Soil in Atsbi Wenberta
The soils of the Atsbi Wenberta woreda (district) in Tigray (Ethiopia) reflect its longstanding agricultural history, highly seasonal rainfall regime and relatively low temperatures. The northern part of the district is on the high uplifted Atsbi Horst (with metamorphic rock and consolidated Palaeozoic fluvio-glacial deposits) , whereas the southern part is dominated by the Des’a forest on Antalo Limestone. In between there is the fluvial landscape of Hayqi Meshal. Particularities in the southern part of the district are soil catenas on intervening plains behind tufa dams and in a polje. Factors contributing to soil diversity. Climate . Annual rainfall depth is very variable with an average of around 800 mm. Most rains fall during the main rainy season, which typically extends from June to September. Mean temperature in woreda town Atsbi is 17 °C, oscillating between average daily minimum of 9.4 °C and maximum of 24.3 °C. The contrasts between day and night air temperatures are much larger than seasonal contrasts. Geology. The following geological formations are present in the southern part: On the northern Atsbi Horst: Topography. As part of the Ethiopian highlands the land has undergone a rapid tectonic uplift, leading the  occurrence of plateaus, valleys and gorges. Land use. Generally speaking the level lands and intermediate slopes are occupied by cropland, while there is rangeland and shrubs on the steeper slopes. Remnant forests occur around Orthodox Christian churches, in a few inaccessible places and especially in the Des’a forest. A recent trend is the widespread planting of eucalyptus trees. Environmental changes. Soil degradation in this district became important when humans started deforestation almost 5000 years ago. Depending on land use history, locations have been exposed in varying degrees to such land degradation. Geomorphic regions and soil units. Given the complex geology  and topography of the district, it has been organised into land systems - areas with specific and unique geomorphic and geological characteristics, characterised by a particular soil distribution along the soil catena. Soil types are classified in line with World Reference Base for Soil Resources and reference made to main characteristics that can be observed in the field. Soil erosion and conservation. The reduced soil protection by vegetation cover, combined with steep slopes and erosive rainfall has led to excessive soil erosion. Nutrients and organic matter were lost and soil depth was reduced. Hence, soil erosion is an important problem, which  results in low crop yields and biomass production. As a response to the strong degradation and thanks to the hard labour of many people in the villages, soil conservation has been carried out on a large scale since the 1980s and especially 1980s; this has curbed rates of soil loss. Measures include the construction of infiltration trenches, stone bunds, check dams, small reservoirs such as Addi Shihu and Era as well as a major biological measure: exclosures in order to allow forest regeneration. On the other hand, it remains difficult to convince farmers to carry out measures within the farmland  ("in situ" soil management), such as bed and furrows or zero grazing, as there is a fear for loss of income from the land. Such techniques are however very effective.