WINFRIED E.H. BLUM
SOIL INDICATORS
FOR SUSTAINABLE LAND MANAGEMENT
University o f Natural Resources and Applied Life Sciences, Vienna
Sustainability comprises cultural, social, economic, environmental parameters and the dimension o f time. In a first approach, sustainability can be understood as a paradigm indicating the right direction, which helps us to steer our environmental, social and economic systems in such a way that future generations will not be harmed or have the same chances as we have today [Blum 1997; 1998a; 1999a,b; 2000b].
Adopting this approach for land management means that land management can only be sustainable if all the functions o f land and soil which are important for human societies and the environment can be fulfilled. This is still a very general and broad approach, which has to be adapted to the very specific local conditions in which we want to be sustainable. Therefore, being operational in sustainable land management means to look first into the different parameters which govern the local system. - In the context o f soil and land management, the first question will be: W hat are the main functions o f soil for human societies and the environment?
Under this aspect, six main functions can be distinguished, three o f them more ecological ones, the three others more socio-economic and technically oriented. Ecological functions o f soil are the biomass production in the form o f food, fodder and renewable material, through agriculture and forestry, in which land and soil serve as a basis for plant production.
Moreover, soils have important functions as mechanical filter, physico-chemical buffer and biological transformation substrate between the atmosphere, the geosphere, the hydrosphere and the biosphere, protecting ground water and drinking water as well as the food chain against pollution, and maintaining biodiversity.
Soils are the most important gene reserve on the globe, because they contain more species in number and biomass than all the biota above ground.
Those three ecological functions are endangered by the use o f land and soil as a physical basis for the development o f infrastructure for human societies, such as the construction o f houses, industrial premises, ways of transport, sporting grounds and dumping sites for refuse [Blum 1998b,с].
For this, soils are excavated and used as a source o f raw materials, furnishing clay, sand, gravel and other mineral and organic materials for construction and other human needs. - Finally, soils are a geogenic and cultural heritage, protecting archaeological and paleontological remnants o f great importance for the understanding o f the history ofhumankind.
Due to very severe competition in the use o f these different soil functions, three main forms o f competition can be distinguished:
The competition between soil as a physical basis and source o f raw material on one side and all ecological functions on the other side, because in the case o f the con struction o f a house or a road, all other ecological functions, including the function o f natural and cultural heritage are impeded. This is also true for the excavation of raw materials, because the remaining land surface does not allow to fulfil the three ecological functions any more.
The second form o f competition derives from the established infrastructure, such as traffic routes, settlements and industrial sites, which are causing severe loads on the adjacent agricultural and forest land and soils through the atmospheric pathway, e.g. through the deposition of pollutants and contaminants, on the waterway, e.g. through contaminated water, e.g. waste water, sewage sludge, or through terrestrial transport, when we contaminate and pollute soils through waste deposits and the incorrect use o f pesticides and fertilisers.
Finally, there exists also competition between the ecological functions themselves, be cause the optimisation o f agricultural production through the use o f pesticides and fertilisers may harm the quality of ground water through contamination, because each drop of rain falling on agricultural and forest land has to pass the soil before it becomes ground water and therefore in many parts of the world severe competition exists between the agricultural use o f fertilisers and pesticides on one side and the protection of ground and drinking water resources on the other side.
Further problems exist between intensive agricultural land use and biodiversity in many ways.
The spatial and temporal competition in the use o f these six different functions is widespread and leads to the question how sustainable land and soil use can be defined.
Sustainable land and soil use is the spatial and/or temporal harmonisation in the use o f all six functions, avoiding or minimising irreversible ones, such as sealing, excavation, salinisation, deep reaching compaction, severe contamination by inorganic pollutants and others.
This is not a scientific but a political task, because scientists can only develop scenarios, explaining what may happen under which circumstances, when different decisions are taken. The decisions have to be taken in a bottom-up approach, when people o f a certain region define what kind o f land use they want or in a top-down approach, when leading people are deciding what they want and decisions are taken top-down.
In all these cases, either the local population on one side or the politicians and decision makers on the other side need information in order to take decisions.
Indicators are a condensed form o f information, which can serve for both sides, the stakeholders as well as the decision makers and politicians. This leads to a new way of steering soil and land management [Blum 1999c, 2000a,b,с]. Indicators, in this case soil indicators, can be used on different levels: firstly indicators help to define the state o f a certain land or soil. Indicators can also help to explain why this state exists, and therefore answer the question, what driving forces exist behind and what the pressures are, deriving from these driving forces?
On the other side, the question will arise, which impact the actual state o f soil may cause? There can be direct impacts or indirect impacts, negative and positive ones. The population as well as decision makers and politicians will then ask what they can do in order to change the system into a sustainable direction, and this means which responses can be given in order to avoid or to mitigate problems or to improve land and soil management?
For this purpose, the DPSIR framework approach was developed, based on the OECD Agri-Environmental Indicator Framework, defined by state, impact and response [OECD 1997].
The new DPSIR indicator framework developed by the European Environment Agency [1999] comprises driving forces, pressures, state, impacts and responses, and is shown in Figure 1. From this figure it becomes clear that soil indicators are most important tools to steer sustainable land management.
Based on Figure 1, the following example can be given.
The state of a soil can be characterised by degradation caused through contamination. The direct impact will be the inhibition o f any agricultural use. The indirect impact can be a change in the local population, in size and distribution, because without agriculture, many farmers have to move away in order to find new ways o f living.
On the other side, the question is, why is the soil contaminated? And here we may find emissions to air, water and land as a direct pressure, and the driving force behind can be, as in most cases, industrial or household activities, leading to emissions to the air, water or land and soil.
E m is s io n to air, w a t e r a n d land
U rban e x p a n s io n (s o il s e a lin g ) In fra stru ctu re
C o n s tr u c tio n D e -fo r e s ta tio n F o r e s t fir e s N u tr ie n t m in in g S O IL D E G R A D A T IO N L o ca l a n d d iffu se c o n ta m in a tio n S o il a cid ifica tio n
S a lin isa tio n
N u tn e n t load (s o il eu tr o p h ica tio n ) or N u tr ie n t d e p le tio n P h y s ic a l d e g r a d a tio n B io lo g ic a l d e g r a d a tio n S E C O N D A R Y P R O T E C T IO N R e fo r m of agricultural p r o g r a m m e s
S p e c ific re g u la tio n s o r d ir e c tiv e s
IN D IR E C T (E ff e c t s o n o th e r m e d ia ) C h a n g e s in p o p u la tio n s i z e a n d d istribu tion , L o s s o f b io d iv er sity , C lim a te c h a n g e , W a te r s t r e s s S O IL L O S S S o il S e a lin g S o il e r o s io n L a rg e s c a l e land m o v e m e n t s D IR E C T ( C h a n g e s in so il fu n c tio n s ) H u m a n p o p u la tio n L a n d d e v e lo p m e n t T o u r is m A gricultural p ro d u c tio n T r a n s p o r t I n d u stry /E n e rg y M ining N atural e v e n t s C lim a te c h a n g e W a te r s t r e s s PR IM A R Y P R O T E C T IO N D e s e r tific a tio n C o n v en tio n D e v e lo p m e n t of a n a tio n a l/ re g io n a l soil p ro te ctio n p o lic y
FIGURE 2. Land and soil management - the dimensions of space and time
The next question o f the local population, politicians or decision makers will be, how to mitigate this problem. There are many ways, reaching from information, education, capacity building, to specific regulations or legal instruments, avoiding e.g. industrial emissions to air, water and land, thus mitigating soil contamination or to remediate contaminated soils in order to allow again agricultural use [Blum 2001 a,b; 2002a,b].
From this example it becomes clear that the DPSIR framework approach is a very important tool to steer or to regulate sustainable land and soil use and to bridge between scientific and technical knowledge on one side and those who need this information for operational measures on the other side, such as farmers, foresters, land use planners, civil servants, politicians and decision makers.
However, Figure 2 reveals that this is not always an easy task, because land and soil management has different dimensions in space and time, e.g. looking into the effect of globalisation (Blum 2002c).
Figure 2 explains that there are several spatial dimensions, the world dimension, the country or regional dimension and the local dimension e.g. o f a farm or household, and that between all three levels, cultural, social and economic driving forces as well as ecological ones are influencing each other. Definitions and decisions which are taken at the WTO or at the EU level are certainly influencing on a country or regional level and are also influencing the farm or household level. The same is true for ecological driving forces, such as climate change, change in biodiversity and others.
Concluding, it can be stated that soil indicators are an important tool for sustainable land management on a local, regional and world wide level. Therefore, the actual endeavours for a European Soil Thematic Strategy by the European Community are based on this approach [Blum 2003a,b]. This Soil Thematic Strategy, distinguishing between 8 main threats to soil and its operational programmes aim at new directives for sustainable land and soil use in Europe, based on an indicator approach.
LITERATURE
BLUM W.E.H.1997: Sustainable land use and agro-ecosystem health.- 4th Intern.Conf. o f the East and Southeast Asia Federation o f Soil Societies on „Soil Q uality M anagem ent and Agro-Ecosystem Health”, Nov. 11-14 1997, Cheju, Rep. o f Korea-Supplemental Volume, pp. 51-68.
BLUM, W.E.H. 1998a: Agriculture in a sustainable environment - a holistic approach .Int.A gro-
physics 12: 13-24.
BLUM W.E.H. 1998b: Soil Degradation Caused by Industrialization and Urbanization. In: Blume H.-R, H. Eger, E. Fleischhauer, A. Hebel, C. Reij, K.G. Steiner (Eds.): Towards Sustainable Land Use, Vol. I, 755-766, Advances in Geoecology 31, Catena Verlag, Reiskirchen. BLUM W.E.H. 1998c: Soil Functions and Key Impacts on Soil - an Overview. In: Environmental
Policy - Soil Protection Policies within the European Union, 63-78, Workshop Proceedings 9 - 11 December 1998, Bonn/Germany, Federal Ministry for the Environment, Nature Conserva tion and Nuclear Safety, Germany.
BLUM W.E.H. 1999a: Policies for Sustainable Land Management. - Programme and Abstracts, pp. 52-54, Second International Conference on Land Degradation, 2 5 - 29 January 1999, Khon Kaen/Thailand.
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BLUM W.E.H. 1999c: Agri-Environmental Indicators for Sustainable Land M anagement. In: 70 Years Georgian State Agrarian University, pp. 18-27, Tbilisi, Georgia.
BLUM W.E.H.2000a: Soil Quality Indicators Based on Soil Functions (Extended Abstract). - ESSC - 3rd Iintem. Congr. „Man and Soil at the Third M illennium”, Valencia, 28.3.-1.4.2000 - Key Notes, pp. 127-129, Valencia.
BLUM W. E. H.2000b: W hat is sustainable land use? Paradigms versus indicators. - Internatio nal Symposium on Sustainable Land Management, Kuala Lumpur/ Malaysia, August 8-10, 2000, Abstracts, pp. 8-11, M alaysia Society o f Soil Science, Kuala Lumpur.
BLUM W. E. H.2000c: Definition o f Agri-Environmental Indicators. - Proceedings o f the Sympo sium Agricultural Environment Protection, Vol. 1, 11-15, Editura Helicon, Timisoara, Rumania. BLUM W.E.H.2001a: Environmental protection through sustainable soil management, a holistic approach. - Key notes, International Conference “Sustainable Soil M anagement for Environ m ental Protection Soil Physical Aspects, Florence/Italy, 2 -7 July 2001, pp. 1-9, Istituto Sperimentale per lo Studio e la Difesa del Suolo, Florence/Italy.
BLUM W.E.H.2001b: Using the soil DPSIR framework - driving forces, pressures, state, impacts, and responses - for evaluating land degradation (Box 1.1 ) in: E. M. Bridges, I.D. Hannam, L.R. Oldeman, F.W.T. Penning de Vries, S.J. Scherr, S. Sombatpanit (eds): Response to Land D egra dation, pp. 4 -5 , O xford & IBH Publishing Co. Pvt. Ltd. New Delhi, Calcutta, (ISBN: 81-204- 1494-2).
BLUM W.E.H.2002a: Soil quality indicators based on soil functions. In: Rubio J. L., R.P.C. M or gan, S. Asins, V. A ndreu (Eds.): Man and Soil at the Third Millennium, Vol. I, 149-152, G eo forma Ediciones, Logrońo, Spain, (ISBN: 84-7779-46-8).
BLUM W.E.H.2002b: Environmental Protection through Sustainable Soil Management, a H oli stic Approach. - In M. Pagliai and R. Jones (Eds.): Sustainable Land M anagement - Envi ronm ental P rotection - A Soil Physical A pproach. - A dvances in G eoecology 35: 1-8. Catena Verlag GmbH.
BLUM W.E.H.2002c: The role o f soils in sustaining society and the environment: realities and challenges for the 21 century. 17 World Congress o f Soil Science, 14-21 August 2002, Bangkok/Thailand. - Keynote Lectures, pp. 66-86. IUSS.
BLUM W.E.H.2003a: Sustainable Land and Soil M anagement in the European Union. In: Proce edings o f the 4 European Congress on Regional Geoscientific Cartography and Inform a tion Systems, 17-20 June, 2003, Bologna/Italy, Volume I, p. 121, Bologna.
BLUM W.E.H.2003b: Soil protection through sustainable land management - a holistic appro ach. -A n n a ls o f Agrarian Science, 1: 23-27 (ISSN 1512-1887), Tbilisi/Georgia .
EUROPEAN ENVIRONMENT AGENCY (EEA) 1999: Environment in the European Union at the Turn o f the Century. European Environment Agency, Copenhagen, Denmark.
OECD 1997: Environmental Indicators for Agriculture. Publications Service Paris, France.
prof. d r W infried E. H. Blum
