1Introduction: the importance of soil to society
1.Soil, water and air are all essential to human life and society—but of these three, soil is often the forgotten component. Soil plays a crucial role in many aspects of a functioning modern society, including agriculture, food security, climate change mitigation, and flood risk management.1 Soil makes it possible for plants to grow: 95 percent of the world’s food production is reliant on soil. Agricultural production from UK soil is worth £5.3bn per year.2 Soil supports urban development, providing a mechanical foundation for infrastructure and housing. Soil stores and regulates water and so assists in flood risk management. Healthy soil stores a large amount of carbon and so helps protect against climate change. By contrast, degraded soil emits carbon into the atmosphere, potentially speeding up climate change. Soil is home to a quarter of the earth’s biodiversity including earthworms, fungi and bacteria which maintain its fertility and provide raw materials for the medical industry.3
2.The UK’s soils are relatively young, having been formed around 10,000 years ago after the last ice age. By comparison, some soils in Africa and Australia are thought to have formed 65-144 million years ago.4 Soil grows slowly—it takes an average of 100 years to generate 1cm of topsoil.5 Since any soil loss is not recoverable within a human lifespan, soil should be regarded as a non-renewable resource.6 Nevertheless, we heard that soils are sometimes managed as if they were abundant resources.7
3.Soil is a ‘Cinderella’ environmental issue. Despite soil health underpinning many functions of society, we were told repeatedly that it does not receive due attention relative to other issues such as air quality, water quality and biodiversity—either in terms of statutory protection, Government policy attention, or public interest.8 We also heard evidence that the UK’s soils are in increasingly poor condition. Research has suggested that the UK’s agricultural capacity is in danger,9 that the current rate of soil erosion is 10-100 times higher than it has been in the past, and that 2.2 million tonnes of soil is eroded each year in the UK.10 It was estimated in 2011 that the cost of soil degradation in England and Wales is between £0.9 billion and £1.4 billion per year.11 The main costs relate to greenhouse gas emissions, agricultural costs, loss of productivity, and flooding as a result of soil degradation. Degradation is likely to be further increased by climate change: warmer and drier weather may increase the decomposition of organic matter within soils, leading to carbon losses and increased greenhouse gas emissions, whilst more extreme rainfall events will increase erosion risk.12
4.The increase in urban development and our industrial heritage are also contributors to soil degradation. An estimated 300,000 hectares of land in the UK are affected to some degree by contamination. 13 Past industrial sites have left a legacy of soil contaminated by the disposal of waste materials on site and the demolition of building containing toxic elements, such as cadmium, arsenic and lead, at levels which are detrimental to human health. This contaminated land restricts the use of brownfield land for urban development.14
5.Soil can be defined as “a dynamic natural body on the surface of the earth in which plants grow, composed of mineral and organic materials and living forms”.15 Soil health is multi-faceted, depending on a range of biological, chemical and physical factors. Key components include: nutrients and acidity; organic carbon content; structure and water capacity; biological activities; and chemical pollution (particularly in urban soils).16 Since soils are highly variable, any assessment of soil health has to be context dependent. For instance a healthy peat has very different properties to a healthy arable soil.17
Our inquiry
6.The Government has ambitious policy goals for soil management. In its 2011 Natural Environment White Paper, it announced an aspiration that soil should be managed sustainably by 2030.18 Some of our witnesses expressed doubt that this aim could be met on the current trajectory.19 The aim of our inquiry is to investigate whether the Government’s action matches its ambition on soil health.
7.We held four evidence sessions and questioned a range of experts including academics, farming representatives, practitioners, and professional bodies. We received over 70 pieces of written evidence. A full list of witnesses can be found at the end of this report. We are grateful to everyone who gave evidence to this inquiry. We would also like to thank our specialist adviser Professor Bridget Emmett of the Centre for Ecology and Hydrology.
1 Centre for Ecology and Hydrology (SHI72); Wardell Armstrong LLP (SHI69); Dr Arwyn Jones (SHI76); ADAS UK (SHI23); Willie Towers (Q1); CIWEM (SHI15)
3 James Hutton Institute (SHI52); STARS (SHI55); British Geological Society (SHI36); CIWEM (SHI15); British Ecological Society (SHI58); Dr Tim Harrod (SHI09); Prof Mark Hodson (SHI03); Institute for Global Food Security (SHI64); Lancaster Environment Centre (SHI14); Microbiology Society (SHI74); Soil Security Programme (SHI48); Robert Palmer (SHI10); Soil First Farming (SHI65); STARS (SHI55)
4 Macaulay Institute, The Soil Beneath Your Feet
6 UN FAO, Soil Infographic; Reading Agricultural Consultants (SHI73); Scotland’s Rural College (SHI22)
8 Prof Richard Bardgett (SHI49); Soil Security Programme (SHI48); Soil Association (SHI62); The Geological Society (SHI51); Wardell Armstrong LLP (SHI69); S Atkinson (SHI8); ADAS UK (SHI23); Willie Towers (Q1); CIWEM (SHI15); Compassion in World Farming (SHI42); Soil Security Programme (SHI48); Newcastle University (SHI63); Newcastle University Student and Staff Soil Science Society (SHI31); RCUK (SHI53); David Powlson (Q81)
9 Edmonson et al 2014, Urban cultivation in allotments maintains soil qualities adversely affected by conventional agriculture, Journal of Applied Ecology; See also Sustainable Food Trust (SHI78)
10 Rothamsted Research (SHI18); Centre for Ecology and Hydrology (SHI72); James Hutton Institute (SHI52); The Woodland Trust (SHI38)
11 Graves et al, The total cost of soil degradation in England and Wales
14 Centre for Ecology and Hydrology (SHI72); Smart Growth UK (SHI29). Note that contamination is not limited to brownfield land and can also affect greenfield sites (Howard Price, Q134).
15 Brady, N.C. (1974). The Nature and Properties of Soils. New York: MacMillan
17 Rothamsted Research (SHI18). See also APPG on Agroecology (SHI40); Dr Tim Harrod (SHI09); National Farmers’ Union (SHI44); National Trust (SHI68); RCUK (SHI53); Martin Rogers (Q6).
18 The Natural Choice: securing the value of nature, Defra, 2011
19 Lord Krebs (Q40); David Powlson (Q81)
© Parliamentary copyright 2015
27 May 2016