Conversion to Organic Field Vegetable Production (Phase 2)

Introduction, aims and objectives When this project began in 1996 the UK supply of organic vegetables, from 2400 hectares, was insufficient to meet the growing market and the majority of organic vegetables were imported. It was a policy objective to enable UK farmers to meet the demands of this growing market. A farmer converting to organic agriculture is faced with a range of specific agronomic and economic challenges different from those of conventional agriculture and of established organic systems and a lack of knowledge about these challenges was recognised as a major barrier for individual farmers considering conversion. The overall aim of this project was therefore to provide information on the agronomic and economic performance of farming systems which included field vegetables as part of their rotations during the conversion period and in the years immediately afterwards. The project was commissioned in 1996 as Project OF0126T, later continued as OF0191; this report describes the findings from both projects. The projects were led by HDRA with HRI (now Warwick HRI), EFRC (Elm Farm Research Centre), and the Institute of Rural Sciences (University of Wales, Aberystwyth) as subcontractors. The main objectives were: 1. To convert 12 ha (Hunts Mill) of the farm at HRI Wellesbourne to an organic system, with a rotation including field vegetables and arable crops. 2. To assess agronomic and economic performance of the crops grown, soils, weeds, pest and diseases, during conversion and for the first target rotation at Hunts Mill. 3. To assess the overall agronomic and financial performance during the first full cycle of the rotations at Hunts Mill, comparing scenarios where the initial fertility building phase was 29 months, 17 or 7 months. 4. To assess the agronomic and economic performance during conversion at 10 commercial reference farms, representing contrasting scenarios of organic vegetable production. 5. To interpret and evaluate the data and to produce information appropriate to aid farmers who are undergoing, or who are considering undergoing conversion to organic systems, and to aid future policy making on related farming issues. The reference farms were selected to represent three different scenarios of conversion (from conventional arable, from conventional intensive vegetable and from conventional mixed farms with livestock). The farms represented a range of sizes and were located in all the principle vegetable growing areas of England. The assessment period covered the two-year conversion period itself plus at least the first three years of certified organic production. The basic experimental approach was to use all the farms as case studies for monitoring and documenting the performance of the systems undergoing conversion. Comparisons were made between Hunts Mill and the reference farms and also between the reference farms representing the same vegetable production scenario and between the three different scenarios. See main document for a summary of findings. More specific key agronomic and economic findings can also be found in the main report. Conclusions The project has demonstrated that the process of conversion from conventional agriculture to organic vegetables production is often quite complex involving a significant number of innovations and restructuring of the farm systems, including changes in production, the introduction of new enterprises and marketing methods. These have resulted in a number of physical, financial and management changes both during the transition process and on the final organic farm businesses. The project has demonstrated that large-scale organic vegetable production is technically feasible, with soil fertility, weeds and pest and disease problems overcome without too much difficulty. The biggest challenges have been marketing, managing labour and making it financially viable at the farm level. Organic Farming Scheme payments have only made small contributions to the ‘cost of conversion’. Conversions, especially on the larger farms, would seem to be preferable over a 5 to 10 year period, allowing time to make the necessary learning and adjustments. Further research Monitoring at Hunts Mill has been extended until 2006 as part of a new project: Organic field vegetable production – baseline monitoring of systems with different fertility building strategies (OF 0332). Monitoring of some of the reference farms has continued as part of the project The Sustainable Vegetable Systems Network (OF 0340). This project monitors agronomy and economics and aims to assist in the development of established organic vegetable systems. Economic conditions change and the impact of the new CAP reforms beginning in 2005 would merit further research. The models developed within this project could form the basis for this work

The Control of Pupil Conduct by the School

The rapid exhaustion of the finite reserves of fossil-fuels adds to the woes on all walks of the society, and especially on the policy-makers, scientists and engineers to devise means to mitigate the consequences. Reducing energy demand and grid-dependency by decentralized energy production can help improve energy security of a nation. A holistic approach to achieve these goals in the building sector could be through a shift towards fostering near zero-energy communities. This project is an initiative taken by the residents in Van Maanenblok, an urban residential block constructed in early 1930’s and situated at the heart of North-Rotterdam, to try to achieve self-sustainability in terms of energy consumption of the block through renovation. The objective of this study is to analyze the energy consumption of the block over the past three years and using the ‘Trias Energetica’ approach, investigate the extent to which self-sustainability is possible. This study also includes an overview on financial feasibility of this initiative together with identification of innovation opportunities. Passive energy reduction measures such as insulation, LED lighting-retrofits have been explored. Active renewable energy systems (RES) like solar photovoltaic (PV) systems, micro-windmills were designed and sized. Also, energy potential from Organic Fraction of Municipal Solid Waste (OFMSW) from within the block, and use ground-source heat pump to meet thermal energy has been investigated. The aforementioned technologies have been compared over certain financial parameters like net present value (NPV), payback period (PBP), and levelised cost of energy (LCOE) based on installation costs obtained from actual figures quoted by the installers and also general indicative market figures. Results of the study indicate that nearly 54% of present gas demand and 9% of electricity demand can be reduced by passive energy reduction measures alone. It would be possible to meet 42% and 54% of reduced electricity and gas demand respectively from RES. User-behaviour plays an important role in energy consumption and social factor largely determines the metamorphosis of projects with such complex setup. Renovation projects towards near zero energy buildings opens up several innovative opportunities and extended benefits to various actors, however stimulus from government is needed on financial and technical front in order to realize such ambitious initiatives

The use of case studies in researching the conversion to organic farming systems

This poster reviews the use of case studies in studying farms converting to organic production. Particular reference is made to the 'Conversion to organic field vegetable production' project, which is making use of case studies. Case studies facilitate an in depth analysis of a farm during the conversion to organic production and enable researchers and farmers to gain a greater understanding of the complex changes that take place. Case studies also provide a valuable tool for disseminating the result

Chromosome breakpoint distribution of damage induced in peripheral blood lymphocytes by densely ionising radiation

Purpose: To assess the chromosomal breakpoint distribution in human peripheral blood lymphocytes (PBL) after exposure to a low dose of high linear energy transfer (LET) α-particles using the technique of multiplex fluorescence in situ hybridisation (m-FISH). Materials and methods: Separated PBL were exposed in G0 to 0.5 Gy 238 Pu α-particles, stimulated to divide and harvested ~48-50 hours after exposure. Metaphase cells were assayed by m-FISH and chromosome breaks identified. The observed distribution of breaks were then compared with expected distributions of breaks, calculated on the assumption that the distribution of breaks is random with regard to either chromosome volume or chromosome surface area. Results: More breaks than expected were observed on chromosomes 2 and 11, however no particular region of either chromosome was identified as significantly contributing to this over-representation. The identification of hot or cold chromosome regions (pter,p,cen,q,qter) varied depending on whether the data were compared according to chromosome volume or surface area. Conclusions: A deviation from randomness in chromosome breakpoint distribution was observed, and this was greatest when data were compared according to the relative surface area of each individual chromosome (or region). The identification of breaks by m-FISH (i.e. more efficient observation of interchanges than intrachanges) and importance of territorial boundaries on interchange formation are thought to contribute to these differences. The significance of the observed non-random distribution of breaks on chromosomes 2 and 11 in relation to chromatin organisation is unclear

Development of a polyclonal competitive enzyme-linked immunosorbent assay for detection of antibodies to Ehrlichia ruminantium

A polyclonal competitive enzyme-linked immunosorbent assay (PC-ELISA) is described for detection of antibodies to Ehrlichia (Cowdria) ruminantium by using a soluble extract of endothelial cell culture-derived E. ruminantium as the antigen and biotin-labeled polyclonal goat immunoglobulins as the competitor. For goats, the diagnostic sensitivity and specificity were both 100% with a cutoff of 80% inhibition (80 PI), with detection of antibodies for 550 days postinfection. For cattle, diagnostic sensitivity and specificity were 86 and 100%, respectively, with a cutoff of 50 PI and 79 and 100% with a cutoff of 70 PI. Cross-reactions with high-titer experimental or field antisera to other Ehrlichia and Anaplasma species were observed at up to 68 PI in cattle and up to 85 PI in sheep, and therefore to exclude these cross-reactions, cutoffs of 70 PI for bovine serology and 85 PI for small-ruminant serology were selected. Application of the PC-ELISA to bovine field sera from South Africa gave a higher proportion of positive results than application of the murine macrophage immunofluorescent antibody test or indirect ELISA, suggesting a better sensitivity for detection of recovered cattle, and results with bovine field sera from Malawi were consistent with the observed endemic state of heartwater and the level of tick control practiced at the sample sites. Reproducibility was high, with average standard deviations intraplate of 1.2 PI and interplate of 0.6 PI. The test format is simple, and the test is economical to perform and has a level of sensitivity for detection of low-titer positive bovine sera that may prove to be of value in epidemiological studies on heartwater

Increases in the Irreversibility Field and the Upper Critical Field of Bulk MgB2 by ZrB2 Addition

In a study of the influence of ZrB2 additions on the irreversibility field, Birr and the upper critical field Bc2, bulk samples with 7.5 at. % ZrB2 additions were made by a powder milling and compaction technique. These samples were then heated to 700-900C for 0.5 hours. Resistive transitions were measured at 4.2 K and Birr and Bc2 values were determined. An increase in Bc2 from 20.5 T to 28.6 T and enhancement of Birr from 16 T to 24 T were observed in the ZrB2 doped sample as compared to the binary sample at 4.2 K. Critical field increases similar to those found with SiC doping were seen at 4.2 K. At higher temperatures, increases in Birr were also determined by M-H loop extrapolation and closure. Values of Birr which were enhanced with ZrB2 doping (as compared to the binary) were seen at temperatures up to 34 K, with Birr values larger than those for SiC doped samples at higher temperatures. The transition temperature, Tc, was then measured using DC susceptibility and a 2.5 K drop of the midpoint of Tc was observed. The critical current density was determined using magnetic measurements and was found to increase at all temperatures between 4.2 K and 35 K with ZrB2 doping.Comment: 15 pages, 5 figs, 1 tabl