3,710 research outputs found

    Nutrient budgets on organic farms: a review of published

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    This report was presented at the UK Organic Research 2002 Conference. On organic farms it is important that a balance between inputs and outputs of nutrients is achieved. This paper collates nutrient budgets collated at the farm scale for 88 farms in 9 temperate countries. The majority of budgets were compiled for dairy farms (56). All the nitrogen budgets showed an N surplus (average 83 kg N ha-1 year-1). The phosphorus (P) and potassium (K) budgets showed both surpluses and deficits (average 3.4 kg P ha-1 year-1; 13.7 kg K ha-1 year-1). For all nutrients as nutrient inputs increased the surplus increased more significantly than the nutrient outputs. Overall, the data illustrate the diversity of management systems in place on organic farms, which consequently lead to significant variability in nutrient use efficiency and potential nutrient sustainability between farms. There are opportunities for almost all organic farmers to improve the efficiency of nutrient cycling on the farm and increase short-term productivity and long-term sustainability

    Nutrient cycling on organic farms

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    This paper examines the sustainability of nutrient cycling on organic farms. After a brief consideration of the principles of nutrient cycling in organic agriculture, data on soil P and K indices and farm nutrient budgets is used to assess the integrity of nutrient cycling, including some consideration of losses to the environment. An attempt is made to assess the wider sustainability of organic farming in the context of the limited amount of recycling possible

    Oil and Gas Industry Resisting New Regulations

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    Modelling Monetary Policy Reaction Functions

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    This paper considers how monetary policy is modelled currently, with particular reference to the Reserve Bank of New Zealand’s dynamic stochastic general equilibrium model: Kiwi Inflation Targeting Technology (K.I.T.T.). By considering the role and objectives of monetary policy along with its dynamic effects, it is suggested that monetary policy might better be modelled using micro-foundations, where the path of monetary policy is determined by an optimising central bank. In the context of the New Zealand economy, the monetary authority’s optimisation problem is postulated and developed. To conclude, an alternative monetary policy reaction function is suggested for use in K.I.T.T.

    Utilising the concept of nutrients as a currency within organic farming system

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    This report was presented at the UK Organic Research 2002 Conference.Within organic systems, the successful management of nutrients at the field level is crucial for maximising production and minimising the environmental impacts. This requires that the farmer makes the best possible use of nutrients excreted by the grazing or housed livestock. In addition, the farmer must successfully manage the nutrients built-up in the ley phase of the crop rotation over the whole of the arable phase period. To analyse these complex flows, a nutrient budget model has been developed that describes the spatial and temporal flows within the organic farming system. The concept is analogous to treating nutrients as a currency where the flow of nutrients represents a cashflow. A spatial nutrient budget permits the analyses of the performance of the nutrient flows to be examined for the housing, manure, livestock, rotational land and permanent pasture to be analysed separately. This analysis will allow the farmer to better understand the weaknesses in the system, and hence take preventative measures

    Development of software to plan conversion to organic production (OrgPlan)

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    This report was presented at the UK Organic Research 2002 Conference. OrgPlan is a computer programme aimed at farmers and advisors assisting with the planning of an organic conversion. The programme is divided into technical modules, supported by a standard enterprise database, a report builder and an advisory section. Through the farm profile builder, rotation, cropping and livestock planner, conversion scenarios over several years can be developed and are evaluated for technical and financial feasibility by calculating farm gate budgets for key resources (forage energy and key nutrients) and financial reports (cash flow budget and profit and loss account). The poster illustrates the basic functioning of the software as well as the underlying rationale for the scenario evaluation

    Polarizing Impact: Indigenous Consultation Under International Labor Organization Convention 169 and the Emerging Polar Shipping Industry

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    This Article analyzes U.S. ratification of International Labour Organization (ILO) Convention 169, Indigenous and Tribal Peoples Convention (“Convention 169” or “C. 169”), by evaluating the impact in terms of its ability to solidify its protections of the land and lifeways of Arctic Indigenous people and strengthen the United States’s position as an international leader in Arctic life, development, and policy. Part I presents the issues. Part II introduces the growth of a polar shipping industry in the context of a rapidly melting Arctic. Part III provides a brief gloss on the complex and shifting international legal framework governing Arctic sovereignty and the Arctic Indigenous people, and then outlines, in detail, the consultation and participation norms of Articles 6 and 7 of Convention 169. Part IV evaluates Convention 169’s ability to protect and promote Arctic Indigenous rights to self-determination and its potential application in an ice- free Arctic shipping industry. Finally, Part V concludes that the United States should ratify Convention 169 and implement consultation under Articles 6 and 7 as an imperfect, yet worthwhile, modality for promoting the interests of Indigenous people in the rapidly growing polar shipping industry

    The neglect of northern England’s Neolithic and Early Bronze Age structures in the archaeological literature of Britain

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    For many years, it has been noted, from my own personal observations and from literature referring to the Neolithic and Early Bronze Age (N/EBA) structures in northern England, that there has been a neglect in referencing these sites. Nevertheless, there are numerous impressive monuments and landscapes in northern England. These include seventy Cumbrian stone circles, 1500 Bronze Age barrows in Yorkshire, amazing Northumbrian rock art, and henge and cursus complexes, as well as Neolithic round and long mounds in North Yorkshire. The earliest antiquarians were fascinated by southern Britain’s prehistoric structures. They have assumed that these monuments are the best and the most interesting examples or type-sites in Britain. Although northern sites have provided early dates and new archaeological material and information, many British archaeologists have not referenced these structures. In fact, even in books and articles about northern England’s prehistoric structures, the author(s) often provide comparisons of structures within southern Britain, rather than presenting their data in its own right or comparing it with another site elsewhere. While the Wessex and Orkney monuments are awe-inspiring, some of their sites have been under continual scrutiny, investigation and constant publication, with some archaeologists unable to see the magnificence beyond. Despite many references to this disparity, for example, Barclay (2001, 13) or Harding (2013, 1-2), the situation continues. In fact, this issue has been unresolved for forty years (Miket 1976, 113). This thesis was therefore undertaken to see whether this could or could not be proven, by analysing various syntheses from a national perspective. Books written about the Neolithic and Early Bronze Age, with Britain in the title, would be studied. The variety and complexity of northern England’s structures within their N/EBA landscapes will be discussed ideas will be offered for future research

    Numerical simulation of CO2 storage in saline aquifers

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    CO2 capture and storage (CCS) has been proposed as a climate change mitigation strategy. The basic principle is to prevent CO2 which would normally be emitted from large point sources, such as power stations, from entering the atmosphere. This is achieved by capturing the CO2 at source and storing it in a location where it will be trapped and unable to enter the atmosphere. This work looks specifically at geological storage of CO2 in deep saline formations. Dynamic simulations can be used to investigate the fundamental physical and chemical processes which occur when CO2 is injected into geological formations. They can also be used to determine the suitability of a particular site for CO2 storage. The scale of the processes being simulated is important when building a dynamic model. Here dynamic simulations have been used to explore three different aspects of geological CO2 storage in deep saline formations. The first model investigates large scale CO2 migration and pressure build up at a potential CCS site. The second model concentrates on the small scale processes of CO2 dissolution and convection. The third model attempts to accurately model both the large scale processes of CO2 injection and migration and the small scale processes of CO2 dissolution and convection. Dynamic simulations have been used to model storage capacity, CO2 migration and pressure buildup at a potential CO2 storage site in the UK North Sea. There are large uncertainties in the input data so various models have been run using a range of parameters. The primary control on pressure buildup at the site is the permeability of the unit directly beneath it. The plume diameter is primarily controlled by the porosity and permeability of the reservoir unit. Despite uncertainties in the input data, the use of a full three-dimensional (3D) numerical simulation has been extremely useful for identifying and prioritizing factors that need further investigation. Dissolution of CO2 into existing formation waters (brine) leads to an increase in brine density proportional to the amount of dissolved CO2. This can lead to gravitational instabilities and the formation of convection currents. Convection currents, in turn, will increase CO2 dissolution rates by removing CO2 saturated brine from the CO2-brine interface. The dissolution and subsequent convection of CO2 which has leaked through a fracture is investigated using dynamic simulations. The instigation of convection currents due to flow through a fracture increases dissolution rates. Comparison of our results with fracture flow rates shows that for typical fracture apertures dissolution from a fracture is small relative to the amount of CO2 flowing through the fracture. Two phase flow effects and the currents caused by an advancing plume of injected CO2 can affect patterns of CO2 dissolution and convection within a reservoir. Most existing models of CO2 dissolution and convection use a static boundary layer or do not involve two phase flow effects. A radial, two phase, two component model has been built to model the injection process along with convection enhanced dissolution. The model performs well compared to analytical solutions in terms of the large scale processes of CO2 migration and pressure buildup but modelled convection is highly dependent on grid resolution. Numerical instabilities are also present. Further work is needed to increase the accuracy of the model in order to allow higher resolution modelling to be carried out and modelling of the smaller scale processes to be improved
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