Soil Survey and Monitoring in Cyprus

Transcription

1 Soil Survey and Monitoring in Cyprus Costas Hadjiparaskevas Department of Agriculture (Soil and Water Use Sector), Ministry of Agriculture, Natural Resources & Environment, CYPRUS, Introduction Cyprus is an island with an area of 9,251km 2. The topography includes two mountain ranges, one in the north and the other in the centre. Between them lies a plain. The cultivated area is estimated at 1,340km 2. The state forest land is 18% of the total area. The Status of Soil Mapping in Cyprus In Cyprus systematic soil studies and soil classification started in 1957, aimed at collecting information and data about the physical and chemical properties of soils. The first soil classification system used was based mainly upon the formation, origin and parent material of the soils. The first efforts to map the soils of Cyprus used topographical sheets at scale 1:5,000. The next step in soil mapping was the preparation of the General Soil Map of Cyprus at a scale of 1:200,000. The soil classification system adopted was based mainly upon the formation, origin and parent materials of the soils, as with the previous mapping. Accordingly, soils were classified mostly as Red, Sedentary and Alluvial or Colluvial soils. Usually an examination of the main horizons, A, B, C, D, together with soil physical and chemical analyses, was carried out in order to classify the soils of these groups into soil series identified by local names. Red soils In general, these have been classified into soil series according to the C and D horizons. Sedentary soils These soils were classified into soil series according to the type of parent material, which constituted the D horizon. Soil series have in many cases the same names as the geological formations. Alluvial or colluvial soils The classification is into soil series according to their origin and their physical and chemical properties. Local names have also been used for soil series. Later, in 1970, the FAO soil classification system was introduced. Through this system a new effort was undertaken to establish a common international language in soil classification. Based on our observations and soil studies the following diagnostic horizons from the FAO system have been adopted: Mollic, Ochric, Argillic, Natric, Cambic, Calcic and Gypsic. In order to separate soil units, some diagnostic properties from FAO (UNESCO) system were used and a number of soil orders and sub-orders recognised, corresponding to the following general definition: Lithosols Soils limited in depth by continuous coherent and hard rock within 10cm of the surface. Lithosols are divided into two sub-orders: Calcaric Eutric. Fluvisols Soils from recent alluvial deposits, having no diagnostic horizons other than an Ochric A or a histic H horizon. 97

2 Regosols Soils from unconsolidated material, having no diagnostic horizons other than an ochric A horizon. Regosols and Fluvisols have been divided into calcaric and eutric sub-rders. Rendzinas Soils having a mollic horizon, immediately overlying extremely calcareous material. Solonchaks Soils having high salinity within 125cm of the surface (EC > 15mmhos). Solonchaks have been separated into Gleyic and Orthic sub-orders. Solonetz Soils having a natric B-horizon. Vertisols These soils have 40 percent or more clay in all horizons, developing wide cracks from the soil surface downwards. Furthermore, they have slickensides and unfavourable physical properties. Cambisols These soils have a cambic B-horizon and no diagnostic horizon other than an ochric or an umbric A horizon, a calcic or a gypsic horizon. Soils classified into Cambisols occupy extensive areas and are subdivided into the following suborders: Vertic Calcaric Calcic Eutric Chromic. Luvisols These soils have an argillic B-horizon and they are subdivided into: Vertic Calcic Chromic. Land Use Classification A land use map of Cyprus showing classes of agriculture use and natural vegetation is shown in Figure 1. A land suitability classification map of Cyprus has also been prepared mainly for agricultural purposes. Its main objective is to classify the land according to its suitability for irrigation. New Soil Map The new soil map of Cyprus, printed in 2002 at scale 1:250,000 (Figure 2), is based on previous classifications and was adjusted to the new FAO classification system (WRB, 1998). During the last decades interest in soil surveys and mapping has been very limited due to the continuously diminishing contribution of the agricultural sector to the economy of the country - it is currently about 4% of the GNP. In areas where soils have not been surveyed, other methods have been used, such as extrapolation, photo interpretation and the general soil map of Cyprus. A number of important information sources have been used in the preparation of the new soil map of Cyprus: Geological Map of Cyprus, scale 1:250,000 Geological survey has been used to identify parent material of the soils. Other soil surveys Soil surveys, carried out in different areas of the country at different times, are the most useful pool of information. Many of these surveys were carried out by different soil scientists using in many cases different soil taxonomic systems. They were working on aerial-photos at scale 1:10,000 and preparing a soil map at scale 1:25,000. The main purpose of each soil survey project was to cover the most fertile soils and all the agricultural development areas. The majority of the existing soil maps were prepared mainly for agricultural purposes. For soil mapping and other relevant soil activities, the Soil and Water Section of the Department of Agriculture is the only government section responsible. Cyprus- cooperation In Cyprus there is no specific institution dealing with soils and because of this it is important to establish technical scientific cooperation with other international soil centres. The study of calcareous soils was carried out in cooperation with the Federal Institute for Geosciences and Natural Resources, Hanover, Germany. About 36% of the total area of Cyprus is categorised as having slightly to high calcareous soils. 98

3 Recent Work Using the newly secured data, a digital soil map of Cyprus has been prepared at scale 1:250,000 in collaboration with the remote sensing centre of the Ministry of Agriculture. An extension of this work has been preparation of a soil map of Cyprus at scale 1:1,000,000 based on the creation of soil associations of the main group of soils. Figure 2: Land use map of Cyprus: natural vegetation & agricultural use 99

4 Figure 2: Soil map of Cyprus 100

5 This map was prepared for inclusion in the European Soil Database. National and Regional Maps in a Global Context The problems envisaged in adapting the national and regional soil maps using the global methodology of soil taxonomy include: 1. Various soils occupying small areas, as remnants of erosion, were mapped as associated soil groups. Other soils developed in depressions and on slopes of mountainous areas were also mapped as associations. 2. In a general soil map at small scale (1:250,000 to 1:1,000,000), where generalisation is necessary, small areas with different soil groups are blended. As a result, detailed information about the physical and chemical properties of these soils may be obscured. Soil Monitoring Monitoring activities are concentrated on establishing Nitrate Vulnerable Zones (NVZ) as required by the EC Nitrate Directive. A map showing the NVZs at a scale of 1:250,000 is in the final stage of preparation. The next step will be to prepare a map showing the areas where sewage sludge can be applied. Suggestions The revised classification system of the FAO (WRB, 1998) seems to have improved the classification structures by the introduction of Soil Groups, Diagnostic Horizons, properties and materials. Using this terminology and coding, soils can be classified to a lower category level in an international system, which obviates the need to use local names of soil series names. Problems that occur by the use of different scales can be overcome through using digital mapping. Surveys can be carried out at different detailed scales without any difficulty in the eventual printing of any scale map. References FAO (1998). World References Base for Soil Resources. 101