Optimisation of field machinery for an arable farm converting to organic farming

Optimal crop and machinery systems are essential if organic farming is to be economically competitive. The aim of this study was to examine how the capacity of an optimal field machinery system is affected with respect to economy when a farm converts to organic production. An important part of the work was to calculate timeliness factors valid for organic farming. A case study was made for a typical arable farm in the south-central part of Sweden. To keep the scope manageable, the focus was on two of the most important machines used; the seed drill and the combine harvester. Machinery costs consist of three parts: direct machine costs, labour costs and timeliness costs. For optimisation of farm machinery systems, a method based on linear programming was used. The optimal size of the seed drill and combine harvester increased when the arable farm in this study converted to organic production. The total machine costs were 7% higher in conventional production but calculated per kg grain produced the machine costs were 58% higher in organic production. The main differences in timeliness costs between organic and conventional farming can be attributed to two counteracting facts: the lower yields and the higher product prices in organic farming. Timeliness cost per kg cereal produced was higher in organic production.