Evaluation of Soil Degradation in Conditions within the Czech Republic.
Borivoj Sarapatka1, Pavel Novak2, and Marek Bednar1. (1) Department of Ecology, Palacky University, tr. Svobody 26, Olomouc, 771 46, Czech Republic, (2) Research Institution of Ameliorations and Soil Conservation, Zabovreska str., Prague 5 - Zbraslav, 156 27, Czech Republic
At present throughout the whole world there is great concern for the sustainability of land use by man. A lot of evidence has been found to show that the soil quality is or may be worsening. Lal (1995) described the land resources of the world as finite, fragile and non-renewable and reported that only about 22 % of the total area on the globe is suitable for cultivation and only 3% has a high agricultural production capacity. A series of subsequent official reports (e.g. from UNO) warn of some degree of soil degradation threat. The production aspect alone does not suffice for complex evaluation of the soil. Wider ecological or environmental connections must be taken into account because the soil has, apart from its productivity, many other non-productive functions. Soil degradation has both global and regional impact. Farming methods contribute significantly (c. 30%) and in combination with over-grazing, which is also agricultural activity, the rate exceeds 60%. According to Oldeman (1994) water erosion is the predominant form of soil degradation (55.7%), followed by wind erosion (27.8 %), chemical (12.3 %) and physical damage. In Czech conditions the individual types of degradation differ in area, the most notable being water erosion which threatens more than 45% of agricultural areas. This is followed by wind erosion (11%), extreme soils – clay soils (4.5 %) and soils affected by dryness (1.5%). In our work we have evaluated available data on individual types of soil damage, which has been processed in the Czech Republic in recent decades (most of the background information came from the database of the Research Institute of Ameliorations and Soil Conservation in Prague and from the Central Institute for Supervising and Testing in Agriculture in Brno). Individual types of degradations (water erosion, wind erosion, soil compaction, extreme soils (clayey soils), loss of organic matter, acidification, dryness impact and intoxication) were classified in one of three groups: physical degradation, desertification and chemical degradation. Maps of individual areas of degradation were processed by overlay and assigning weight techniques in ArcView Spatial Analyst GIS environment to create final maps for each class of degradation threat. The same technique was used to create a final map showing the most troubled areas in the Czech Republic, threatened by soil damage. The level of degradation could be reduced by soil protection management which is connected with landscape protection in environmental protection areas. For this reason we have included this aspect in the calculations, too. From the results we see that most problems are in very intensively used agricultural production areas, which are not included in less favored areas (LFA). These are often soils with signs of desertification (areas affected by dryness, water erosion and loss of humus). From this evaluation a document for decision making at ministerial level is currently being processed. It should ensure more environmental thriftiness of farming systems together with protection of soil quality in the affected production areas. In the conference submission a system of soil-degradation evaluation in Czech conditions will be introduced and then, in GIS environment, the resulting degradation maps will be presented. These will serve both for further investigation in affected areas and for optimization of land use.