Conservation agriculture Tanzania_casestudy.pdf - Sokoine ...

TemperatureTemperature decreases with increasing elevation by about 0.6 o C for every 100 m.Mean annual temperature ranges from 15 o C in Nov forest to 24 o C at the levelof Lake Eyasi. The coldest months are June–August, the warmest October–April.There are no frosts.WindsWind velocity is generally highest during rainy season storms (Meindertsman andKessler 1997). Wind moves from a high pressure belt (cold) in the high altitudeof Karatu landscapes to the low pressure belt (hot) of low altitude in Eyasi basin(COPEC 2003). This climatic process, affecting all of Karatu District, causes greatdamage—wind erodes the soil and dries out the vegetation.Natural resourcesAreas of the district are rich in natural resources. On the north, the district bordersNgorongoro Conservation Area Authority, and to the south-east Manyara NationalPark extending to Marangu Forest Reserve. On the western part of the district isa vast area surrounding Lake Eyasi extending to Matala, rich in wild animals thatattract tourists from all over the world.The district has facilitated and built the capacity of grassroots communities inmanaging natural resources and their products by replanting trees in open areas andon individual gardens, introducing bee-keeping and fishing as well as reserving openwildlife areas. The community carries out forest-enrichment tree planting in watersources and catchments areas, and on hilltops and abandoned lands. Common treespecies preferred and planted in Karatu include Gravillea robusta, Senna sp., Jacarandamimosofolia, Acacia codyla africana, Albizia spp. and Rauvolfi a spp. However, tree plantingand growth are threatened by uncontrolled grazing. There are also deliberate effortsgoing on to reserve open wildlife areas to attract hunting and tourism in the wilderness,and to reinstate wildlife migratory corridors.Practically all non-cropped areas have forest and grazing resources that are used forforestry, pastoralism and wildlife. Forest areas are located in the north-eastern partof the district. Dominating the study area are both bush and wooded grasslands,which occupy a large area of the central and southern zone adjacent to Lake Eyasi.Crops cover the higher altitudes of the north-east while grassland can be found insmall portions of the central zone.SoilsSoils vary depending on their origin and location. Shallow soils with low fertilityare found on summits and slopes. Clay soils of moderate fertility are found in thevalleys in gently rounded summits and on slopes overlying soft gneiss rocks.Of volcanic origin are the predominantly clay soils, some very shallow but veryfertile. Found in the Ngorongoro land system they include moderately steep foothillridges of volcanic cones, lava plains and foothill slopes. Soils with recent ash depositsare rich in salts and are highly erodible.62 Ringo et al.