3,424,227 research outputs found

    Sustainable production systems for organic apple production

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    Organic apples are often sold for fresh consumption and therefore have to obtain high quality requirements. The fruits must obtain the right size and be undamaged without important infections of pest and diseases. Apple scab causes brown or black spots on the fruits and severe infections can result in fruits not suitable for consumption. This disease causes big reduction in yield and quality in organic production. Copper is an effective fungicide to control diseases and is used in organic apple production in some European countries. Copper has not been permitted in Denmark the last 10 years and the European Union wants to reject it from the list of pesticides permitted in organic production. To improve the quality and yield in organic apple production, it is important to find the best culture techniques. Combinations of cultivars, nitrogen availability, rootstocks and planting distances are tried to prevent or reduce apple scab infections

    Optimising production systems for organic pig production (OF0169)

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    This is the final report of Defra project OF0169. There is a more comprehensive Executive Summary at the start of the attached main report. The overall objective of this project was to generate the scientific and financial information necessary to facilitate increased production of pigmeat on existing organic farms, and the conversion of conventional farms to this organic production. Information was collected through a series of experiments focusing on the effects of genotype, management and nutrition. The study was conducted on commercial organic pig farms, supported by literature searches, financial appraisal, and survey data collection. Organic production standards favour traditional breeds of livestock in preference to ‘improved’ genotypes, which may be less suited to the more extensive production systems. An experiment was carried out to compare performance, health and welfare of three different genotypes managed organically. These genotypes were chosen to represent different breeding strategies - British Saddleback (S), a pure-bred, traditional genotype; PIC Camborough 12 (C12), an improved modern genotype; and Saddleback x Duroc (SD) sow, suitable for ‘criss-cross breeding’ system by smaller organic farms. The modern improved genotypes of sows produced higher litter sizes than their more traditional counterparts, although the numbers of pigs weaned were similar across the genotypes studied. The results indicated that all three breeding strategies can be successfully adopted in organic production systems, and that choice of sow breed should depend on the ability of the farm to manage prolific sows, the implications for slaughter pig performance, and market requirements. A factorially designed experiment was carried out to investigate the effects on performance and carcass quality of three different genotypes of growing pig, three feeding systems and two housing systems. Overall, there were few significant treatment effects on product quality. In a further experiment, the herbage intake of growing pigs maintained at pasture was quantified. The results showed that, when offered a cereal- based concentrate ad libitum, the herbage intake of growing pigs from a good quality grass/clover sward contributed <5% to daily organic matter consumption. In these circumstances, modification of concentrate composition would not be appropriate. To facilitate efficient feed use in organic pig production, a ‘Feed Handbook’ (publication C3) was compiled, printed and made available to UK organic farmers. The effect of paddock management on the ranging behaviour of sows was also studied in a two by three factorial design, involving three sow genotypes. Two commercially applicable paddock management strategies were established: a) ‘Rotational’ (R) where a group of up to 6 sows was relocated to clean ground every four months, and b) ‘Set stocked’ (SS) where a group of up to 6 sows was relocated to clean ground every twelve months. Results suggest that during wet periods, the R paddocks may be advantageous as the pigs are moved off damaged pasture, whereas in drier periods, the SS paddocks maintain grass cover for longer than R and therefore incur less labour for moving without significant pollution risk. Pigs in the SS paddocks do use the further portions of the field, but this may require management manipulations to achieve satisfactory grass usage and distribution of excreted nutrients. In a survey conducted between August 1999 and April 2002 on the commercial organic farms, the main welfare issues reported related to keeping stock clean and dry in periods of high rainfall, managing Porcine Dermatitis and Nephropathy Syndrome and Postweaning Multisystemic Wasting Syndrome (PDNS/PMWS) within their herd, and recruiting and retaining good quality personnel. Mange and lice were the highest-ranking current health concerns, and post-mortem reports of endo-parasitism was the highest-ranking historical health concern. Two of the five farms surveyed reported problems with scouring in young pigs probably due to Coccidia, which may pose a significant risk in organic systems. Data collected on physical performance, capital investment and operating costs were used to establish bench-mark production levels for organic pig herds, the cashflow implications of establishing an organic pig herd, profitability, and sensitivity to movements in productivity, costs and prices. This showed the potential for profitability, which was vulnerable to price fluctuations. Information was disseminated widely through farmer conferences and talks at national conferences, scientific papers, conference proceedings, technical and press reports

    Modelling Organic Dairy Production Systems

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    In this study, a large number of organic dairy production strategies were compared in terms of physical and financial performance through the integrated use of computer simulation models and organic case study farm data. Production and financial data from three organic case study farms were used as a basis for the modelling process to ensure that the modelled systems were based on real sets of resources that might be available to a farmer. The case study farms were selected to represent a range of farming systems in terms of farm size, concentrate use and location. This paper describes the process used to model the farm systems: the integration of the three models used and the use of indicators to assess the modelled farm systems in terms of physical sustainability and financial performance

    ALTERNATIVE COTTON PRODUCTION SYSTEMS

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    Mississippi cotton farmers are adjusting to the current problem of low cotton price and high cotton production cost by modifying the way(s) they have traditionally grown cotton. This paper compares seven alternative production systems to the costs and returns associated with the conventional or traditional system labeled "solid cotton, 8-row equipment." Systems that combine wider equipment (less labor and machinery time per acre) with reduced tillage technology appear to offer opportunities to increase returns. Specific adjustments on individual farms will probably be dominated by the distribution of soil types.conservation tillage, ultra-narrow, no-till, skip-row, costs, returns, Production Economics,

    Hadron production in heavy relativistic systems

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    We investigate particle production in heavy-ion collisions at RHIC energies as function of incident energy, and centrality in a three-sources Relativistic Diffusion Model. Pseudorapidity distributions of produced charged hadrons in Au + Au and Cu + Cu collisions at sqrt(s_NN) = 19.6 GeV, 62.4 GeV, 130 GeV and 200 GeV show an almost equilibrated midrapidity source that tends to increase in size towards higher incident energy, and more central collisions. It may indicate quark-gluon plasma formation prior to hadronization.Comment: 8 pages, 3 figure

    Entanglement production in Quantized Chaotic Systems

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    Quantum chaos is a subject whose major goal is to identify and to investigate different quantum signatures of classical chaos. Here we study entanglement production in coupled chaotic systems as a possible quantum indicator of classical chaos. We use coupled kicked tops as a model for our extensive numerical studies. We find that, in general, presence of chaos in the system produces more entanglement. However, coupling strength between two subsystems is also very important parameter for the entanglement production. Here we show how chaos can lead to large entanglement which is universal and describable by random matrix theory (RMT). We also explain entanglement production in coupled strongly chaotic systems by deriving a formula based on RMT. This formula is valid for arbitrary coupling strengths, as well as for sufficiently long time. Here we investigate also the effect of chaos on the entanglement production for the mixed initial state. We find that many properties of the mixed state entanglement production are qualitatively similar to the pure state entanglement production. We however still lack an analytical understanding of the mixed state entanglement production in chaotic systems.Comment: 16 pages, 5 figures. To appear in Pramana:Journal of Physic
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