Comparing specialised and mixed farming systems in the clay areas of the Netherlands under future policy scenarios: an optimisation approach

Keywords: interdisciplinary analysis, mixed farming, linear programming, agricultural policy, environmental policyIncreasing attention for the sustainability concept also caused renewed interest in mixed farming systems in the Netherlands, which supposedly have some advantages over specialised farming systems. These advantages are not unambiguous and may also be realised in specialised farming systems. A systematic quantification of differences in environmental and economic performance between specialised and mixed farming systems was therefore considered useful. The multiple goal linear programming model developed in this study optimises the configuration of regionally specialised or mixed farming systems, subject to a set of constraints, to one of a set of defined objectives, selecting from a large set of agricultural activities. A second focal point of this thesis is agricultural policy analysis. With regard to these policies, numerous 'what if' questions can be posed. Such questions addressed in this thesis consider the optimal configuration of farming systems under Dutch manure policy regulations, the efficacy of these regulations in reducing emissions and the impact of reforms of the European Union's Common Agricultural Policy (CAP) on optimal configuration of farming systems.Model results suggest that economic performance of mixed farming systems is better than that of specialised farming systems. Differences in economic performance originate from agronomic-technical, organisational and institutional differences. Significant differences in environmental performance are absent.Dutch manure policy regulations still allow agricultural practices that are associated with relatively high leaching losses. It is proposed to implement additional, means-oriented policy instruments, specifically targeted to reducing leaching loss and incorporating financial incentives.Moderate CAP reforms as anticipated in Agenda 2000 are not likely to induce drastic changes in land use in the Netherlands other than resulting from autonomous developments. In contrast, a drastic reform - full liberalisation - is likely associated with considerable changes in agricultural land use. Farms will roughly be divided in two categories: large-scale, highly specialised farms and farms combining food production with contributions to other societal goals