Soil Erosion Management Practices in the Prefecture of Kilkis, Northern Greece

摘要

Declining yield, as a result of erosion in soils located in the Prefecture of Kilkis, Northern Greece has been observed. An area of about 3.000 hectares has been studied and the majority of the examined soils were mainly formed from the weathering of limestone or acidic material. These soils cover mainly hilly areas, have been classified as Entisols, Inceptisols or Alfisols, and are usually cultivated by wheat, maize, cotton, tobacco and sugar beets. They have been developed on tertiary or quaternary deposits and the upper terraces or alluvial fun are very susceptible to erosion. The appearance of high degree of erosion is present in the slopes greater than 6 % and is illustrated in the erosion map. Pronounced differences on soil depth, texture, water holding capacity, and nutrients have been recorded. Available phosphorus was very low in the subsurface layers, whilst potassium ranges in the ploughing layers and magnesium was in normal levels. Nutrient loss is quite severe and nitrogen leaching seems to play a dominant role in the decline of the crop yield, hence on farmers income. Attention should be paid hi the water shortage during the dry season, which affect land cover and erosion risk is increased during the rainy season, hi particular, it can be argued that in this semi-arid region the following measures and practices may be adopted such as: the policy of subsidies which encourage farmers for rotation or set aside of marginal areas, incentives for reforestation, minimum ploughing and/or ploughing along contour-lines, rational irrigation by means of the extension of drip irrigation systems may be applied, avoidance the burning of plant residues after harvesting and hi general adoption of a sustainable land use planning may be introduced.