Closing nutrient cycles within organic farming
Organic agriculture aims at working according to natural cycles and with a balance between plant and animal production. This type of agriculture closes material cycles as much as possible. Organic agriculture in the Netherlands is highly specialized, with as main sectors dairy farming, pig farming, poultry farming, arable farming and outdoor horticulture. Connections between these sectors are very weak in terms of size or exchange of (by)products. This has led to unbalanced nutrient cycles at farm, regional and national level (Hofstad & Schröder, 2002; Prins, 2006). One of the questions is which and how much plant products and by-products should be made available within the Netherlands in order to feed the animal sector. And on the other hand; how much land is needed to supply enough nutrients from the animal sector to the plant production sector.
The aim of this study is to analyse the effects of a further closing of nutrient cycles in Dutch organic agriculture, based on the agronomic configuration of ‘complete’ organic production systems. The main focus is on the agricultural effects in terms of areas of the various sectors, land use within each sector, exchange of (by)products between sectors, productivity per ha and per animal, etc. under different scenarios related to the use of less favoured inputs from conventional agriculture or abroad. Economic aspects are only touched upon.
Modelling offers the opportunity to quantify organic agricultural systems in a transparent and consistent way. In this study we have developed a linear programming model to optimize the configuration of organic agricultural systems, given a set of constraints and selecting from a large number of ‘organic activities’. In this case the gross margin of the Dutch organic sector will be maximized.
A large amount of basic material is available.
Period: any time
Gerrie van de Ven 0317-482140 firstname.lastname@example.org
Bert Rijk 0317-480402 email@example.com