5 years ago

Die Wirksamkeit von Boden

Die Wirksamkeit von Boden

Implications of soil and

Implications of soil and water conservation measures for land rehabilitation- a synthesis 8.8 Overall implications of SWC for land restoration and livelihoods Land degradation is a result of the interactive effects of resource misuse and climate change. The anthropogenic effect can be reduced through minimizing the drivers (Asefa et al. 2003; Khater et al. 2003; Nyssen et al. 2009). The recurring droughts the country has faced have exacerbated the problem (Tilahun 2006). Drought deteriorates the land production potential, which results in resources over-utilization in order to fulfill the people´s basic needs (Oba et al. 2000; Angassa and Oba 2008). The conservation measures reduced soil and nutrient loss by water erosion. Even though considerable soil fertility gradients appeared in the earlier stage of terracing, the gradient reduced with the development of bench terraces (Sonneveld and Keyzer 2003; Dercon et al. 2003; Vancampenhout et al. 2006; Nyssen et al. 2007). Consequently, crop yield loss resulting from severe soil erosion was reduced (Chapter 6). The stable crop yield overtime indicates that terracing at least helped to maintain yields. The portion of the land used for terrace construction was not completely wasted, as this land is used for livestock feed production. In the crop-livestock system, the supplementary forage produced along the conservation structures can be regarded as a positive attribute. Before the conservation intervention, stream banks and gullies were encroaching on productive farmlands, but encroachment was remarkably reduced after the conservation measures (Chapter 4 and 5). The rehabilitated stream banks and gully sides are used for forage and wood production. The field observations and discussions with farmers also clearly showed that the structural and biological conservation measures reduced both in-site and offsite damage resulting from soil erosion and runoff (Chapter 4). Generally, SWC interventions played an important role in the reduction of erosion-induced land degradation and agricultural production loss. On the other hand, both the physical and biological SWC measures compete with land use. In the study area, farmers are facing livestock feed shortage in older exclosures, as the grass cover is replaced by higher layer vegetation. Farmers complained that they are facing feed shortages even for stall feeding, and complete exclusion of leaf-browsing animals like goats and camels forced them to destock these animals. Similarly, this and other similar studies showed considerable land reduction due to terracing. For example, in this study it was found that on average terraces occupy 130

Implications of soil and water conservation measures for land rehabilitation- a synthesis 6% of cultivable land, while Herweg and Ludi (1999) reported that terraces occupy 10 to 15% of the land. The population growth rate is double that of agricultural production, which indicates the necessity of solutions in order to optimize the demand and supply. It is obvious that land has to be managed properly, otherwise sustainable production will be threatened. This calls for careful planning, since the livelihoods largely depend on agriculture. In this regard, the possible options could be implementation of supplementary livelihood options, especially for the young people who do not have farmland. Moreover, implementation of strategic land-use planning is equally important. It should consider allocation of parts of the exclosure for forage development and other uses. Physical SWC structures like bunds, terraces and check dams can also be used to produce forage grasses and trees. Terraces in the Maybar watershed are a good example, where grasses grown on the terraces are used as hay sources. Rehabilitated gullies and stream banks could also be used for forage production through the cut-and-carry system. Generally, SWC in general has positive impacts on agricultural production, nevertheless implementation of alternative livelihood options is most important in order to lessen the potential pressure on the land. 131

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