PhD, EngD, DM and MSc by research theses (Silsoe)

Permanent URI for this collection

https://dspace.lib.cranfield.ac.uk/handle/1826/7

Browse

Now showing 1 - 20 of 279

Open Access
Paulownia agroforestry in China - a contribution to adaptive research.
(Cranfield University, 1996-10) Wu, Yunying; Morgan, R. P. C.
Nearly 2 million hectares of farmland have been intercropped with rows of paulownia (Paulownia elongata) trees in the North Central Plain of China. Paulownia provides an important timber source and long term income as a "saving bank". It is in harmony both ecologically and economically with the understorey winter wheat (Triticum spp.), the farmers' "survival food". Funded by ODA (Overseas Development Administration, UK), the present study investigates the role of the paulownia-crop intercropping (PCI) system in rural socio-economic development. It also identifies the socio-economic and technical factors that affect the promotion and success of PCI and examines the needs and problems encountered in the development of PCI under the present "Individual Responsibility System" (IRS). A socio-economic survey on PCI in Chengwu, Shandong Province, as a case study, shows that paulownia intercropping is an important component of socio-economic development in the poor areas. Existing policy on paulownia intercropping and land distribution causes some problems for farmers, and technical guidance on optimum tree spacing, management and maximum production of PCI with emphasis on wheat yield is eagerly awaited. An adaptive research approach to address the farmers' needs was applied in this study by interpreting scientific research to produce a useful, simple and practical model to optimise tree spacing for a range of scenarios. Data used for analysis were collected during 1983 - 1992 from an experiment station at Dangshan, Anhui Province, on a project supported by The International Development Research Centre (IDRC) of Canada. The important components of the PCI system including tree growth, growth and yield of understorey crops, and light, as a key microclimate factor affecting understorey crops, were analysed to further understanding on the natural functioning of the PCI system. The denser the spacing, the earlier the fast-growth stage of the trees occurs. However, there was no significant difference among the spacings in any of the growth variables at the end of the study in the 10th intercropping year. There are always reductions in light transmissivity (LT) and Photosynthesis Active Radiation (PAR) and the proportion of PAR to total solar radiation in the intercropped fields due to light interception by the trees. These effects are more apparent in areas near the trees, in denser spacings, in older paulownia, and when the paulownia have fully developed leaves. Intercropped wheat benefits from the modified microclimate, such as reduced temperature and increased soil water contents and relative humidity. Air temperature is the only microclimatic factor determining wheat leaf conductance, which gives a negative effect. Wheat yields start to decrease when LT is reduced to 81.8% as an average and about 10% higher for dense spacing and older trees and 10% lower for larger spacing and younger trees. Leaf conductance, biomass and yield of the intercropped wheat are slightly above those in open fields when the trees are young and widely spaced, but lower otherwise. The distribution of wheat yield across the alley in the intercropped field was similar to that of light, apart from in the dense spacing of older age trees where the competition of tree roots for nutrients probably also reduces yields near the tree rows. The reduction of leaf conductance and yield of summer crops by paulownia is greater than for the winter crop due to shading by the trees and different response of the crops. The yield reduction of cotton and maize is 15% at the edge of the tree canopy and as much as 50% near the tree rows. Regression models were developed to express DBH (used as an index of tree growth) as a function of age; light transmissivity as a function of distance across the alley for different spacings and ages of trees; understorey wheat yield as a function of distance across the alley for different spacings and ages of trees; and understorey wheat yield as a function of light transmissivity. The models can yield information on rates of tree growth and changes in understorey wheat yield and LT, by inputting tree age, and distance from west row under a given tree spacing. The output will help farmers optimise the tree-row spacing depending on whether their objective is to maximise timber production, crop production or the economic return from both. The models could also provide useful and practical technical guidance to help decision-making and settle disputes among farmers and between farmers and the local authority. Models were validated by the data collected during 1993 - 1994 from farmers' fields in Chengwu, Shandong Province. All the models perform well in these conditions and it is recommended that they be applied to PCI in all parts of North Central Plain of China due to the similarity of climate and soil conditions. Optimum tree spacings under different scenarios were also recommended. The present study demonstrated the approach of adaptive research in PCI agroforestry by linking scientific findings to rural socio-economics and farmers' needs. It indicated the equal importance of three components: socio-economic survey, experimental data analysis and interpretation, and application of scientific findings. Socio-economic survey at the village or farm level is essential for identifying the needs of farmers from PCI under IRS conditions. Data analysis helps scientists and extension officers to understand and interpret the dynamic eco-biological interactions of PCI systems . Regression modelling is a practical, efficient, simple and easy way of interpreting and applying scientific findings to a realistic PCI system.
Open Access
Assessment of crop performance potential using remote sensing
(1992) Zmuda, A. D.; Taylor, J. C.
This report demonstrates the potential use of optical remote sensing for monitoring the growth and development of winter sown wheat at the field scale. Spectral vegetation indices have been shown to be correlated to important agronomic variables i.e. Leaf Area Index, per cent cover, intercepted solar radiation and grain yield. For winter sown cereals, relationships to grain yield at harvest have been proposed at various times during the growth of the crop. However the precise timing of the remotely sensed input to such models has not received investigation in relation to sowing date, variety and development stage. Further the effect of fungal diseases on such models is not well understood. To address these problems, commercial agronomy trials were used to monitor the reflectance patterns of winter wheat over two growing seasons. During growth and development of the crop, the wheat was destructively sampled and the apex development stage was recorded. Key stages of apex development were found in which spectral data was correlated to grain yield. The relationships were found to be complex in relation to sowing date, variety and fungicide treatment and may therefore not be applicable on a year to year basis.
Open Access
Application of GIS and remote sensing for land use planning in the arid areas of Jordan
(2000-01) Ziadat, Feras M.; Taylor, J. C.
Land suitability analysis formed part of a land use planning exercise in a development project aimed at improving agricultural productivity in the transitional Badia region of Jordan. Soil observations and soil maps were available at three levels of detail with differing coverage: level one (1:250,000 scale -complete cover), level two (1:50,000 scale - part cover) and level three (1:10,000 scale very limited cover). The development project selected the FAO Framework for Land Evaluation as the basis for land suitability analysis. This research investigated seven different calculation approaches for the processing of soil observations within soil map polygons using a GIS to derive land suitability ratings. These methods either use the soil observations to calculate the suitability of each soil mapping polygon or an interpolation technique (Voronoi diagram or Triangulated Irregular Network) between observation points. The overall map purity and homogeneity with respect to land characteristics were used to evaluate these methods. The quality of suitability maps varied according to the level of soil mapping and the method of processing the soil observations. The relative performance of the processing methods is discussed and recommendations for each level of mapping are proposed. The results showed that the purity of suitability maps was between 60 and 70% at the highest level of detail. Thus they should be used with caution for site specific analyses. Statements of map quality should be appended to suitability maps. The soil maps and observation points were derived and collected in a previous soil survey programme and georeferenced by map reading before the widespread availability of the Global Positioning System (GPS). When the data were integrated and overlaid on a satellite image within a GIS, a number of inconsistencies in georeferencing the data and in the attributes attached to them were revealed. Investigation and correction of these evolved into a major component of this work. Systematic errors caused by the use of different datums to georeference soil maps and observation points in the Jordan Soil and Climate Information System (JOSCIS) were detected. The map reading procedure also caused unsystematic errors in the locations of soil observations, which were re-measured at a sample of original observation sites using GPS. The correction of the unsystematic errors was not feasible due to the difficulty and cost of relocating all observation points. Errors in the attributes attached to the observation points were caused by survey recording procedures, highlighting the need for an examination of the data before analysis. The systematic and attribute errors were corrected and the implication for suitability analysis examined. The areas and spatial distribution of different suitability classes were affected increasingly as the level of mapping became more detailed. The presence of all these errors was sufficient to create errors in the derived land suitability maps, which could lead to incorrect land use planning decisions. The integration of satellite imagery, soil observations and soil mapping polygons within a GIS was indispensable for quality control of the data. The highest purities of suitability maps using existing soil mapping polygons were between 60% to 70% at level three but they only covered veiy limited areas. This indicated the need to extend mapping at this detail for site-specific planning and if possible, to increase the purity of soil mapping units. This was investigated by integrating satellite imagery and topographic data in a GIS. A 3-D perspective view of a Landsat TM image using an air photo-derived DEM was the most promising way of using the available data. Further research is needed to investigate the interactive use of air photo-derived DEMs and Landsat images, with more focus applied to site specific planning and field verification of the technique. Although this work was necessarily focussed on the issues and problems particular to one data set used in a Jordanian context, a number of general lessons have been learned. Firstly, careful examination of all input data is necessary to eliminate georeferencing and attribute errors. Secondly, overlay of input data onto a geocoded satellite image is extremely useful for detecting potential sources of input data errors and is recommended. And thirdly, GIS is indispensable for investigating existing data for errors and exploring new methods of analysis.
Open Access
Natural disease resistance in strawberry fruit and Geraldton waxflower flowers
(2002) Terry, Leon Alexander; Joyce, Daryl C.
Antifungal activity against Botrytis cinerea and Cladosporium cladosporioides declined with increasing fruit maturity as shown by thin layer chromatography (TLC) bioassay. Preformed antifungal activity was also demonstrated in flower tissue. Decline in fruit antifungal compounds was correlated with a decline in natural disease resistance (NDR) against B. cinerea. Crude extracts of green stage I fruit contained at least two previously unreported preformed antifungal compounds (Rf = 0.44 and 0.37) that were not present in white and red stage fruit. These compounds were confirmed by TLC reagent sprays not to be phenolics or alkaloids. Positive reactions to Ehrlich’s reagent suggested that Rf = 0.37 was a teipene. The majority of antifungal activity was found in the achenes of green stage I fruit. However, antifungal activity was found in all tissue types (viz. pith, cortex, epidermis) of green stage I fruit. TLC bioassays showed that all fruit stages showed antifungal activity at the origin (Rf = 0.00). The approximate area of fungal inhibition at origin in green stage 1 fruit extracts was 90 and 70% greater than in white and red stages. TLC reagent sprays confirmed that antifungal compounds at origin contain phenolics. This is consistent with previously reported phenolic compounds in strawberry fruit that are inhibitory to B. cinerea. An investigation into the potential of enhancing NDR using different chemical (acibenzolar), biological (Aureobasidium pullulons) and physical (UV-C) elicitors was conducted with a view to developing an integrated pest management (EPM) strategy. The most promising results were achieved with pre-harvest treatments of the chemical plant activator acibenzolar. Seven glasshouse trials were conducted over a three year period. Preharvest application of acibenzolar (0.25 - 2.0 mg AI ml'1) were effective in suppressing grey mould on strawberry fruit harvested from winter grown plants. Conversely, acibenzolar was ineffective at suppressing grey mould on fruit harvested from summer grown plants. However, where acibenzolar was effective, disease development was delayed by as much as 2 days. This delay was equivalent to a 15-20% increase in shelf-life. If systemic acquired resistance and/or other inducible mechanisms are to be implemented as part of an IPM strategy for controlling B. cinerea more research is required on how environment and management factors affect the efficacy of elicitors such as acibenzolar. Geraldton waxflower is the most economically important native Australian cut flower export. Infection of Geraldton waxflower by B. cinerea can lead to unacceptable levels of flower abscission after harvest. Thus, an investigation was conducted into the nature and identities of constitutive antifungal compounds in imported Geraldton waxflower flower and leaf tissues. Antifungal activity against B. cinerea and C. cladosporioides was observed in both Geraldton waxflower leaf and flower tissue. Leaf tissue contained considerably less antifungal activity than flower tissue. Some antifungal compounds were common to the three different waxflower cultivars studied. Through TLC reagent sprays and NMR GC-MS spectra, these antifungal compounds were identified as the sesquiterpenes, globulol and grandinol. There were also at least two unidentified phenolics. Notwithstanding similarities in antifungal profiles, it was also evident from TLC bioassays that significant variations exist between different waxflower cultivars. Further work is required to fully characterise the preformed antifungals compounds found in strawberry and Gerladton waxflower tissues and to elucidate pathways involved in their biosynthesis. In addition, work is also required to look at the full spectrum of antifungal activity of these antifungal compounds. Such information will allow precise definition of the roles that these compounds may play in suppression of in strawberry and waxflower NDR against B. cinerea. In turn, this knowledge should enable the introduction of improved and/or novel IPM strategies that enhance levels of these compounds.
Open Access
Use of sap flow measuring techniques to estimate water-use of multi-stem plants
(2006-01-19) Seymour, Ian Leslie; Burgess, Paul J.
In the UK, coppice willow is a potentially high yielding energy crop which if widely planted could have significant effects of hydrology. This is one reason why researchers are interested in developing reliable techniques for estimating whole-plant water use of such trees. In recent years various sap flow measuring techniques have become commercially available. The aim of this thesis was to evaluate the reliability sap flow measurement and to consider issues related to best practice when used on multi-stemmed woody plants. The thesis starts by reviewing methodologies for estimating tree water-use with particular focus on sap flow gauges. Subsequently over three years, experiments were undertaken using a commercially available Stem Heat Balance (SHB) sap flow gauges, manufactured by Dynamax Inc, Houston, Texas, on coppice willow grown in lysimeters. Plant responses were monitored through a range of soil-water conditions from flood to drought. Over three years a methodology for deriving an accurate assessment of total plant water-use using a lysimeter water balance (LWB) was developed. Whole-plant water-use, estimated from scaled up sap flow measurements from individual stems were compared against LWB values. Both, stem basal area and leaf area were used as scalars to derive values of plant water-use. In the final experiment, four out of eight, different sized sap flow gauges, with the appropriate scalar, gave estimates similar (±7%) to LWB values of whole-plant water use over a period of ‘unstressed’ growing conditions. Variation in the accuracy of estimates was considered to be a function of a) error inherent to the SHB technique, b) error in scalar values used to derive whole-plant estimates, and c) apparently autonomous responses of individual stems to changes in soil water status. In non-water stressed conditions and where sap flow rates are high, errors from the technique were minimised by selecting Targe’ stems (16-19 mm diameter). Under extreme water stress conditions, reductions in leaf area can result in errors if the estimate is based on stem diameter. Where individual stem flow rates were perturbed by changes in soil-water conditions, selecting an ‘intermediate’ sized stem (in this case 10-13 mm diameter) appeared to minimise errors.
Open Access
Continuous mass flow measurement of granular materials
(1997-10) Saunders, Stuart P.; Godwin, R. J.
This thesis reports on the development of a double inclined plane (DIP) transducer system based upon the principles of force reaction. This transducer had a design specification to measure the true mass of “free” flowing granular materials, primarily agricultural crops, with an accuracy of ± 2 % on total mass flowed for flow rates between 1 and 10 kg/s. Two absolute values are used to assess accuracy in this study, (i) the total mass flowed (kg), a measure of the mass accumulation and, (ii) the mass flow rate (kg/s), a ‘spot’ reading of flow rate. The performance of the novel system has been evaluated through theoretical, laboratory and field studies and consideration has been given to the commercial and business aspects of the manufacture, marketing and further development of the device. Following mathematical and laboratory studies of the sponsors current force reaction transducer - a single reaction device, angular variations were highlighted as having a significant effect upon output. A further study found that the least sensitive reaction plate angle was 55° To overcome this problem, the double inclined plane (DIP) concept was developed, 2 single reaction plates, joined along their apexes, angled at 55 degrees to the horizontal, mounted upon a horizontal strain gauged beam. Angular compensation when tilting the transducer was provided by generating a higher force from the shallower face and a lower force from the steeper face. A mathematical model of the new transducer allowed the output to be predicted to within 1.7 %. Initial calibration was undertaken in the laboratory and tested using a combine clean grain system simulation apparatus. In-situ machine studies were performed by mounting the transducer in a New Holland TF42 combine, firstly on an extended bubble up auger and finally in the drop box, between the clean grain elevator and bubble up auger. Initial pilot studies were conducted with the combine static to calibrate the system and finally a full harvest field trial was undertaken. Over the harvest field trial, the accuracy on accumulated mass was better than 0.9 % over 127 tonnes. Tramline effects upon transducer output were found to be self cancelling, as the resulting positive and negative ‘spikes’ in the signal, when summed over time approximated to zero. Changes in pitch angle, up to 10 degree caused between 1.5 and -2.8 % randomly distributed error. Roll angles up to 7.5 degrees, caused between -0.9 % and 1.7 % randomly distributed error in static trials. Field beans and oilseed rape required calibration constants 6.8 % and 3.1 % lower than that for 12.5 % moisture content wheat, but with adjusted calibration constants, gave excellent repeatable results. Increasing moisture contents of up to 30 % in wheat resulted in the transducer under reading by, on average, 1.6 %. An assessment of manufacturing costs was made and the unit cost was £154.12 each for 30 units reducing to £109.59 each for 3000 units. It is recommended a pricing objective of maximising sales growth is used which will position the device at the less expensive end of the market. Due to commercial sensitivity, a draft patent has been written to protect the DIP concept. The first stages of commercial adoption already being undertaken by a major multi-national agricultural machinery company, who are evaluating a pre-production prototype. This thesis provides the systems, data and principles required to create a novel, commercially practical transducer system, based upon the principles of force reaction. The problem of angular compensation has been overcome in a simple and effective manner offering a relatively inexpensive but accurate method of measuring mass flow rate, which has already received commercial interest.
Open Access
Optimising the performance of shallow, high-speed mouldboard ploughs
(2002-04-02) Saunders, Christopher; Godwin, R. J.
The aim of the project was to undertake experimental and theoretical research, to enable a better understanding of the design of modem mouldboard ploughs. Using this knowledge to optimise the performance in terms of width, depth and speed of operation to enable a more efficient cost saving operation. This would strengthen the presence of the mouldboard plough in the modem primary tillage machinery line-up and make it more competitive against other tillage systems. Soil bin and field studies were undertaken to determine the effect of operating depth, width and speed on the forces and movement of the soil. This was to determine if manufactures, especially Kvemeland; had followed the suggestions of previous researchers with the design of their number 8 mouldboard or an improvement in design was needed to enable high-speed operation. Not only was the design found to operate well at over a range of speed up to 10km/h but also provided good inversion at width/depth ratios up to 4:1. The experiments showed that depth had the greatest effect on the horizontal forces, followed by the width. Speed had the least affect on the draught force with only a 7.0% increase when increasing from 4.5 km/h to 10 km/h. This is very significant in improving the operation of and cost saving associated with high-speed plough operations. These studies indicated two critical issues that face manufactures i) The difficulty of increasing the furrow bottom width to accept wider tractor tyres. This problem was tackled with a re-design of the mouldboard assembly and further testing proved successful. The experiments showed that the actual furrow bottom width produced by the mouldboard could be increased for no additional increase in the horizontal force, both under controlled soil bin and field conditions. ii) The ability of the skimmer to operate at increased ploughing speeds. This problem was addressed by conducting soil bin and field studies on the standard manure skimmer. The forces were measured for a range of depths, speeds, rake angles and approach angles allowing an understanding of how pitch and yaw of the skimmer body affect the forces and the soil flow. The horizontal force studies were conducted under soil bin conditions and showed that both a reduction in the horizontal force and a better control of the soil flow could be achieved with the modification of the skimmers operating configuration. The skimmer field studies used a modified skimmer to investigate the improved soil and trash flow characteristics at higher speeds. Mathematical models have been developed to predict both the horizontal forces on the mouldboard assembly as a whole, the isolated horizontal mouldboard forces and also the horizontal force of the standard manure skimmer. The prediction was based on Mohr-Coulomb soil theory and inertia effects, with the ability to predict geometrical change for the skimmer as well as depth and speed effects. Both the mouldboard and the skimmer prediction show a good representation of the measured horizontal forces with R-squared values of 97.2% and 65.4% respectively. Finally the work rate of different size mouldboard ploughs was examined and the cost of operation investigated. Methods to reduce the cost of operation were highlighted and the overall cost compared to other tillage systems for a given working period and worked area. The increase in speed was seen as the most beneficial way of increasing the work rate and reducing the cost associated with the ploughing operation. Mouldboard ploughing was shown to be cheaper than minimum tillage up to 125ha (hectares) and cheaper than discing up to 275ha, whereas shallow high-speed ploughing was cheaper than minimum tillage up to 225ha and always cheaper than discing up to a limit depending on workdays.
Open Access
Pricing as a relationship marketing instrument
(2006-03-06) Santschi, Barbara; Crawford, I. M.
Although the principles of relationship marketing are well understood, the role of pricing in building relationships between supply chain partners has not been researched. This study was designed to determine the role, if any, of pricing as a tool for building relationships between suppliers and distributors. A relationship pricing model (RPM) was developed and tested among 83 distributors in the Swiss beverage market, to explore how businesses can define, operationalise and implement a relational pricing system. The research shows that both the process of developing a relational pricing system as well as the output it produces support the adoption of relationship marketing between supplier and distributors. The conclusion reached is that businesses can turn their pricing practices into a relationship marketing instrument if they are dyadic in focus and create mutual longterm benefits for both supply chain partners. An RPM needs to be a pricing mechanism which is fair, transparent, empowers customers to participate in determining pricing conditions and encourages ongoing interaction and communication between supply chain partners. With this research, a major instrument and a step-by-step approach has been created that enables businesses to adopt relational pricing. Directions for future research have been identified. One direction is to set up a longterm study, to investigate the impact of a relationship pricing model over time. Another direction is to build an RPM, which incorporates non-financial incentives and/or additional variables to those investigated during this study.
Open Access
Strategic monitoring of crop yields and rangeland conditions in Southern Africa with remote sensing
(2000-01) Sannier, Christophe; Taylor, J. C.
The monitoring of vegetation resources is of vital importance for Southern African countries because of the dominance of agriculture in the economy. The use of remote sensing techniques in a national or local planning context is particularly adapted to the Southern African conditions because large areas can be covered regularly with minimal requirements for field based infrastructure. Furthermore, relatively low-cost receiving stations have been installed in the meteorological departments and other local institutions, which makes satellite data available in realtime. Real-time acquisition is essential for the operational monitoring of vegetation development and remote sensing plays a significant role in three main areas: • Inventory or mapping of cover types • Monitoring of vegetation conditions relative to the norm • Estimates of biomass In this research operational techniques were developed in each of these areas with the participation and involvement of users. Remote sensing and field survey techniques for inventory and mapping of cover types were adapted and developed from existing experience in the European context to match the requirements in Southern Africa. The need for an unbiased sample of field observations, for the calibration of digital classification of satellite imagery was identified and methodology for its collection demonstrated. Methods developed for the inventory of crop types in Europe were successfully adapted to the African rangeland. The levels of classification accuracy achieved were similar to that obtained in the European context for a classification scheme of equivalent complexity. A Vegetation Productivity Indicator (VPI) was developed for monitoring vegetation conditions based on real-time acquisition of NOAA HRPT imagery from a local receiving station and a historical Normalised Difference Vegetation Index (NDVI) archive. The VPI maps show departure from normal vegetation response using methodology similar to the analysis of extreme events in hydrology, in near real-time. The method was successfully implemented in Zambia to monitor maize production and in Namibia to monitor rangeland. The VPI was significantly correlated with rainfall. The technique was successfully transferred to the Department of Meteorological Services in Botswana where VPI maps are produced routinely and presented to the inter-ministerial drought committee for assessing rangeland conditions. Methodology for rapid biomass assessment was developed using simple physiognomic plant parameters. Field Measurements were taken in four different cover types (grassland, steppe and shrub and tree savanna) and correlated with the NDVI derived from the satellite observations in Etosha National Park, Namibia in near real-time. The pooled regression relationship which was obtained was highly statistically significant. However, the regression model excluding the two savanna types exhibited a higher correlation suggesting that there might be a separate relationship between savanna biomass and NDVI. Biomass maps were produced using the pooled relationship and their potential for operational targeting of areas suitable for prescribed burning was illustrated. Although the methods and techniques in this work were developed using time series of NOAA-AVHRR and the NDVI, they can all be adapted to include data from new sensors systems and other vegetation indices as they become available. Methods demonstrated in this work can be integrated to form a suitable framework for a national vegetation resources monitoring system. This would assist Southern African governments in making decisions related to vegetation resources by providing sound and timely technical advice.
Open Access
Strengthening the local rural economy: promoting the sustainability of rural business in Bedfordshire
(2002-09-25) Reeves, A. J.; Neame, Charles
This research was undertaken for Bedfordshire County Council to investigate appropriate mechanisms for the promotion of sustainable rural business in Bedfordshire. The research seeks to provide insights into the future requirements of small rural businesses in Bedfordshire and to build upon the support that Bedfordshire County Council currently provides to ‘local producers’ through the ‘Made in Beds Directory’. A user-friendly postal questionnaire was targeted to businesses in Bedfordshire with a rural postcode, with 25 or fewer employees and regardless of their business activity. The survey covered: the strengths and weaknesses of the businesses; the perceived importance of those strengths and weaknesses; the barriers to improving business performance; and appropriate support provisions to enhance business performance. These were previously identified in the literature and policy review, corroborated and augmented in a pilot study. The results were varied, illustrating the highly individual nature of the businesses and their perceived requirements. The businesses identified their strengths as: technical expertise; financial management; ability to innovate; compliance with legislation and the location of the business and weaknesses were identified as: marketing and promotional ability; training provision; I.T.; product development and logistics. The perceived barriers to improved business performance identified and future support provision requirements, resulted in the provision of valid insights into the rural businesses. The wide scope of the research meant that despite not fully achieving the objectives, it provided useful insights enabling a series of informed conclusions. The principle recommendations were: • Support should be directed at the agricultural sector; • Support should address the principal areas of weaknesses: marketing and promotional activities; training provision; I.T.; product development. • Support is directed at overcoming the perceived barriers to improving business performance, namely: lack of management time; lack of staff skills; lack of marketing and promotional ability; access to finance; coping with competitors. Further exploratory research should be carried out into: methods for developing the strengths of rural companies and providing strategies for sustainable competitive advantage for the businesses; the types of staff training which rural businesses would participate in to enhance staff skills; Increased promotion and signposting to free local business resources available; Promotion of the benefits of addressing environmental issues in the business decision-making and the provision of free or subsidised membership of the Bedfordshire Green Business Network to businesses with rural Bedfordshire postcodes; BCC to establish a panel of businesses for the purpose of implementing the recommendations on an experimental basis. Over a period of time the panel would provide useful additional data and experiences, which could inform future support strategies for sustainable rural businesses. The use of a pilot panel would allow for the appropriateness of support measures to be assessed prior to implementation thus reducing the risk of inappropriate use of public funding and adverse public opinion.
Open Access
Seawater greenhouse for arid lands
(1997-09) Raoueche, Abdelkrim; Stenning, B. C.; Bailey, B. J.
The growth of the world’s population and the consequent food shortage, requires the expansion of agriculture into arid zones which constitute about 60 % of the earth’s land area and are characterized by high levels of solar radiation and shortage of freshwater. The objective of the seawater greenhouse for arid lands was to develop and demonstrate a cost effective means of producing both crops and pure water in hot, arid coastal regions. The project exploited both the high solar radiation and prevailing wind to drive most of the energy exchange processes in the greenhouse. In addition to a crop grown inside the greenhouse, a shade tent provided shelter for nursery plants and an outdoor planting scheme was maintained with the supply of freshwater as well as protected by the structure of the greenhouse itself. The greenhouse is cooled with an evaporative cooling pad (Celdek™) through which an air flow is promoted by the prevailing wind. The water vapour transpired by the plants combines with the cooled and humidified ventilation air stream to generate a high relative humidity in the exhaust air. A second evaporation pad (Celdek™) is used to further humidify the exhaust air which passes through a condenser cooled by seawater to produce fresh water. The wind also promotes an air flow through a roof cavity in the greenhouse where more seawater is evaporated and the humid air passes through the condenser. A computer program was modified to describe the greenhouse, which at first was triangular in plan, and models were written to describe the evaporative cooling systems, the selectively absorbing roof, the humidification of the air in the roof and the seawater condenser. These models were incorporated into the existing greenhouse model. Analytical techniques were used to create the hourly values of solar radiation, air temperature, humidity, cloud cover and wind speed required by the simulation model. This simulation model was used to predict system performance and determine the sensitivity of the greenhouse environment and fresh water output to air and water flowrates and the climatic conditions. The sensitivity analysis showed that adding the second (rear pad) evaporative cooling pad increased the fresh water production compared to using only the front evaporative cooling pad. The use of cooling water at the wet bulb temperature gave a lower condenser output than using surface seawater. The results showed that an effective desalination system would consist of an evaporating cooling pad coupled directly to the seawater condenser. Data were recorded in the greenhouse in Tenerife in order to determine the heat and mass transfer coefficients of the second Celdek™; these established the program of the system and provided data for validating the model. The experiments performed on a prototype Celdek™ heat exchanger in the laboratory were used to design the Celdek™ condenser. The validity of the seawater greenhouse simulation model was checked using experimental data recorded on the prototype seawater greenhouse in Tenerife, in December 1994 and June 1995. The model was revised as a result of the validation exercise.
Open Access
A GIS based dataset to assess the influence of countryside planning policies on landscape change in Bedfordshire
(1994-02) Peccol, Elisabetta; Bird, Chris A.
A GIS database for a study area (96 Km^) within the county of Bedfordshire (southern England) was established to provide statistical and mapped information on the distribution, extent and change through time of land-cover and landscape features between 1968, 1981 and 1991. A major aim of the project was to investigate the character of the countryside designation zones operating in Bedfordshire in terms of detailed local landscape. The effectiveness of the policies for the countryside was assessed in terms of the landscape changes monitored in each area. To this purpose a census of landscape features was carried out by means of aerial photographic interpretation and the differences between the three dates were measured. The classification scheme included 19 land-cover types (area features), 6 linear features and 6 point features. A Digital Terrain Model was used to analyse the land-fonn of the study area and its influence on the distribution of land-cover types. The countryside designation zones were digitised from the Local Plans and processed with the land-cover maps. The results of the project are represented by maps, tables and charts of landscape features for each date and their changes between each date, in the study area and in the countryside designation zones. The study area is shown to be intensively managed since agro-pastoral and developed land cover most of its area. Countryside designation zones showed a strong agro-pastoral character, except for the Sites of Special Scientific Interest and the National Nature Reserve. Generally, over the two decades analysed, both the study area and the countryside designation zones suffered changes in landscape features.
Open Access
Design of the robotic self-travelling sprinkler system
(1999-08) Ozaki, Yuriko; Blackmore, S.
A conventional rain gun system is adversely affected by windy conditions. Therefore, the robotic self-travelling sprinkler (STS) system that controls the head and the water supply with relation to instant windy conditions. The robotic STS head has two degrees of freedom; sector and trajectory angles, driven by stepper motors to follow the control model, which are found by applying prediction models of water distribution, Centre of volume and Semi-empirical models. As a result, it was shown that the control for the sector angle compensated for the horizontal water distortion from wind, however, the trajectory angle was found to need more data to model the optimum trajectory angle. To control the water supply, a cut-off solenoid valve was installed and shut when wind was over 6 m/s upwind and 7 m/s downwind. This indicated that the trajectory angle was less than 10 degrees above horizontal. Under such windy conditions, water can not be distributed as far from the STS as required or becomes spray, which cannot reach to the ground. As the experimental results showed, the system enabled to minimize the commercially ineffective water distribution. A chemigation system was added, which can injects chemicals into the main water flow. The system enables farmers to save the cost for extra chemigation equipment. The process of the system while working can be checked by the interactive communication system between the embedded computer and the user’s computer. Therefore, this system made the robotic STS system more reliable, furthermore, it enabled the user’s computer to read and save the data sent from the field controller unit. This robotic STS system can distribute water or chemicals to the required area, even if up to the irregular boundaries,(fence lines, comers of fields), with the minimum water supply. Also, the system is ready to incorporate treatment maps and DGPS. In other words, it is possible to feed the adequate amount of water or chemicals which varies depending on the different regions of fields, species of plants, and seasons.
Open Access
Microbial diversity in contaminated soil
(2002-09) O'Flaherty, S. M.; Magan, Naresh; Hirsch, Penny
Little is known about soil population dynamics: how microbial communities are affected by environmental stress; whether they respond adversely, or adjust to it; what the extent and duration of these adjustments might be; which genera of bacteria are the most reliable indicators of soil quality. Inevitably, it is beyond the scope of this thesis to resolve all these issues, but it nonetheless sets out to address specific objectives which should cumulatively enhance our total understanding of the soil microbial environment. A three year study of abiotic environmental stress, using a distinctive multi-disciplinary methodology, examined how pseudomonad communities react to chronic metal pollution from sewage sludge. It deployed three profiling methods: population size, catabolic and genetic diversity, across three sequential sampling times, and processed large numbers of bacterial isolates to facilitate meaningful data analysis. This process required innovative methodologies. Efficient analysis of numerous pseudomonad isolates necessitated semi-automation, by adapting ERIC profiling to run on Genescan, a specialist application for analysing sequence data, hitherto unused to fingerprint soil isolates. Specialist computer programmes were designed to compare multiple isolates. A database system was built to gather ERIC profiles and convert them to generate standardised data for subsequent analysis. The main body of this thesis focuses on the interpretation of genetic relationships, largely derived from ERIC profiles, for which a series of programs was built. Alongside them, the BIOLOG™ technique is deployed to profile catabolic diversity and thus compare the function of environmental samples at different sampling times. Population composition, a third dimension, was examined using conventional plate counts. Initial findings that population diversity might be affected by metal stress were not, in the end, corroborated by the extended study. Both catabolic and population studies proved inconclusive, highlighting only subtle differences between metal-contaminated plots. Soil pseudomonads, in contrast to rhizobia, failed to prove sensitive indicators of low level metal contaminants.
Open Access
An evaluation of the responses of some tea clones to environment in Kenya
(1995-02) Ng'etich, Wilson Kipkoech; Stephens, William; Othieno, Caleb O.
An experiment set up at four sites in Kericho, Kenya was used to investigate Genotype x Environment interactions of four tea clones of commercial and scientific interest. Small differences in environment resulted in large variations in dry matter production and yield between sites and clones. The largest dry matter was from clone TNI 4/3 (291 ha'1) but it had low yield (2.11 ha'1/ 1). By contrast, the largest yield was from clone S15/10 (3.81 h a 'V 1), which gave the smallest dry matter ( I S th a 1). These contrasting responses in dry matter and yield were analysed in terms of the interception of solar radiation, radiation use efficiency, partition of dry matter and components of yield. The differences in clonal dry matter production were attributed to site to site variability in solar radiation and temperature which affected the rates of ground cover development and the solar radiation interception. The differences in yield were attributed mainly to differences in air temperature and saturation deficits of the air between the sites which affected the shoot replacement cycles through rates of shoot extension and development. Differences in measured and derived environmental variables between the sites were found. Incident solar radiation differed between the sites by up to 2.4M Jm 2 d 1. Differences in mean air and soil temperatures between the extreme sites were 2.5 °C and 3 °C respectfully. A lapse rate of 6.1 “Ckm*1 for mean air temperature was found. Annual rainfall amounts also differed between the sites by up to 700 mm. There were no differences in wind speeds, but there were large differences were in saturation deficits (0.5 kPa) and évapotranspiration (1 mm d*1). During the course of the experiment light interception ranged from less than 5% at planting to more than 80% in April 1994. Radiation use efficiencies for dry matter ranged from 0.30 to 0.45 g MT1 in the clones studied and appeared conservative with respect to temperature across the sites. Clone TNI4/3 had the lowest base temperature for shoot extension (6.1 °C), while clone BB35 had the highest (10.4 °C). The base temperatures for shoot extension were 1.3 to 2.9 °C higher than those for development, hence the differences in shoot lengths between sites. Shoot replacement cycle ranged from 57 days to 110 days between the sites and was the main determinant of yield. Abstract Silsoe College WK Ng’etich PhD. 1995 CranfisM,m The dry matter content of shoots varied between sites and seasons and ranged from 18% to 33%. Mean shoot dry mass was inversely proportional to temperature, ranging from 6 to 12% difference between extreme sites. Loss in yield due to water stress during the dry seasons ranged from 14 to 20% across the sites. Yield losses due to ‘hut sites’ ranged from 10 to 50%, while that from hail damage accounted for up to 20% of annual yields. These results are discussed in the light of other work in Kericho and southern Tanzania. The thesis concludes by considering the implication of the results for the tea industry.
Open Access
Towards the molecular diagnosis of bladder and colorectal cancer : Analysis of CD44 exon splicing
(2002-08) Morgan, Sarah Louise; Woodman, Anthony C.
The literature suggests that CD44 has the potential to be used as a non-invasive tumour specific marker for early detection and monitoring. The gene transcript can undergo alternative splicing, leading to the production of a number of isoforms and it has been noted that in neoplastic states this splicing becomes abberant, leading to the production of a number o f variant isoforms. The aim of this study was to analyse CD44 variant expression with the goal o f reaching a platform from which a non- invasive assay for routine clinical use could be produced. In this study, the analysis o f exon junction splicing in bladder cancer has also led to the finding of a tumour specific junction expressed in 64% o f tumours studied. This exon junction (5/11) was found to be the same as that expressed in colorectal cancer. Though mRNA based assays would provide a satisfactory method for exon junction identification, a protein based approach would provide the platform for a more robust assay. Translation of gene expression data led to the design of a short synthetic peptide which overlapped the 5/11 junction, and this was used to produce a novel polyclonal antibody for this transitional epitope. The resulting polyclonal antibody was affinity purified and used in a pilot study of 5/11 expression in bladder and colorectal tumours. In bladder tumours the antibody demonstrated an overall specificity o f 76.5% and an overal sensitivity of 73.1 %, comparable to current commercially available early detection assays. In a Dukes staged colorectal cancer study, no link between stage and grade was noted, but the antibody gave an overall specificity of 76%. Though further analysis is required, it is thought the 5/11 antibody may prove to be a useful tool in the development o f a sensitive and specific assay for the non-invasive detection of bladder and colorectal cancer.
Open Access
A peroxide sensor for the food and beverages industry
(2001-11) Moody, A. P.; Saini, S.
Due to desirable environmental reasons, peroxides have replaced halogenated substances for disinfection purposes in the food and beverage industry. However, cost issues and the requirement to completely remove these agents after disinfection necessitates simple, low-cost and sensitive test methods with a wide dynamic range and on-line capability. The development and performance of such a method is detailed in this thesis. The novelty of this work was in the simplified production of the sensor by pre-mixing all active components before application onto a screen-printed graphite base electrode in a single step. Having established the principle of pre-mixing all the components, the proportions were optimised with regard to a balance between cost and required performance in the industrial application. Once this had been established, the performance and stability was evaluated in the laboratory, a comparative study was performed against other methods for hydrogen peroxide determination and finally the sensor was demonstrated to work in a small-scale industrial field trial. Some of the available mass-production processes for the sensor were considered for suitability and a recommendation made. The relative analytical performances of sensors produced manually and by the recommended process were compared to their visual appearance under a microscope and a possible quality control process suggested for the manufacturing stage. Finally, a scanning electrochemical microscope was commissioned and a method for producing ultramicroelectrodes for use with it developed. This was then used to study the variation of the sensor surface coating with the aim of facilitating the optimisation of the composition, production and quality control processes.
Open Access
Erosion hazard assessment in the upper Ewaso Ng’iro basin of Kenya: application of GIS, USLE and EUROSEM
(1999-09-15) Mati, Bancy Mbura; Morgan, R. P. C.; Gichuki, F. N.; Quinton, J. N.; Brewer, Timothy R.; Liniger, H. P.
A methodology was developed for assessing soil erosion hazard in the Upper Ewaso Ng’iro basin of Kenya, using Geographic Information Systems (GIS), the Universal Soil Loss Equation (USLE) and the European Soil Erosion Model (EUROSEM). The USLE was used in a GIS environment by creating thematic maps of R, K, L, S, C and P and then calculating soil loss by raster-grid modelling with Arc/Info GRID. The rainfall erosivity factor (R) was derived from relationships between rainfall amount and erosivity using erosion plot data from within the catchment. The nature of the relationship was found to be a function of agro-climatic zones of the region. Mean annual erosivities ranged from 145 to 990 J m'2 hr'1. For a given amount of rainfall, erosivity was higher in zone IV than in the wetter zones II-III. The soil erodibility factor (K) was estimated using the USLE nomograph and data from laboratory analysis of field samples collected from representative major soil mapping units. The K-values were low to medium, ranging from 0.10 to 0.25 over 84 percent of the basin. The topographic factor (LS) was obtained by creating Digital Elevation Models (DEMs) of the basin with TOPOGRIDTOOL of Arc/Info. These were then used to determine the slope steepness and length factor values, calculated with raster-grid modelling. Although DEMs proved a useful tool, maximum values of both steepness and length had to be set in this reconnaissance study to achieve reasonable results. A finer resolution of input data and a smaller grid cell size are needed for accurate determination. The cover and management factors (C) were obtained by determining the land cover types within the basin using remotely sensed data (SPOT 1 colour composite prints) and ground truthing studies. The factor values were estimated from USLE guide tables and measurements of cover from plots and test sites. Some 70 percent of the basin is covered by rangelands. The conservation practice (P) factor values were estimated from USLE guide tables and then applied to areas where soil conservation had been introduced according to maps obtained from the Ministry of Agriculture. The USLE was validated using data from erosion plots. A value of R2 = 0.645 was obtained between predicted and measured values but the standard error was rather high (e = 5.745 t ha’1 yr'1). Using an annual soil loss of 9.0 t ha'1 yr'1 as tolerance level, some 36 percent of the basin was found to experience unacceptably high erosion rates. Most of this area was communal grazing land and cropland where soil conservation measures had not been applied. A critical land cover type within the grazing land is shrubland, where vegetation cover is less than 40 percent and high erosion risk was predicted and confirmed by field surveys. EUROSEM could not be integrated within a GIS in the time available for research. It was therefore simulated outside GIS environment, where it was applied to Embori and Mukogodo plot data using separate data sets for calibration and validation. Calibration was used to obtain input parameters for saturated hydraulic conductivity, cohesion and Manning’s roughness coefficients. Validation gave correlation coefficients of 0.907 and 0.840 for predictions of storm runoff and soil loss respectively at Embori; the corresponding values for bare soil plots at Mukogodo were 0.895 and 0.577. However, EUROSEM predicted runoff poorly (R2 = 0.570) and failed to predict soil loss at all the vegetated plots at Mukogodo. The model was applied to simulated vegetation covers of barley, maize, grass and forest for a 36.7 mm rainstorm at Embori. The simulated soil losses showed an exponential decrease with increasing cover. At a threshold cover of 70 percent, soil loss diminished to zero under grass and forest and decreased to a minimum value under barley and maize. These results support the USLE simulations, which showed that areas with more than 70 percent cover (such as forest) had a low erosion hazard, even with steep slopes and high rainfall erosivities. This research has demonstrated that GIS can be used with the USLE to assess and quantify erosion hazard, giving results that can be used for conservation planning. EUROSEM can be applied successfully to bare soil and cropland, but application to other land covers requires further investigation. Land cover and topography are the main factors controlling the spatial distribution of soil loss in the Upper Ewaso Ng’iro basin. Future conservation activities should be concentrated on the rangelands.
Open Access
Novel food applications of electronic nose technology for detection of spoilage fungi
(2001-10) Keshri, G.; Magan, Naresh
This work investigated the potential use of the electronic nose ( e-nose) for the rapid and early detection of fungal spoilage in intermediate moisture bakery products. Four xerophilic Eurotium spp., Penicillium chrysogenum and Wallemia sebi were grown on 2% wheat meal agar (WMA, 0.95 aw) at 25°C. Discrimination between the fungal species and the control media based on their volatile patterns was possible after 48h, using the Bloodhound BHl 14 e-nose. Volatile patterns produced by four Eurotium spp. and the Penicillium sp. were also investigated on WMA at different water activities (0.95, 0.90 and 0.85). Enzyme assays using p-nitrophenyl substrates were used as an indicator of spore germination and growth, and compared with volatile patterns and growth rates. Only three of the seven enzymes assayed were found to change significantly i.e. N-acetyl-P-D-glucosaminidase, a-D-galactosidase and P-Dglucosidase. Earlier detection and differentiation of the control blanks and the fungal species were achieved after 48h incubation, using the e-nose when compared to enzyme assays. In vitro study of volatile profiles from mycotoxigenic (Aspergillus flavus, A. ochraceus and W. sebi) and non-mycotoxigenic (A. niger and P. chrysogenum) fungi grown on WMA media demonstrated that differentiation of control blank media from the spoilage fungi was possible after 72h growth. Work on different mycotoxigenic and non-mycotoxigenic strains of Fusarium moniliforme and F. proliferatum showed that the e-nose could discriminate between the control blanks and the different strains after 48h growth. For all these studies the same three enzyme activities were found to be significant as in the previous work. Furthermore, the e-nose could detect fungal spoilage earlier than the enzyme assays. Volatile patterns produced by two Eurotium spp. and P. chrysogenum colonising a bread analogue modified to 0.95 aw at 25°C could be discriminated from the uninoculated bread after 40h incubation. This suggested that e-nose systems could be an earlier detection tool than enzyme assays. Furthermore, the same enzyme activities were found to be predominant as that observed for in vitro studies. E. chevalieri and P. chrysogenum were used to determine the limit of detection on a bread analogue (0.95 aw) using three inoculum concentrations (102 , 104 and 106 spores mr1 ). The initial spore concentration of 106 spores mr 1 treatments and the uninoculated bread analogue could be discriminated after 24h incubation. In another study, the volatile patterns produced by two Eurotium spp. and P. chrysogenum in the presence of potassium sorbate were measured. The uninoculated bread substrate and those colonised by the spoilage fungi could be discriminated after 48h growth. The study was repeated using calcium propionate and differentiation could be achieved only after 24h incubation. In the final study, volatile patterns produced by two Eurotium spp. and P. chrysogenum growing on natural bread substrate could be differentiated along with the uninoculated bread after 24h growth prior to any visible signs of growth. Overall, this study suggests that for the first time e-nose systems could be used to detect qualitative changes in volatile patterns for early and rapid detection of activity of the spoilage moulds in bakery products.
Open Access
Early detection and monitoring of fuel leaks
(2005-08) Huntley, Sharon L.; Setford, S.
A novel integrated detection system· has been developed to protect the environment from hydrocarbon fuels leaking from large-scale storage facilities. Over the last decade, land and subsequent groundwater contamination from hydrocarbon fuels has been identified as the major threat to drinking water resources across Europe and the United States. The integrated system developed within this work has two main components: (1) 'Early warning' free-phase fuel leak detection sensors; (2) A novel immunoassay field test for rapid, in situ follow-up analysis of contaminated sites through determination of the extent of the contamination and early indication of dissolved-phase fuel migration. (1) A prototype optical reflectometric device has been developed, in conjunction with state-of the-art data acquisition and relay technology to provide a simple, low-cost hydrocarbons monitoring solution. In extensive field trials, this system has been evaluated as a multiple-array, sub-surface, remote leak detection and monitoring system for early detection of free-phase hydrocarbon contamination. The sensors respond to all. free phase hydrocarbons and can determine plume movement through soil. Preliminary leak information from these sensors can be combined with subsequent, quantitative site analysis using the immunoassay to provide an integrated, highly sensitive and low-cost solution for long term monitoring and analysis. (2) A novel ELISA has been developed for detection of the most controversial fuel oxygenate - \ methyl tert-butyl ether (MTBE), identified as the most major threat to groundwater (and consequently drinking water) resources above any other hydrocarbon contaminant. The ELISA is a classical competitive immunoassay involving free MTBE and a novel antigen consisting of an MTBE analogue covalently bound to BSA. The ELISA was optimised and transposed into a magnetic bead format, the detection range was 0.5-5000 ppm (IC50 5 ppm, assay time 65 minutes). Also detectable are MTBE degradation products TBA, TBF and alternative fuel oxygenates TAME, DIPE and ETBE. MTBE is highly soluble in water and so is an excellent marker for assessing the extent of site contamination. This integrated detection system potential provides a sensitive, cost-effective solution for early detection, analysis and surveillance of petroleum fuel contamination in a range of applications.