**3. Soil erosion and other exogenous processes**

As it was highlighted in the Land Code of Ukraine (art. 171), degraded lands are specifically those where erosion, landslides, karsts, floods, etc., are developed [9]. Ukraine's soil is prone to erosion, and over 30 million hectares (i.e. about half Ukraine's total territory) of land is strongly affected by erosion. Some agricultural practices, like planting of row crops (sugar beet, sunflower, etc.) in plantations, exacerbate the problem. Soil erosion is a significant problem which also decreases humus levels in soil.

Ukraine's relief and climate and its very high proportion of arable lands make erosion a widespread natural phenomenon. About a third of the arable lands are threatened by water and wind erosion. Poor land management practices, such as crop cultivation on steep slopes, excessive cutting of forests, shrubs and bushes, and overgrazing accelerate erosion. As a side effect, erosion is causing sedimentation in rivers, lakes and water reservoirs. As a result of erosion fertile soil is lost, plant nutrients are removed and there has been soil textural changes, deterioration of soil structure, declining land productive capacity, increased dissected fields, and increased streams and lakes pollution and pile ups on bottomlands, in stream channels, and in lakes and reservoirs. Over 500 million tons of soil is subjected to erosion processes annually leading to decrease of soil fertility. It is argued that with each dollar of added cost created by agricultural producers, one third is lost due to erosion [10]. The soil fertility decrease inevitably leads to increase in production cost. For the last 15 years, the intensity and frequency of droughts has significantly grown in the steppe zones of Ukraine. Droughts are observed to happen once in 3 years causing decrease of arable lands productivity. The climate change and expected extreme phenomena growth are supposed to exacerbate this tendency in the nearest future. Right in the steppe zone, the soil degradation processes are developed much harder than in the other parts of Ukraine. It is important to remember that a half of grain crops in the country are grown on the fertile chernozems in the steppe climate zone. In some south-east areas, the soils are degraded so heavily that additional donations are needed to restore their fertility.

The steppe zone occupies the southern part of Ukraine. It is spread from south-west to northeast up to 1100 km, and from north to south up to 500 km (**Figure 1**). Its total area is about 25 million hectares that makes up 40% of the whole territory of the country. The biggest steppe area is occupied under typical chernozems—10.4 million hectares. They are formed under grassland-fescue-feather vegetation in the northern part of the steppe zone. Because of the climate change, the humus layer thickness is gradually decreasing, and the typical chernozems are subdivided into medium-humic and low-humic chernozems of high (85–100 cm), medium (65–85 cm), and low (45–65 cm) thickness [11]. Agricultural activity promoted water and wind erosion spread. The wind erosion has covered more than 220,000 km2 so far and spread even in those areas where it has never been noticed before. For some time past, the dust storms of 8–17 h duration happened three to five times per year [12, 13]. The wind speed reached up to 20 m/s. It is known that the southern chernozems structure damage can occur when the wind speed is of 5–6 m/s [14]. With an exception of soil erosion phenomena, the UNCCD Country Profile of 2006 consider other exogenous geological processes caused land degradation in Ukraine (**Table 1**, UNCCD Country Profile, 2006) [3].


**Table 1.** Land degradation drivers in Ukraine.

ment of the land resources is 72.2%. And the steppe oblasts are characterized by the highest value of cultivated lands: Zaporizhia (88%), Kirovograd (86%), Dnepropetrovsk and Odessa oblasts (83% each), and Kherson (82%). A bit lower level is observed in the forest–steppe oblasts, and significantly lower level of cultivation (by 1.5–2 times) is within the Polissya territory. The percentage of cultivated lands in Ukraine is the highest in the world and the main contributors to that are the territories of forest–steppe and steppe zones [6]. For comparison: the percentage of tilled lands in the USA is 19%, France and Germany—33%, Italy—31% [7], that is these factors correspond to favourable and conditionally favourable characteristics. Such a high level of cultivated lands is unfavourable as from economic as well as from environmental points of view. It abruptly decreases a natural potential of the territory and

As it was highlighted in the Land Code of Ukraine (art. 171), degraded lands are specifically those where erosion, landslides, karsts, floods, etc., are developed [9]. Ukraine's soil is prone to erosion, and over 30 million hectares (i.e. about half Ukraine's total territory) of land is strongly affected by erosion. Some agricultural practices, like planting of row crops (sugar beet, sunflower, etc.) in plantations, exacerbate the problem. Soil erosion is a significant

Ukraine's relief and climate and its very high proportion of arable lands make erosion a widespread natural phenomenon. About a third of the arable lands are threatened by water and wind erosion. Poor land management practices, such as crop cultivation on steep slopes, excessive cutting of forests, shrubs and bushes, and overgrazing accelerate erosion. As a side effect, erosion is causing sedimentation in rivers, lakes and water reservoirs. As a result of erosion fertile soil is lost, plant nutrients are removed and there has been soil textural changes, deterioration of soil structure, declining land productive capacity, increased dissected fields, and increased streams and lakes pollution and pile ups on bottomlands, in stream channels, and in lakes and reservoirs. Over 500 million tons of soil is subjected to erosion processes annually leading to decrease of soil fertility. It is argued that with each dollar of added cost created by agricultural producers, one third is lost due to erosion [10]. The soil fertility decrease inevitably leads to increase in production cost. For the last 15 years, the intensity and frequency of droughts has significantly grown in the steppe zones of Ukraine. Droughts are observed to happen once in 3 years causing decrease of arable lands productivity. The climate change and expected extreme phenomena growth are supposed to exacerbate this tendency in the nearest future. Right in the steppe zone, the soil degradation processes are developed much harder than in the other parts of Ukraine. It is important to remember that a half of grain crops in the country are grown on the fertile chernozems in the steppe climate zone. In some south-east areas, the soils are degraded so heavily that additional donations are needed to restore their

The steppe zone occupies the southern part of Ukraine. It is spread from south-west to northeast up to 1100 km, and from north to south up to 500 km (**Figure 1**). Its total area is about 25

makes it monotonous, and economy activity—highly specialized [8].

**3. Soil erosion and other exogenous processes**

56 Land Degradation and Desertification - a Global Crisis

problem which also decreases humus levels in soil.

fertility.
