A MULTI-GOAL MATHEMATICAL APPROACH FOR THE OPTIMIZATION OF CROP PLANNING ON ORGANIC FARMS: A SLOVENIAN CASE STUDY

A combination of linear and weighted goal programming for crop rotation planning has been used in developing a tool/model for solving several management goals simultaneously. The model was implicated for the case of organic farming in Slovenia. The results yielded reasonably accurate information regarding different economic parameters and nitrogen off-take from calculated crop rotation. The model was tested in four different scenarios with the influence of various goals weighting the results. From the obtained results, it is obvious that a combination of weighted goal programming and linear programming gives rise to a better solution from an economic perspective (i.e. higher total income per crop rotation and lower costs per crop rotation). It also provides a better solution for diversified and economically feasible crops for inclusion in crop rotation compared with the situation when farmers use only a linear mathematical technique. An investigation of the results showed that the model does not prefer mono-crop production strategies, which represent crucial drawbacks for organic agriculture, such as soil depletion, diseases and pests outbreak and soil degradation. The developed model can help farmers to obtain answers regarding four main issues in crop rotation planning; i) cropping strategy, ii) potential hiring of extra resources, iii) quantity of harvested crops and iv) quantity of fertilizer being saved in the second year of planning.