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Die Wirksamkeit von Boden

Die Wirksamkeit von Boden

Literature review Swaify

Literature review Swaify 1997) and charcoal samples carbon dating indicated that forest burning began 2460 years ago. These indicate old history of forest burning and anthropogenic environmental influence. The old settlements and growing demand for wood and agricultural lands and traditional agriculture led to heavy deforestation and severe erosion in the area (Hurni 1987; Tekle 1999). The ill-suited agricultural practices such as up-and-down and repeated plowing facilitate severe erosion (Hurni 1987). Owing to high human population, the land-holding size is below the minimum (1 ha per household) and the livestock population (about 76 TLUs km -2 ) exceeds the carrying capacity of the land (Tekele 1999). For example, the population of South Wello grew at an annual rate of 3.37% between 1970 and 1994, and 1.43% between 1994 and 2007, i.e., the population was 1,174,600 in 1970, 2,123,803 in 1994 and 2,519,450 in 2007 (Tekle 1999; CSA 2008). Although agriculture is the major economic sector, it is still traditional (Ehret 1979; McCann 1995). The agriculture is largely based on cereal-livestock farming systems (ANRS-BFED, 2008) where they have complimentary and competitive effects to each other (Haileslassie et al. 2005). Farmlands used to supply crop residue as animal feed without putting manure back to farmlands while fallowing practices have been greatly reduced. These increased soilnutrient export out of the ecosystem, exacerbates the degradation processes and contributed to crop production loss (Omiti et al. 1999; Haileslassie et al. 2005). Due to the above numerous limitations and increasing demand for agricultural land, marginal lands have been converted to cultivation and grazing (Tekele 1999). As a result, agriculture in the region has been unable to provide sufficient food for its population. Thus, food insecurity remains persistent, which indicates the need for continued remedial measures (Bhan 1988; Dejene 1990; Tekle 1999). It has been reported that if the resources are not managed according to the potential, land degradation problems will remain cyclic (Bhan 1988; Tekle 1999). After the droughts, the Wello province received government attention, which led to the initiation of SWC measures (Dejene 1990; Tekle 1999). Consequently, research, capacity-building trainings and SWC projects were implemented. The SWC measures have been implemented on farmlands and communal lands. Farmlands received mainly terraces and check-dams. Communal lands are used for free livestock grazing and wood collection, and first mechanical structures such as hillside terraces, 20

Literature review micro-basins, cutoff drains and trenches were constructed, and then these lands were excluded from human and animal interference. The vegetation cover of these exclosures improved through enrichment tree plantation. However, the major concern in this regard is that the enrichment tree plantations are mainly covered by eucalyptus, while indigenous tree species have been significantly reduced (Eshatu 2004; Tekle 1999). The agriculture offices are responsible for overall coordination, monitoring, technical guidance and implementation of the program, while local and international NGOs support the program through finance, FFW commodities, logistics and project implementation (Herweg and Ludi 1999; Tekle 1999). 21