Soil organic carbon and root distribution in a temperate arable agroforestry system

Aim To determine, for arable land in a temperate area, the effect of tree establishment and intercropping treatments, on the distribution of roots and soil organic carbon to a depth of 1.5 m. Methods A poplar (Populus sp.) silvoarable agroforestry experiment including arable controls was established on arable land in lowland England in 1992. The trees were intercropped with an arable rotation or bare fallow for the first 11 years, thereafter grass was allowed to establish. Coarse and fine root distributions (to depths of up to 1.5 m and up to 5 m from the trees) were measured in 1996, 2003, and 2011. The amount and type of soil carbon to 1.5 m depth was also measured in 2011. Results The trees, initially surrounded by arable crops rather than fallow, had a deeper coarse root distribution with less lateral expansion. In 2011, the combined length of tree and understorey vegetation roots was greater in the agroforestry treatments than the control, at depths below 0.9 m. Between 0 and 1.5 m depth, the fine root carbon in the agroforestry treatment (2.56 t ha-1) was 79% greater than that in the control (1.43 t ha-1). Although the soil organic carbon in the top 0.6 m under the trees (161 t C ha-1) was greater than in the control (142 t C ha-1), a tendency for smaller soil carbon levels beneath the trees at lower depths, meant that there was no overall tree effect when a 1.5 m soil depth was considered. From a limited sample, there was no tree effect on the proportion of recalcitrant soil organic carbon. Conclusions The observed decline in soil carbon beneath the trees at soil depths greater than 60 cm, if observed elsewhere, has important implication for assessments of the role of afforestation and agroforestry in sequestering carbon

The electrocardiogram in the eucalcemic, hypercalcemic and hypocalcemic animal

Call number: LD2668 .T4 1962 U6

Economic Potential of Using High Tunnel Hoop Houses to Produce Fruits and Vegetables

Abstract Hoop house plasticulture has been promoted as a production technology that allows fruit and vegetable crops to be grown in the cool season months in early spring and late fall. At this time little information regarding the economics of hoop house plasticulture is available. Two fruit and vegetable production systems were developed for growing conditions in south-central Oklahoma. The first system has a spinach crop followed by field tomato, and the second system has annually produced strawberry followed by yellow and zucchini squash. Crop production data were collected in a three-year randomized and replicated experiment. The objectives were (1) to determine the expected cost of production for each crop and systems, (2) to determine the breakeven price for each crop in each system, and (3) to determine how robust breakeven prices are to a number of yield, expense and marketing scenarios. The expected total cost of production were $1,968 and$1,652 per house for spinach and tomato crops, respectively, and $2,749,$359 and $353 per house for yellow and zucchini squash crops, respectively. Breakeven prices for spinach and tomato were$3.32 and $0.83 per pound, respectively, and$6.16, $0.92, and$1.40 per pound for strawberry and yellow and zucchini squash, respectively. Breakeven prices for spinach and strawberry crops were most sensitive to assumptions about quantity of marketable yield sold and/or quantity of yield consumed by grower household.breakeven prices, economics, fruits and vegetables, hoop houses, plasticulture, Agribusiness, Farm Management, Labor and Human Capital, Marketing, Production Economics,

Economic Feasibility of Small Scale Vegetable Production and Retailing in Rural Communities

Economic information about the feasibility of producing and retailing vegetables in rural communities is limited. The objectives were to determine actual net return from producing and retailing a mix of produce in a rural community, and to determine if consumers were willing to pay differentiated prices for the locally-grown vegetables.Crop Production/Industries,

Mathematical Modelling of Chemical Diffusion through Skin using Grid-based PSEs

A Problem Solving Environment (PSE) with connections to remote distributed Grid processes is developed. The Grid simulation is itself a parallel process and allows steering of individual or multiple runs of the core computation of chemical diffusion through the stratum corneum, the outer layer of the skin. The effectiveness of this Grid-based approach in improving the quality of the simulation is assessed

Widespread association between the ericoid mycorrhizal fungus Rhizoscyphus ericae and a leafy liverwort in the maritime and sub-Antarctic

A recent study identified a fungal isolate from the Antarctic leafy liverwort Cephaloziella varians as the ericoid mycorrhizal associate Rhizoscyphus ericae. However, nothing is known about the wider Antarctic distribution of R. ericae in C. varians, and inoculation experiments confirming the ability of the fungus to form coils in the liverwort are lacking. Using direct isolation and baiting with Vaccinium macrocarpon seedlings, fungi were isolated from C. varians sampled from eight sites across a 1875-km transect through sub- and maritime Antarctica. The ability of an isolate to form coils in aseptically grown C. varians was also tested. Fungi with 98–99% sequence identity to R. ericae internal transcribed spacer (ITS) region and partial large subunit ribosomal (r)DNA sequences were frequently isolated from C. varians at all sites sampled. The EF4/Fung5 primer set did not amplify small subunit rDNA from three of five R. ericae isolates, probably accounting for the reported absence of the fungus from C. varians in a previous study. Rhizoscyphus ericae was found to colonize aseptically-grown C. varians intracellularly, forming hyphal coils. This study shows that the association between R. ericae and C. varians is apparently widespread in Antarctica, and confirms that R. ericae is at least in part responsible for the formation of the coils observed in rhizoids of field-collected C. varians

Centrifugally Spun PHBV Micro and Nanofibres

This paper reports the first study on centrifugal spinning of PHBV fibres. Fibres were spun from solution using a range of polymer concentrations, spin speeds and spinneret to collector distances. A PHBV polymer concentration of 25% w/v spun at 9000 r min⁻¹ produced the highest quality fibres, with fibre diameters predominantly in the 0.5-3 μm range. The rate at which fibre could be produced at the 9000 r min‾¹ spin speed and with a spinneret to collector distance of 39.2 cm was equivalent to 11 km of fibre per minute per needle. Average fibre strengths of 3 MPa were achieved, together with average moduli of 100 MPa, indicating that the fibres had higher strength but lower stiffness than electrospun PHBV. The productivity and mechanical properties achieved, together with the excellent biocompatibility of PHBV, means that these fibres have potential for application in a range of biomedical applications

Using EcoYieldSAFE to compare soil carbon dynamics under future climate in two contrasting agroforestry systems

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Analysing and improving methods of horse and rider safety on roads through campaigns and design experiences

There continues to be a rise in the number of incidents involving horse and rider on the UK roads, sparking an increase in attempts to educate the UK’s car driving public to the presence of horses. Through the analysis and study of different road users andh ow they use the roads individually, campaigns can be created that are tailored to their needs and experiences on the roads. In this study I combine behavioural theories and horse physiology, to explain factors that increase risk to horse and rider safety using the research-through-design approach. The work created seeks to support those in the event of a dangerous situation, allowing them to be prepared and to provide preventative techniques. The research also creates a foundation for further campaigns to be created that can be tailored to raise awareness about key problem areas and target specific audiences such as car drivers, lorry drivers and cyclists. By using semi-structured interviews, local police reports and horse and rider safety events, Iam able to assess current campaigns; and the design decisions behind their communications,thus opening them up for further analysis and future development. Drawing from this analysis, I concluded that a new campaign needed to be created to develop and bridge the gaps in the education of the general public in relation to horses and their safety on the roads

The coming of age of EvoMPMI:evolutionary molecular plant-microbe interactions across multiple timescales

Plant-microbe interactions are great model systems to study co-evolutionary dynamics across multiple timescales. However, mechanistic research on plant-microbe interactions has often been conducted with little consideration of evolutionary concepts and methods. Conversely, evolutionary research has rarely integrated the range of mechanisms and models from the molecular plant-microbe interactions field. In recent years, the incipient field of evolutionary molecular plant-microbe interactions (EvoMPMI) has emerged to bridge this gap. Here, we report on some of the recent advances in EvoMPMI. In particular, we highlight new systems to study microbe interactions with early diverging land plants, and new findings from studies of adaptive evolution in pathogens and plants. By linking mechanistic and evolutionary research, EvoMPMI promises to expand our understanding of plant-microbe interactions