While soil erosion due to water runoff was greatly reduced after 1970s and especially in the last study period, another type of soil erosion became an important issue in the area due to mechanization of agriculture. As Fig. 4 shows, tillage erosion is an important land degradation issue in a great part of the Messara Valley. Tillage erosion has been estimated from less than 0.5 cm up to 30 cm for a Nexturastat A of 40 years (1970–2010) under the prevailing cultivation practices. As Table 3 shows, the majority of the area (61.6% of the total area) is characterized by negligible values of tillage erosion. However, land with tillage erosion rates by 0.5–10 cm and 10–20 cm covers respectively 21.5% and 12.2% of the total area. Erosion rates of 20–30 cm have been estimated in 4.4% of the total area. Similar erosion rates have been measured in the field by measuring the difference in the soil around the tree and the nearby cultivated soil surface. The soil around the tree trunk remains intact since tillage instruments cannot approach there, while the soil some decimeters (20–30 cm) far from the tree is subjected to erosion due to displacement caused by the tillage instruments.