| dc.description.abstracteng | As part of the CRC 990: “Ecological and Socioeconomic Functions of Tropical Lowland Rainforest Transformation Systems (Sumatra, Indonesia)” of the University of Göttingen, this thesis is devoted to the subject of the technical and environmental efficiency of smallholder palm oil and rubber production. With this research, we hope to find opportunities to reconcile economically beneficial small-scale palm oil and rubber cultivation in Indonesia with sustainability and diminished degradation of ecosystem services. The challenge to this problem is twofold. Firstly, the economic superiority of the two main crops rubber and oil palm over the traditional crops fostered the expansion of cultivation areas towards zones with the most biologically diverse systems on this planet, such as primary forest. The loss of biodiversity and ecosystems functions and degradation of soils con- tribute to overall concerns of both monoculture productions. Secondly, due to increasing cultivation of the two main crops, the cultivation systems themselves exploit the limited resources on which they ultimately depend. These factors further increase climate change, wherefore augmenting the productivity of the two production systems without increasing input allocations, contributes to the challenge. We identify these potentials via efficiency analysis.
In three sections, this dissertation analyses the main transformation systems of oil palm and rubber to reveal the economic benefits, production determinants and the linked efficiencies of production. The analysis first focuses on the technical efficiency aimed at localizing sources of inefficiencies and possibilities to ameliorate the overall degree of efficient production by applying a stochastic frontier analysis. The latter showed that the historical development of the oil palm and rubber sector separated producers in autochthonous and transmigrated groups, leading to significant differences in their production techniques in the case of oil palm. Transmigrated producers, being the most efficient group, reflect the general tendency that security and support change the efficiency in both production systems.
The second analysis enhances the estimation introducing an environmental dimension to the estimation of efficiency in smallholder rubber production. This interaction between rubber production and the status of the environment or the surrounding ecosystem underlies a trade-off function, the shape of which determines the interdependency. The empirical results show that this trade-off function is determined by an outward bending curve, indicating an increase in the desired output and following an increase in the disturbed ecosystem, represented by the number of invasive plants. Next to the general shape, we quantify the overall efficiency levels and specific determinants of an efficient production by analysing the trade-off curve.
The third analysis focuses on the discussion of interdependence between oil palm and rubber production and environmental factors. For this purpose, we make use of a deterministic approach including a two-stage estimation of soil fertility parameters. The estimation revealed that the expansion of the cultivation area aggrandizes towards peat soil and that water-saturated mineral soils result in a higher inefficiency. Moreover, production efficiency is partly dependent on the soil parameters, indicating a possibility of alteration by fertilization. | de |