Breaking the spiral of unsustainability : an exploratory land use study for Ansai, the Loess Plateau of China

Serious soil loss, food insecurity, population pressure, and low income of the rural population are interrelated, and consequently result in a spiral of unsustainability in the Loess Plateau, China. This thesis takes Ansai County in the Loess Plateau of China as a case study, to explore strategic land use options that may break the unsustainability spiral and meet goals of regional development. A systems analysis approach has been applied, in which fragmented and empirical information of the biophysical and agronomic conditions is integrated with well-adapted production ecological principles and other knowledge sources.With respect to the land use problems and regional development objectives, alternative production activities (systems) have been identified and quantified using a 'target-oriented approach' and the concept of 'best technical means', and based on information obtained from a quantitative land evaluation (based on the EPIC model), experimental data, literature and expert knowledge. Production activities have been quantified for cropping, fruit, grassland and firewood production systems, and animal husbandry. Production techniques emphasize soil conservation, productivity, use efficiency or low emission of chemicals. The quantified production activities, resource constraints, and socio-economic and environmental objectives have been incorporated into a multiple goal linear programming model that is used to optimize land use allocation, evaluate trade-offs among objectives and evaluate policy scenarios.The results reveal that the goals of food security and soil conservation in Ansai can be easily achieved from a biophysical and agro-technical point of view. Current slope cultivation and the resulting serious soil loss can be greatly reduced, while still guaranteeing food security for the rural population (in 2020). The soil loss control is, to a large extent, in line with the goals of increasing crop productivity and labor productivity (net agricultural return per laborer). In the long term, terracing and crop rotations with alfalfa could be the best options for soil conservation and also for agricultural production. The large rural labor force can be used for terrace construction. Alfalfa can fix nitrogen, and thus greatly reduce the demand for fertilizer N, and also improve soil fertility.The large rural population and the lack of off-farm employment opportunities could be the most important factor affecting rural development in Ansai. This is evident from the trade-off results, i.e., increasing the total employment in agriculture leads to an apparent adverse effect on many other objectives. However, there is a potential for maintaining high agricultural employment at a reasonable income level. The current low net return due to the very limited external inputs and poor crop and soil management can be substantially improved by efficient resource use and appropriate inputs.This research work contributes to the understanding of regional problems and agricultural development potentials. The results show agro-technical possibilities for breaking the spiral of unsustainability in this very fragile and poorly endowed region. Soil conservation, food security, employment and income for the rural population can be greatly enhanced by appropriate land use and agro-techniques. To promote actual development towards the identified options, appropriate policy measures aimed at improving the land tenure system and controlling population growth must be developed and implemented. The explored land use options enable a much more targeted policy development. In addition, the study can contribute to the formulation of a research agenda for research at field, crop and animal level.