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Title: An investigation into farming practice and the maintenance or improvement of soil organic carbon levels
Author: Deeks, Katherine Suzanne
ISNI:       0000 0004 5372 7967
Awarding Body: University of Exeter
Current Institution: University of Exeter
Date of Award: 2014
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Due to growing global concern regarding climate change and CO2 emissions, the use of soil as a potential carbon (C) sink has become increasingly recognised as a potential mitigation measure. Global agricultural soil has the estimated capacity for sequestering C at around 20 to 30 Pg (Peta grams) of C over the next 50 to 100 years if correct land management practises are applied. The benefits on improving soil C levels are not limited to reduced CO2 emissions and climate change mitigation however. It is widely accepted that improved organic C levels provide an array of positive benefits, including enhanced soil fertility, soil structure and water holding capacity and generally improve soil biodiversity and associated ecosystem services. Therefore, the pursuit of increasing soil organic carbon (SOC) levels in agricultural soil could create a win-win-win scenario. To improve SOC levels in agriculture, there are two key components that need to be fully effective. The first being the scientific understanding of SOC and its responses to different farming practices and systems. Secondly, the policy and advisory environment needs to be effective and conducive, promoting those practices and systems which are proven to increase SOC levels. This research therefore, explores these two components by conducting a series of investigations into current on-farm practices for managing SOC, the current policy and legislation structure, the quality and extent of farm-facing SOC related advice, and the scope for improving SOC levels through farm management practices and agri-environmental policy. A critical review and synopsis of global, European and national policy and advice was conducted to identify those policies that encourage the improvement of SOC and to highlight those areas where SOC does not currently feature as a management issue. Whilst soil and SOC do not feature heavily at the European or national level, there are a number of mechanisms which have the potential to improve SOC levels through their ability to reach a large audience of farmers and via the promotion of suitable management practices. The review of current policy was supplemented by interviews with those responsible for providing advice to farmers and farmers themselves. The interviewed farmers and advisors were relatively engaged with the subject of SOC although the results demonstrated that there was scope to improve current levels of understanding and practice. The currently policy environment at the national level, was not, in general, creating changes in management practices with those interviewed, so any potential enhancement of SOC that the policy mechanisms had the ability to create, were being missed. A review of the scientific literature regarding SOC and data gathered from subsequent soil sampling under a range of farming practices has allowed for the exploration of the potential and realisation to increase SOC levels through various management approaches. Practices which promote an increased use of organic matter amendments, reduced tillage systems and organic farming systems were of particular focus; with all three demonstrating the potential in improve SOC levels. Combining the social and natural science aspects of the issue of SOC has allowed for an exploration of the potential approaches to improve SOC within English agriculture. Critically, research and development of the subject needs to be improved to further the scientific understanding of SOC in relation to farming practices and land use. Development is also required of current national policy, in particular agri-environment schemes (AES), which despite reaching a wide farming audience, would appear to create minimal management changes and therefore has minimal impact on improving SOC levels. The two sides of this issue, the social and the natural sciences, must be addressed together otherwise a full understanding and an appropriate approach forward cannot be reached. This is why an interdisciplinary approach has been viewed as a suitable research framework for this thesis. The concluding aim of this work is to present a ‘best practice approach’ in terms of physically improving SOC levels by enhancing current advisory pathways and developing an effective policy environment.
Supervisor: Buller, Henry ; Quine, Timothy Sponsor: NERC ; ESRC
Qualification Name: Thesis (Ph.D.) Qualification Level: Doctoral
EThOS ID:  DOI: Not available
Keywords: Soil Organic Carbon ; Agricultural Policy ; Farming Practice ; Farm Management ; Farming Advice ; Interdisciplinary Research