Guest Editorial

Abstract

In September 2009 the British Society of Soil Science held a joint meeting with the Soil Science Society of Ireland at the Teagasc Environmental Research Centre, Johnstown Castle, Co Wexford, Ireland. The title of the conference, “Soil quality: does it equal environmental quality?” posed a significant question for soil and environmental scientists at a time when the proposed Soil Framework Directive seemed to be stalling in European political circles. As soil scientists we have become familiar with the concept of soil quality, but we need to ask some critical questions; what is the significance of soil quality? What can soils do for the wider environment? What are the benefits to the biosphere, agriculture and humanity of improved soil quality? What are the threats to soil quality and what is the extent of these threats in Britain and Ireland? A selection of four papers, volunteered by presenters at the conference, are brought together in this issue of Soil Use and Management. Some other papers will appear in later issues of the journal. The conference addressed soil quality issues as they relate to key ecosystem processes such as the relationship between soil quality, habitat and biodiversity, role in carbon sequestration processes, interaction with plant growth, nutrient cycling, water quality and critical infrastructure. Examples were provided of the multi-functional role of soil within the wider environment, i.e. providing more than one supporting function at any one time. These included a potato-experiment in Canada, where the landspreading of external carbon sources, in this case residue from the paper-industry, had simultaneously increased soil carbon levels and productivity. The key-note speaker, Prof Johan Six (University California Davis), presented examples from the USA, Latin-America and Africa, where the combined input of organic and mineral fertilisers (as opposed to relying on either source only) had consistently increased agricultural productivity and environmental quality. However, caution must be taken when we try to manipulate soils by selectively increasing individual soil functions at the cost of others e.g. the current political debate “increase food production or increase carbon-sequestration capacity”. The conference heard an example from New Zealand where an attempt to increase grass productivity through irrigation had reduced the carbon-sequestration potential and increased risk of nutrient losses. Similarly, in the UK, attempts to build-up carbon stocks on tilled soils by the application of livestock manure may simply have resulted in a redistribution of carbon around the landscape, from grassland to tillage soils, with little benefit to the overall carbon balance. The consensus from the conference was that the challenge for soil researchers is to develop a toolbox for land managers to ensure sustainable production, while safeguarding the soil’s capacity to provide a range of functions. We also need to further understand the range of functions that our soils are capable of providing under different landscapes – understanding the role of functional planning of soils, as in many countries the extension of urban areas has resulted in the loss of some of the best agricultural soils. At a European scale Dr Claudia Olazabal (DG-Environment, Brussels) provided us with an overview of the role of the SFD and the status quo in Europe, with blocking of the Directive by five member states; Germany, France, Austria, the Netherlands and the UK. Within this issue there is a paper on the implications of the proposed SFD on agricultural systems in Atlantic Europe which surmises that while much legislation exists at member state and European level which is applicable to soils, the SFD is desperately needed to unify the protection of soil functions across Europe to provide a level playing field for the role of soils in the production of food and environmental resources.