Indicators in the study sites

Table of Contents

1. Compilers and contributors
2. Introduction
3. Climate indicators
4. Water indicators
5. Soil indicators
6. Vegetation indicators
7. Water runoff indicators
8. Forest fires indicators
9. Agriculture indicators
10. Cultivation indicators
    1. Tillage operations
    2. Frequency of tillage
    3. Tillage depth
    4. Tillage direction
    5. Mechanization index
11. Animal husbandry indicators
12. Land management indicators
13. Land use indicators
14. Water use indicators
15. Tourism indicators
16. Human characteristics indicators
17. Institutional indicators
18. Conclusions
19. References

Cultivation indicators

In the last decades soil management has changed dramatically by introducing new land cultivation implements and especially the tractor. The availability of heavy powerful machinery favored deep soil plowing and high speeds in directions usually perpendicular to the contour lines. This resulted in the displacement of huge amounts of soil materials from the upper convex parts (summit, shoulder, back slope) of a hill slope to the concave parts (footslope, toeslope) and decreased significantly the production of the various crops. Such cultivation practices have greatly contributed to deterioration of soil quality for plant growth due to tillage erosion. Tillage erosion affects soil quality for long terms, by changing soil depth and consequently water holding capacity, nutrient availability, organic matter content, and crop yield. The effects of soil erosion on productivity depend largely on the thickness and quality of the topsoil and on the nature of the subsoil. Productivity of deep soils with thick topsoil and excellent subsoil properties may be virtually unaffected by erosion. However, most hilly soils are shallow or have some undesirable properties in the subsoil such as petrocalcic horizon, or bedrock that adversely affects yields. In either case, productivity will decrease as the topsoil gets thinner and undesirable subsoil is mixed into the Ap-horizon by tillage, or as water-storage capacity and effective rooting depth are decreased. Important indicators considered in this project for assessing land degradation and desertification risk are the following: (a) tillage operations, (b) tillage depth, (c) tillage direction, and (d) mechanization index (Table 8).

Table 8. Number of field sites in which indicators related to cultivation was recorded in the filled questionnaires