Farm-SAFE: The process of developing a plot- and farm-scale model of arable,forestry, and silvoarable economics

Financial feasibility and financial return are two key issues that farmers andland owners consider when deciding between alternative land uses such as arablefarming, forestry and agroforestry. Moreover regional variations in yields,prices and government grants mean that the relative revenue and cost of suchsystems can vary substantially within Europe. To aid our understanding of thesevariations, the European Commission sponsored a research project called“Silvoarable Agroforestry For Europe” (SAFE). This paper describes the processof developing a new economic model within that project. The initial stagesincluded establishing criteria for the model with end-users and reviewing theliterature and existing models. This indicated that the economic model needed toallow comparison of arable farming, forestry and agroforestry systems at a plot-and a farm-scale. The form of comparisons included net margins, net presentvalues, infinite net present values, equivalent annual values, and labourrequirements. It was decided that the model would operate in a spreadsheetformat, and the effect of phased planting patterns would be included at a farm-scale. Following initial development, additional user feedback led to a finalchoice on a model name, a final method of collating input data, and theinclusion of field-based operations such as varying the cropped area, replacingdead trees, and pruning. In addition options in terms of improved graphicaloutputs and the ability to undertake sensitivity analysis were developed. Someof the key lessons learnt include the need to establish clear model criteria andthe benefits of developing a working prototype at an early stage to gain user-feedb