Optimising the integration of crop and dairy production systems in the Netherlands

Renewed coupling of crop and dairy production systems is seen as a potential pathway towards more environmentally sustainable agricultural production, while it might also be an economically viable strategy. The integration of crop and dairy production can occur at the farm, but also at regional level. In the latter case specialised crop and dairy production systems cooperate to improve, for example, the cycling of nutrients across farms by exchanging land, feed and fertilizers. This can mitigate the use of external inputs and promoting the self-sufficiency of farms and regions. Integrated crop-dairy systems could contribute to the diversification of cropping systems with positive effects on various ecosystem services. Most studies analysed the environmental and economic impacts of integrated crop-dairy systems at field level, i.e. ley-arable systems, and did not address impacts at higher spatial scales. There is limited insight if the integrated crop-dairy systems can contribute to more human edible food with a net reduction of environmental impacts. The aim was to quantify and evaluate the environmental and economic benefits of integrated crop-dairy systems on typical sandy soils in the Netherlands, and to quantify the net contribution to food production. We developed an optimisation model which integrates a crop and dairy production system at regional level. The model will be used first to optimise both production systems separately. These outcomes are evaluated and used as a reference scenario. Different integration scenarios are tested, e.g. with and without land exchange or the use of only leftover streams for dairy cows. The impact on environmental (e.g. nitrogen and carbon footprint), economic (e.g. labour income) and food system indicators (e.g. human-edible protein conversion ratio) and farm configuration will be assessed. This study will show that the potential of integrated crop-dairy systems depends on the objective of optimisation and integration strategy