Leading soil scientists today showcased important new techniques for
measuring soil degradation and fertility and called for greater global recognition of the critical role soil plays in determining the health of the planet, affecting a range of the Earth's ‘vital signs' ranging from food production to flood prevention and management.
The call came during a session of the annual meeting of the American Association for the Advancement of Science (AAAS) in Boston, as scientists presented a range of new techniques which permit unprecedented levels of detail and accuracy in ‘soil mapping'.
Despite an increasing realisation by scientists and policy makers of the crucial role that soil plays in such areas of the ecosystem as food production, the provision of clean water, the generation of greenhouse gas sinks, the provision of raw materials and the preservation of the gene pool, soil survey is a declining activity. This was one of the key messages put forward by scientists during a symposium entitled "Soil Protection for Sustainable Well-Being".
Soil survey has not changed that much over the last 50 years. Traditionally, surveyors dug pits in the ground to examine soil characteristics. Based on this information and on their reading of the landscape, approximate boundaries between different soil types were drawn.
Digital Soil Mapping (DSM) provides soil scientists with a set of new tools to help them map soil characteristics by integrating laboratory and field data with innovative mapping techniques.
Through geo-statistical concepts, DSM can provide ground-breaking datasets in a way that traditional soil survey could not and at the same time supply complete coverage of the territory under investigation.
European Science and Research Commissioner Janez Potočnik, attending AAAS for the first time added: "We definitely undervalue the contribution of soil to our bio-diversity, but unless we protect it better, we will soon realise its importance in the worst possible way. Soil is an immensely valuable but finite resource, which requires protection to ensure future food security and environmental quality."
Symposium organizer Luca Montanarella of the European Commission's Joint Research Centre (JRC) said the reason for the decline in soil mapping was the time-consuming and expensive nature of traditional methods for the collection of reliable information.
"Soil is a living system and once destroyed it is lost forever," he added. "Erosion, contamination, decline of organic matter content, landslides and flooding all contribute to the degradation of a resource that is fundamental to our survival".
Around 16% of the European Union's territory is affected by some sort of soil degradation. In many parts of the world, the ‘sealing' of soil due to housing and infrastructure development is progressing at an alarming rate. In Germany this has been recorded at more than 100 hectares per day. Soil sealing can severely affect the natural hydrological cycle. The loss of soil to urban surfaces contributed significantly to the recent cases of severe flooding in Europe.

According to speaker Jonathan Hempel from the National Geospatial Development Center of the United States Department of Agriculture, the decline in soil surveying makes it all the more important that alternative and innovative methods should be investigated to collect crucial soil information.
Soil scientists representing a global consortium of experts dedicated to shedding new light on the state of the soil on the planet (see note to editors), stressed the growing importance of remotely sensed data from satellites and sophisticated geo-statistical models. These novel approaches are referred to as Digital Soil Mapping (DSM).
The session heard that Digital Soil Mapping combines information acquired by a host of new technologies, including GPS receivers, field scanners, and remote sensing with related environmental datasets (e.g. digital elevation models) for subsequent processing by novel computational methods, such as geo-statistical interpolation, inference algorithms and Geographical Information Systems (GIS).
Key benefits of DSM include the generation of large scale geo-spatial datasets that can provide soil information on the Earth's surface at very high resolutions (for example, every 100 metres or in some cases, even every 10 metres) and, as a result of the predictive power of DSM, the technique can provide continuous information over large regions. In this way, many soil properties such as soil texture, available water capacity, soil depth, acidity or alkalinity etc. that are crucial to support agricultural practices and soil protection measures can be mapped from a limited amount of information in a rapid and detailed manner.
As well as being much cheaper, speaker Alfred Hartemink of World Soil Information highlighted Digital Soil Mapping's capability to produce new and critical information. Using advanced modelling tools, for example, the Joint Research Centre has developed procedures to assess the amount of biomass (living material) in the soil at a resolution of 100 metres. Biomass is a measure of the driving force behind the soil food chain and is a parameter not normally collected during traditional soil survey techniques.
"Soil performs a multitude of environmental, economic, social and cultural functions and thus plays a vital role in sustaining life, supporting global environmental systems and conserving biodiversity. In some soils, more than 5 tonnes of animal life can live in one hectare of soil. The sustainable management of soil is fundamental for the development of a stable agricultural system, for reducing famine and combating land degradation," said speaker Alex McBratney of Sydney University.

http://www.globalsoilmap.net