productivity and thus sustainability and development issues such as food security, nutritional quality, poverty reduction and overall development toward improved livelihoods (Steiner, 1996; Scherr, 1999; Penning de Vries et al., 2003). Furthermore, adequate soil management offers considerable opportunity for increased carbon sequestration, which may in turn mitigate climatic changes and their adverse effects on agricultural production and resource degradation.

Causes of soil and land degradation are closely related to numerous socioeconomic factors such as population growth and changing consumer habits; unprofitable farming due to low yields, high input cost, low farm-gate prices, and lack of access to markets; high risk, discouraging investment; and insecure land tenure and user rights (Studer et al., 2000). It has become apparent that AKST has to put more emphasis on tackling the reasons behind soil and land degradation, as well as developing and disseminating sustainable landmanagement practices that fit specific conditions.

Interventions to avoid, reduce and reverse soil and land degradation are required at different levels, and have to be coordinated and synchronized (Steiner, 1996). Most obvious are interventions at the plot or field level. Numerous practices and technological options fostering sustainable land management are available through both traditional and modern knowledge. However, options such as cover cropping, terracing, green manuring, conservation tillage and rotations with leguminous crops have to be adapted to the specific agroecological and socioeconomic conditions of the farm enterprises. This requires trial and evaluation methods that can be extrapolated to other locations. Modeling approaches supply information more rapidly than field trials and are considerably less costly. Further, various case scenarios may be simulated and explored, and results may be upscaled or transferred to other environments, particularly if modeling is combined with GIS or remote sensing. However, modeling approaches require a solid database, which in many countries of the region is not yet established.

A major problem with regard to sustainable land management is that the profitability of particular measures is often low or not directly obvious, especially in view of such continuously rising opportunity costs as labor. Technology development has therefore to focus on satisfying the shortterm economic interest of farmers and households. Focus on promoting sustainable land use will thus have to shift to increasing productivity by maintaining, improving and stabilizing yields rather than on conserving soils (Scherr, 1999). Furthermore, technologies introduced will have to be compatible with the farmer’s farming system and riskavoidance strategy. Risk reduction is a particular primary concern for smallholder farming in the adverse environments of CWANA dry areas. Thus farmers may find quite acceptable recommendations that do not necessarily improve profitability but promise greater yield security and stability (Steiner, 1996)

For many interventions focusing on soil and land management a community or watershed approach will be necessary. Land-use planning, possibly coupled with changes in land tenure, zoning rules, control of agricultural land conversion and management of common lands, involves issues that are typically dealt with at this level (Scherr, 1999). Particularly in marginal lands, spatial concentration and

intensification of production should be encouraged to achieve more profitable production and simultaneously protect fragile land from degradation (Scherr, 1999). Improving present land use and identifying alternatives to inappropriate land use have to be negotiated in a multilevel stakeholder approach, in which it is important to integrate local authorities and national administrations (Hurni et al., 1996). Participatory approaches and the formation of farmer or land-user associations, village committees or cooperatives may facilitate mutual understanding and collective action (Steiner, 1996; Penning de Vries et al., 2003).

At the national level, policies and legislation relating to socioeconomic issues and institutional aspects regarding agricultural research and extension will play a major role for achieving more sustainable soil and land management. Flanking measures to reduce the demographic pressure of high population growth rates may relieve pressure on land (Steiner, 1996). Generating nonagricultural employment opportunities, agricultural opportunities in other areas and opportunities in forest management (Scherr, 1999) may contribute to increased income in rural areas. This change for the better should in turn favor investments in agriculture, often facilitating measures and practices for more sustainable land use. Developing credit and savings schemes may help farmers organize and finance investments in land improvements and conservation.

The effects of pricing policies regarding inputs and outputs as influenced by market liberalization and protective measures, tariffs and taxes, or other incentives and charges may vary in different countries. Higher producer prices often stimulate investment in agriculture and may thus lead to increased productivity and more sustainable land management. Ensuring market access for farmers is a prerequisite for pricing policies to produce impact, often requiring infrastructure development. Internalizing such external effects of land degradation as off-site costs of erosion (Steiner, 1996; Penning de Vries et al., 2003) and recognizing the multifunctionality of agriculture may assist in appropriate pricing policies.

Land tenure legislation must guarantee long-term landuse rights to owners and leaseholders if land users are expected to invest in long-term soil conservation measures. However, often such rules need to be tailored to such local conditions as traditional land rights and the interests of different stakeholders. Local institutions are generally in a better position to adapt and enforce such regulations than national entities. The value of land is an essential component of land law because it greatly determines the commitment of land users to use this production factor in a sustainable way (Steiner, 1996).

Another important domain of national policy relates to agricultural research and extension. To assume their task of solving the problems of land users, researchers and extension agents require a clear definition of target groups and recommendation domains, and precise information on the decision-making criteria of land users, who often apply decision-making measures other than those specialists use. Participatory technology development may foster the adoption of interventions (Steiner, 1996); improve integration of research, technology development and extension; and facilitate learning from and disseminating results of successful