Experience with fertilizer expert systems for balanced fertilizer recommendations

To evaluate soil fertility and to calculate fertilizer recommendations for different soil types and crop rotations, two expert systems were developed and are being used in Belgium and the Northern part of France. The BEMEX expert system (BEMEX, coming from BEMEstingsEXpertsysteem, Dutch for fertilization expert system) calculates field specific fertilizer recommendations for macronutrients and liming recommendations for crop rotations with arable crops and vegetable crops and for grasslands. The N-INDEX method is a field specific advice-system for N-fertilizer recommendation for most arable and vegetable crops. The knowledge base of BEMEX as well as of N-INDEX contains empirical and theoretical knowledge. The required information to run the expert systems consists of measurements of the chemical soil fertility on soil samples on the one hand and of information concerning the parcel and the crop on the other hand. The final output of the expert system is a two-to-five page bulletin, with the results of soil analysis and the fertilizer and liming recommendations. This bulletin is sent to the farmer. Additionally, an impressive database with soil fertility data is gathered annually. As a consequence presentation models such as choroplets, pie charts, etc. are useful tools to describe soil fertility on the basis of numerous soil analyses. Both the personalized advice bulletins and the general presentation models are the interface between the expert and the user of the expert system, which is commonly the farmer himself or extension staff members.