School of Applied Sciences (SAS) (2006-July 2014)

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Browsing School of Applied Sciences (SAS) (2006-July 2014) by Course name "Land Management"

Now showing 1 - 3 of 3
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    Assessment of an innovative soil aerator on soil physical disturbance and reducing runoff on compacted grassland
    (Cranfield University, 2009-09) Shanahan, Peter; Simmons, Robert W.; Hann, Michael J.
    Poor grassland management practices increases compaction and reduces infiltration leading to increasing risk of poaching and runoff generation. On-site impacts of grassland compaction include the loss of topsoil structure which also reduces soil ecosystem functioning. In addition, ongoing diffuse water pollution from compacted grassland limits the ability of the UK’s authorities to meet EU water quality guidelines such as the Water Framework Directive and address flood risks in areas of extensive grassland management (e.g. Boscastle, 2004). This study investigates the effects of an innovative ground-driven rotary soil aerator at alleviating soil compaction and reducing overland flow (designed by Mr. Roger Clay, Herefordshire). The magnitude of soil disturbance from slotting was assessed at the Cranfield University Soil Dynamics Test Centre soil-bin. Draught and vertical force requirements and tillage efficiency were also determined for varying depth and horizontal and vertical angle combinations using an Extended Octagonal-Ring Transducer (EORT). The effect of various slotting treatments on runoff was then investigated on a steep compacted permanent pasture in Herefordshire using erosion plots and simulated rainfall. From the soil-bin assessment, soil disturbance was most efficient (lowest specific draught) at 100 mm depth, a vertical angle of 18° and with increasing horizontal angle (0° to 10°). The draught requirement for a single bladed disc at 18° vertical ranged from 0.88 to 1.24 kN (90-126 kg force) and a maximum vertical force or ballast requirement of 257 kg force per bladed disc. Slotting treatments reduced runoff by 75% as compared with the non-slotted control.
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    Determining the carbon footprint of a National Trust country estate
    (Cranfield University, 2009-09) Slater, Dora; Burgess, Paul J.; Williams, Adrian
    The UK Government aims to reduce greenhouse gas emissions by 80 % by 2050 against a 1990 baseline. Agriculture makes up around 7 % of UK emissions and the industry is under pressure to meet these targets (and to produce more food). To achieve reductions it is necessary to be able to calculate emissions. This study looks at methods to calculate the carbon footprint of a National Trust estate with livestock, arable farming and a stately home. Methods explored include greenhouse gas inventories, life cycle analysis and carbon calculators. A carbon calculator designed for farms was selected (the CALM Calculator) and applied to Wimpole Hall, Cambridgeshire. Key greenhouse gas sources were identified and estate activity data gathered to calculate the footprint. A comparison was made between current arable practices and proposed organic methods. Emissions from estate energy and water consumption were also included. The arable non-organic farm emitted 1018 tCO2e, 73 % due to N2O emissions from nitrogen fertilizers. The livestock farm emitted 686 tCO2e, 44 % from cattle. Estate emissions from electricity, heating oil and water supply were 303 tCO2e. The total estate footprint was calculated as 2007 tCO2e. A change to organic arable methods was predicted to deliver an estate footprint of 1361 tCO2e but yields will be less (organic wheat is said to yield only 68 % of non-organic). The removal potential of conversion of areas of arable to grassland (41 tCO2e) and particularly of farm woodland (1430 tCO2e) was noticeable. Combined these can offset 73 % of total estate emissions using non-organic arable methods and 103 % of total estate emissions using proposed organic arable methods. Shortcomings of the method are identified along with the high level of uncertainty connected to the results. The issue of reduced yield expected under organic arable cultivation is highlighted and the implications of balancing reduced emissions with maintaining food production are explored.
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    The effects of a thermal conditioning treatment forweed control upon soil biological properties
    (Cranfield University, 2009-09) Amis, K. S.; Ritz, Karl.; Pawlett, Mark
    Weeds, and their associated control, are often significant in limiting production within organic farming due to restrictions on herbicide use within such systems. Organic farmers rely on alternative weed control methods, including soil thermal treatments. Preliminary research has shown soil steaming to be a potentially effective weed control method, but procedures have yet to be fully explored and implemented. One issue is the effect steam treatment has upon the non-targeted components of the soil system. This study considered the magnitude and persistence of the effects that soil steaming had on biological aspects of soil systems within the organic production of Daucus carota, sativus (L) (carrots). A field-based study was conducted whereby soil treated with steam was sampled at intervals of 1 hour, and 14 and 42 days following treatment. Impacts upon the soil system were then assessed by measuring a range of chemical and biological properties related to carbon and nitrogen cycling. Immediately following steaming, actual nitrification was inhibited with an associated accumulation of ammonium-N, displaying an initial low resistance to the thermal treatment. However, recovery of this process was apparent at approximately 14 days post-treatment with a significant rise in both nitrate-N and potential nitrification, indicating a degree of resilience of the nitrification process. Overall, other measured components of the soil system, including microbial activity and organic carbon, also demonstrated signs of resilience, indicating that the system still had the ability to function and provide its regulatory and provisioning services within the short-term following soil steaming treatment.