Influence of Stocking Rate, Grazing Season Length and Dairy Cow Genetic Strain on the Nitrogen Balance of Grass Based Dairy Production Systems

Stocking rate (SR), grazing season (GS) length and Holstein-Friesian (HF) strain can have a profound effect on the productivity of grass-based milk production systems. The optimum SR is that which gives the maximum sustainable economic output of product per unit area. Increasing SR increases output per ha, but also requires increased inputs of feed and fertilizer. Increasing the proportion of grazed grass utilized for milk production improves the economic sustainability of the system (Dillon et al. 2008). Nitrogen (N) use efficiency is one of the key drivers of environmentally and economically sustainable agricultural production systems. Achieving the optimum balance between profitable agriculture and environmental protection is challenging. When production is maximised and output is near equilibrium, all further N inputs are lost to the environment (Rotz et al. 2005), and can result in contamination of waters and contributions to greenhouse gas emissions. A N balance model was used to assess the N use efficiency of components of spring calving grass-based dairy production systems; those components being SR, GS length and HF strain

Going beyond FADN: The use of additional data to gain insights into extension service use across European Union Member States

This paper examines the use of extension services by farm households across eight European Union (EU) Member States, exploring the type of extension service engaged with, the degree of engagement and the type of information sought. The impact of extension on economic, environmental and social sustainability is also considered. European data utilised are those collected from a pilot sample of 820 households in 2015/2016 as part of the EU Framework 7 project FLINT, from which the Irish results are incorporated further with Irish Farm Accountancy Data Network data. The results outline the key contrasts across the countries investigated and suggest that the degree to which households engage with extension services is primarily\ud infl uenced by national policies. In addition, this analysis indicates that the extent of this engagement has implications for sustainability at the farm level. The final conclusions and policy recommendations in this paper support the development of a large-scale version of the FLINT pilot survey

Developing farm-level sustainability indicators for Ireland using the Teagasc National Farm Survey

peer-reviewedIn the context of an expanding, export-dependent agri-food sector, indicators of sustainable development and intensification are necessary to measure, assess and verify the comparative advantage afforded by Ireland’s natural pastoral-based food production systems. Such indicators are also necessary to ensure that we produce more food with less adverse impacts on the Irish environment, climate and society. This article outlines the development of farm-level indicators that refect the multifaceted nature of sustainability, which is encompassed in economic, environmental and social indicators. The role of innovation in farm sustainability was also examined. A comparison of indicators across Irish farm systems showed that dairy farms, followed by tillage farms, tended to be the most economically and socially sustainable farm systems. In relation to greenhouse gas emissions in particular, the top-performing dairy farms, in an economic sense, also tended to be the best-performing farms from an environmental sustainability perspective. This trend was also evident in relation to the adoption of innovative practices on farm, which was found to be strongly correlated with economic performance

Trials of the urban ecologist

A group of scientists describe some of the obstacles encountered and insights gained while carrying out ecological research in and around the city of Indianapolis

Radio Sources from a 31 GHz Sky Survey with the Sunyaev-Zel'dovich Array

We present the first sample of 31-GHz selected sources to flux levels of 1 mJy. From late 2005 to mid 2007, the Sunyaev-Zel'dovich Array (SZA) observed 7.7 square degrees of the sky at 31 GHz to a median rms of 0.18 mJy/beam. We identify 209 sources at greater than 5 sigma significance in the 31 GHz maps, ranging in flux from 0.7 mJy to ~200 mJy. Archival NVSS data at 1.4 GHz and observations at 5 GHz with the Very Large Array are used to characterize the sources. We determine the maximum-likelihood integrated source count to be N(>S) = (27.2 +- 2.5) deg^-2 x (S_mJy)^(-1.18 +- 0.12) over the flux range 0.7 - 15 mJy. This result is significantly higher than predictions based on 1.4-GHz selected samples, a discrepancy which can be explained by a small shift in the spectral index distribution for faint 1.4-GHz sources. From comparison with previous measurements of sources within the central arcminute of massive clusters, we derive an overdensity of 6.8 +- 4.4, relative to field sources.Comment: 13 pages, 5 figure

Bioinspired Helical Microswimmers Based on Vascular Plants

Plant-based bioinspired magnetically propelled helical microswimmers are described. The helical microstructures are derived from spiral water-conducting vessels of different plants, harnessing the intrinsic biological structures of nature. Geometric variables of the spiral vessels, such as the helix diameter and pitch, can be controlled by mechanical stretching for the precise fabrication and consistent performance of helical microswimmers. Xylem vessels of a wide variety of different plants have been evaluated for the consistency and reproducibility of their helical parameters. Sequential deposition of thin Ti and Ni layers directly on the spiral vessels, followed by dicing, leads to an extremely simple and cost-efficient mass-production of functional helical microswimmers. The resulting plant-based magnetic microswimmers display efficient propulsion, with a speed of over 250 μm/s, as well as powerful locomotion in biological media such as human serum. The influence of actuation frequencies on the swimming velocity is investigated. Such use of plant vessels results in significant savings in the processing costs and provides an extremely simple, cost-effective fabrication route for the large-scale production of helical magnetic swimmers

Bioinspired Helical Microswimmers Based on Vascular Plants

Plant-based bioinspired magnetically propelled helical microswimmers are described. The helical microstructures are derived from spiral water-conducting vessels of different plants, harnessing the intrinsic biological structures of nature. Geometric variables of the spiral vessels, such as the helix diameter and pitch, can be controlled by mechanical stretching for the precise fabrication and consistent performance of helical microswimmers. Xylem vessels of a wide variety of different plants have been evaluated for the consistency and reproducibility of their helical parameters. Sequential deposition of thin Ti and Ni layers directly on the spiral vessels, followed by dicing, leads to an extremely simple and cost-efficient mass-production of functional helical microswimmers. The resulting plant-based magnetic microswimmers display efficient propulsion, with a speed of over 250 μm/s, as well as powerful locomotion in biological media such as human serum. The influence of actuation frequencies on the swimming velocity is investigated. Such use of plant vessels results in significant savings in the processing costs and provides an extremely simple, cost-effective fabrication route for the large-scale production of helical magnetic swimmers

Requirements, specifications, and minimal refinement

Refinement is usually employed to produce more concrete versions of a specification, or to add new requirements to it. However, during specification revision one may over-refine, thus incorporating unnecessary requirements. In this paper, we argue that this process can be formalised by the notion of minimal refinements, hence avoiding over-refinement, and prove that this definition is well-behaved theoretically as well as computationall

Bioinspired Helical Microswimmers Based on Vascular Plants

Plant-based bioinspired magnetically propelled helical microswimmers are described. The helical microstructures are derived from spiral water-conducting vessels of different plants, harnessing the intrinsic biological structures of nature. Geometric variables of the spiral vessels, such as the helix diameter and pitch, can be controlled by mechanical stretching for the precise fabrication and consistent performance of helical microswimmers. Xylem vessels of a wide variety of different plants have been evaluated for the consistency and reproducibility of their helical parameters. Sequential deposition of thin Ti and Ni layers directly on the spiral vessels, followed by dicing, leads to an extremely simple and cost-efficient mass-production of functional helical microswimmers. The resulting plant-based magnetic microswimmers display efficient propulsion, with a speed of over 250 μm/s, as well as powerful locomotion in biological media such as human serum. The influence of actuation frequencies on the swimming velocity is investigated. Such use of plant vessels results in significant savings in the processing costs and provides an extremely simple, cost-effective fabrication route for the large-scale production of helical magnetic swimmers

The Sustainable Intensification of the Irish Dairy Sector

peer-reviewedThe concept of sustainability is one of the forefront issues in global agricultural production at present, given mounting pressure to increase food production in both a socially responsible and environmentally friendly way. From an Irish perspective the sustainable intensification of agriculture is of particular relevance given ambitious targets to increase milk production by 50 percent by 2020, in the context of European milk quota removal. Alongside this, environmental targets may be specified, meaning that expansion would have to be achieved in a sustainable way. To evaluate dairy farm-level sustainability a series of indicators are developed here using Teagasc National Farm Survey FADN (Farm Accountancy Data Network) data for Ireland from 2012. Three dimensions, reflecting the multifaceted nature of sustainability (economic, environmental and social) are considered. Given the environmental challenges inherent in the sustainable intensification of agriculture, it is encouraging to observe that the more intensive, top performing farms (in an economic sense) emit relatively less greenhouse gases when compared to their less intensive counterparts. Conversely, the better performing farms in economic terms tend to have higher nitrogen surplus per hectare on average. This is consistent with their higher rates of production intensity but poses a challenge in terms of sustainable expansion. That said this analysis demonstrates that the nitrogen use efficiency of milk production is positively correlated with economic performance, with more intensive farms producing relatively more milk per kg of nitrogen surplus. From a social perspective demography also tends to be correlated with economic performance. These indicators allow for the continued assessment of the sustainability status of Irish farming