Mitigating the impacts of intensive agriculture on lowland organic soils

Lead Research Organisation: Bangor University
Department Name: Sch of Environment and Natural Resources

Abstract

Optimising the trade-off between food and fibre production, and the other services provided by semi-natural and agricultural ecosystems, represents a key global challenge. This challenge is particularly acute in organic soils, both in the UK and globally, due to inherent unsustainability of drainage-based production in former wetland soils. The IPCC estimate that peatland degradation accounts for 3% of all anthropogenic greenhouse gas (GHG) emissions, whilst cultivated organic soils are the UK's largest source of emissions from the land-use sector. Carbon loss and associated land subsidence in areas such as the East Anglian Fens were identified as major threats to UK soils in the recent House of Commons report on Soil Health, with long-term consequences for agricultural yields, rising energy costs of drainage, and flood risk. Nevertheless, drained lowland organic soils currently represent some of the UK's most valuable and productive agricultural land, and are particularly important for the horticultural sector. Whilst re-wetting and restoration of some formerly cultivated organic soils is now taking place, the long-term maintenance of UK agricultural and associated economic output requires their continued cultivation over a large proportion of the existing farmland area. Consequently, there is a pressing need to develop proven methods to mitigate the rates of carbon and GHG emissions loss, and reduce subsidence rates, from these areas.

This project aims to test novel methods to mitigate GHG emissions from organic soils under cropland and intensive grassland cultivation. By working within a new large NERC research programme (ASSIST) involving CEH and Rothamsted research, and making use of a range of cutting-edge instrumentation linked to this and other projects the student will have the opportunity to undertake world-leading research, and to help in the development innovative solutions, ranging from nature-based to agri-tech approaches, to a major global environmental challenge.

Publications

10 25 50
 
Description My project set out to understand if we can preserve cultivate peat soils whilst at the same time maintaining the current levels of food production. I am looking at different ways we can preserve these important soils, the options I have so far looked at are 1) increasing the water table and 2) adding crop residue left over from crops that are grown as cover crop. The use of increased water table has proved to be successful as it led to decreased greenhouse gas flux. However, adding crop residue worsened the situation. This further complicates the situation as the use of cover crop and addition of crop residue has been promoted as a solution the to the problem of cultivated peat loss. A follow experiment is going to investigate the legacy of the crop residue in the next growing season. I will have results of this follow-on experiment later this year.
Exploitation Route The outcomes, helps us understand how cultivated peat soils respond to increased fresh organic matter. The addition of fresh organic matter has been long promoted as a mitigation measure to peat loss. However, this notion is not supported my the findings from this project.

Understanding the best approach to prevent peat loss requires evidence. The outcomes from this experiment will hopefully help farms decide how they will best manage the precious peat soils.

Whilst cover crops can help with wind erosion, their residue is not good for cultivated peat soils.
Sectors Agriculture, Food and Drink,Environment