducing N2O emissions, focused on grazing systems. Data from peer-reviewed studies comprising 2164 N2O emission factors (EFs) of N inputs with and without NIs addition were compared. The N2O EFs varied according to N source (0.0001-8.25%). Overall, NIs reduced the N2O EF from N addition by 56.6% (51.1-61.5%), with no difference between NI types (Dicyandiamide-DCD; 3,4-Dimethylpyrazole phosphate-DMPP; and Nitrapyrin) or N source (urine, dung, slurry, and fertilizer). The NIs were more efficient in situations of high N2O emissions compared with low; the reduction was 66.0% when EF > 1.5% of N applied compared with 51.9% when EF 10 kg ha(-1). NIs were less efficient in urine with lower N content (<= 7 g kg(-1)). NI efficiency was negatively correlated with soil bulk density, and positively correlated with soil moisture and temperature. Better understanding and management of NIs can optimize N2O mitigation in grazing systems, e.g., by mapping N2O risk and applying NI at variable rate, contributing to improved livestock sustainability

Designing grazing systems that enhance the health of New Zealand high-country grasslands

More sustainable pastoral livestock production systems are required to face the challenge of reconciling agricultural production and environmental impact. Although the need for more holistic approaches, such as systems thinking and design theory, is acknowledged, systemic research applying those theories to create healthier systems remains underexplored. A multiple steps holistic approach involving modelling, geographic information systems, and decision-making analysis was used to design, assess, and contrast alternative scenarios that represent distinct grazing management to the current grazing management of a high-country station in New Zealand used as a case study to enhance grassland health. Three alternative scenarios were created, and five main parameters used to assess grassland health were obtained from the evaluation of the designed scenarios. From all the parameters, soil erosion control and increased production were ranked as the most and least important, respectively, to be considered in the design process. A multi-criteria evaluation defined that the best-compromise scenario to enhance grassland health is the scenario with lower soil erosion, as a result of applying adaptive and flexible management at the paddock level, the lower total emission of greenhouse gases (only sheep herd grazing), and greater profitability (due to production costs reduction, as cattle were removed from the station), compared to the ‘status quo’. Our design methodology produced a variety of alternatives that enhanced the health of grasslands in different parameters while still maintaining or increasing profitability. The use of multi-criteria evaluation facilitated the decision of the most contextualised and best-compromise scenario for New Zealand high country grasslands

Comparing the environmental efficiency of milk and beef production through life cycle assessment of interconnected cattle systems

Dairy production has a substantial environmental impact. Currently, most studies analysing the environmental burdens of milk production employ attributional Life Cycle Assessment (LCA), for cradle to farm-gate analysis of dairy systems. This approach calculates environmental footprints per kg fat and protein corrected milk (FPCM). However, milk and beef production are inherently interconnected, and a narrow focus on milk production neglects wider synergies and trade-offs across cattle systems, outside dairy farm boundaries. For the first time, we applied an expanded boundary LCA of coupled dairy and beef production in Latin America, considering 1 kg FPCM plus 100 g of beef as functional unit (FU) to reflect the current global beef:milk demand ratio and taking into account the complexities of Costa Rican cattle production systems. Boundaries encompassed fattening of surplus dairy calves and incurred or avoided suckler-beef production needed to deliver the FU. A database of 552 Costa Rican farms (203 beef and 349 dairy farms) was analysed using a farm LCA model to generate results across five impact categories (Global Warming Potential – GWP; Eutrophication; Acidification; Abiotic Resource Depletion; and Land Occupation - LO). Normalised scores indicated that cattle systems contribute most strongly to per capita GWP and LO burdens. Cradle to farm-gate attributional LCA showed that milk produced by dual-purpose farms had the largest GWP and LO footprints, whilst specialist farms had the smallest footprints, per kg FPCM. The expanded boundary LCA showed that dual-purpose farms generated smaller GWP footprints per kg FPCM plus 100 g beef than specialised dairy farms, though still required more land. Key factors were the herd structure, influencing the amount of beef produced, and milk yields per animal, reflecting the level of dairy specialisation. This new evidence on the environmental efficiency of cattle production systems emphasises the imperative to consider both milk and beef production as well as multiple environmental pressures across interconnected milk and beef production systems when designing sustainable intensification mitigation strategies

Neurofunctional changes after a single mirror therapy intervention in chronic ischemic stroke

<p><b>Background:</b> Mirror therapy (MT) is becoming an alternative rehabilitation strategy for various conditions, including stroke. Although recent studies suggest the positive benefit of MT in chronic stroke motor recovery, little is known about its neural mechanisms.</p> <p><b>Purpose:</b> To identify functional brain changes induced by a single MT intervention in ischemic stroke survivors, assessed by both transcranial magnetic stimulation (TMS) and functional magnetic resonance imaging (fMRI).</p> <p><b>Materials and methods:</b> TMS and fMRI were used to investigate 15 stroke survivors immediately before and after a single 30-min MT session.</p> <p><b>Results:</b> We found statistically significant increase in post-MT motor evoked potential (MEP) amplitude (increased excitability) from the affected primary motor cortex (M1), when compared to pre-MT MEP. Post-MT fMRI maps were associated with a more organized and constrained pattern, with a more focal M1 activity within the affected hemisphere after MT, limited to the cortical area of hand representation. Furthermore, we find a change in the balance of M1 activity toward the affected hemisphere. In addition, significant correlation was found between decreased fMRI β-values and increased MEP amplitude post-MT, in the affected hemisphere.</p> <p><b>Conclusion:</b> Our study suggests that a single MT intervention in stroke survivors is related to increased MEP of the affected limb, and a more constrained activity of the affected M1, as if activity had become more constrained and limited to the affected hemisphere.</p

Comparing the environmental efficiency of milk and beef production through life cycle assessment of interconnected cattle systems

peer-reviewedThe full text of this article will not be available in ULIR until the embargo expires on the 08/09/2020Dairy production has a substantial environmental impact. Currently, most studies analysing the environmental burdens of milk production employ attributional Life Cycle Assessment (LCA), for cradle to farm-gate analysis of dairy systems. This approach calculates environmental footprints per kg fat and protein corrected milk (FPCM). However, milk and beef production are inherently interconnected, and a narrow focus on milk production neglects wider synergies and trade-offs across cattle systems, outside dairy farm boundaries. For the first time, we applied an expanded boundary LCA of coupled dairy and beef production in Latin America, considering 1 kg FPCM plus 100 g of beef as functional unit (FU) to reflect the current global beef:milk demand ratio and taking into account the complexities of Costa Rican cattle production systems. Boundaries encompassed fattening of surplus dairy calves and incurred or avoided suckler-beef production needed to deliver the FU. A database of 552 Costa Rican farms (203 beef and 349 dairy farms) was analysed using a farm LCA model to generate results across five impact categories (Global Warming Potential – GWP; Eutrophication; Acidification; Abiotic Resource Depletion; and Land Occupation - LO). Normalised scores indicated that cattle systems contribute most strongly to per capita GWP and LO burdens. Cradle to farm-gate attributional LCA showed that milk produced by dual-purpose farms had the largest GWP and LO footprints, whilst specialist farms had the smallest footprints, per kg FPCM. The expanded boundary LCA showed that dual-purpose farms generated smaller GWP footprints per kg FPCM plus 100 g beef than specialised dairy farms, though still required more land. Key factors were the herd structure, influencing the amount of beef produced, and milk yields per animal, reflecting the level of dairy specialisation. This new evidence on the environmental efficiency of cattle production systems emphasises the imperative to consider both milk and beef production as well as multiple environmental pressures across interconnected milk and beef production systems when designing sustainable intensification mitigation strategies