M.T.M.H. Lubbers

A discussion support model for a regional dairy-pasture system with an example from Réunion island

Reunion Island, situated in the Indian Ocean, presents a unique case study for modelling regional bio-economic parameters of the dairy industry. It is a good example of a closed system for several parameters of the model such as movement of animals, labour, consumption and available land. The existence of several agro-ecological zones from tropical to temperate, and various different types of terrain and vegetation presents another unique opportunity to study the impact of these features on the dairy industry. The present study models the dairy sector at a regional (island) level to study the impact of new or adapted agricultural policies in relation to changes in subsidy levels, price fluctuations and environmental policies (mainly nitrogen management). The model can be used to generate a number of scenarios to explore the effects of various policy measures, such as fixing the stocking rate according to EU norms, increasing or decreasing the milk subsidy, intensification (such as an increase in milk production to the allotted quota of 40 million litres/yr) and varying labour/price constraints (such as a reduction in labour hours or an increase or decrease in the milk price). The model is being utilized by the local dairy cooperative as a discussion support tool to study the implications at the regional scale of expanding the sector and assessing its economic, environmental and social impact

Modelling Nitrogen Balance for a Regional Scale Livestock-Pasture System as a Discussion Support Tool

Reunion Island is a French overseas territory in the Indian Ocean which provides a distinctive research opportunity to develop a regional bio-economic model for the dairy industry. The model aims to address questions related to social, economic and environmental priorities of the local dairy industry. Since Reunion is an island it is a natural closed system for various components of the models such as labour, dairy cattle, and land. The present study models the dairy sector at a regional (island) level, in close collaboration with key stakeholders, to study the impact of new agricultural policies in terms of changes to subsidy norms, price fluctuations and environment, with reference to nitrogen excess. The model generates a number of scenarios, to explore the effects of various industry controls on the environment (N excess), such as fixing the stocking rate according to EU norms, increasing or reducing the milk subsidy, intensification (such as an increase in milk production to 40 million litres per year) and labour and price constraints (such as an increase or reduction in the milk price or a reduction in labour hours). The model can be used to calculate N as an environmental indicator which is introduced by two sources (i) by way of fertiliser for fodder requirements and (ii) by the manure excreted by the dairy animals.