Dimensionless numbers for evaluating mechanization in agroforestry systems based on UN SDG indicators

No agricultural technology can be effective over time unless it is compatible with the natural processes and dynamics of a given agroclimatic region, otherwise, it ultimately becomes unsustainable. Agroforestry Systems (AFS) tend to follow the natural dynamics of forests, but the complexity of their management limits the use of these systems to the manual operational capacity of family farming, which translates into small cultivated areas and arduous labor. Based on the indicators of the Sustainable Development Goals (SDGs) of the United Nations (UN) and through the Dimensional Analysis method, this study sought to establish and test indicators to evaluate and compare the suitability of agricultural machines for AFS cultivated under family farming. Data were collected on three different agricultural machines used in AFS and on two different AFS arrangements, which were compared through the proposed method in order to generate analyses on the suitability of the different machines for the different arrangements. Five indicators were established: π1-energy efficiency; π2-dimensional adaptability; π3-operation over tree rows; π4-productive compaction; and π5-productive–ecological balance. The study demonstrated the effectiveness of the method and the proposed indicators for studying and evaluating the sustainable mechanization of AFS. The results proved that smaller machines are more suitable for use in AFS in the context of family farming. The costal brushcutter was responsible for the best results when compared with larger machines used in biodiverse and complex systems; however, operator labor-related parameters were not taken into account in this analysis.