## 5 Conclusions  
Sustainability in agriculture is a complex concept and there are no common viewpoints among scientists about its dimension. Nonetheless, various parameters for measuring agricultural sustainability have been proposed, since the measure of the mere production capacity of an agro-system is not enough to evaluate it. This study clearly highlighted the relevance of considering different criteria, when we assess the advances in sustainability achievement that could be obtained introducing agro-ecological management practices and innovations. The findings also demonstrated that applying principles and practices which tend to follow the natural ecosystems can contribute to building up more complex agro-ecosystems, increasing resilience, and optimizing and maintaining biodiversity. In particular, the agro-ecological approach (ECO) both reduces the use of and dependency on external synthetic inputs by enabling to control pests, weeds, and improving fertility with ecological management. This management strategy could optimize and close resource loops (nutrients, biomass, etc.), by recycling nutrients and biomass in the farm. It may also support climate adaptation and resilience and contribute to greenhouse gas emissions mitigation, through lower use of fossil fuels and higher carbon sequestration in soils.  
As revealed by our results, the introduction of the agro-ecological management practices such as ASC, use of on-farm produced fertilizers (composts), intercropping, etc., is an interesting way to improve the sustainability of the system. In any case, the results found here could not be fully generalized, since the _Dexi-met_ model did not take into account some other aspects (e.g., the economic sustainability, the length of the study period, etc.). Moreover, when these strategies are applied, agronomic and productions difficulties should be kept in mind, at least in the short transition period between conventional and agro-ecological systems.  
The proposed modeling approach provides a simple method of decisional support to farmers to efficiently select different crop management strategies, by assessing the environmental sustainability of the cultivation systems. An interesting topic of further research could be testing the considered agro-ecological management practices in different environmental conditions.  
Conceptualization, F.M., A.P., and M.D.; formal analysis, A.P.; data curation, A.P.; writing--original draft preparation, F.M., A.P., and M.D.; writing--review and editing, F.M., A.P., and M.D.; funding acquisition, F.M. This paper is a result of the research projects RETIBIO (_Attivita di supporto tel setore dell'agricolutura biologica per il mantenimento dei dispositivi sperimentali di lungo termine e il rafuzamento delle reti di relazioni esistenti a livello nazionale e internazionale_), funded by the Organic Farming Office of the Italian Ministry of Agriculture, and SOILVEG (_Improving soil conservation and resource use in organic cropping systems for vegetable production through introduction and management of Agro-ecological Service Crops (ASC)_) funded by ERA-Net CORE Organic Plus Funding Bodies partners of the European Union's FP7 research and innovation programme under the grant agreement No. 618107.  
Conflicts of Interest: The authors declare no conflict of interest. The funders had no role in the design of the study; in the collection, analyses, or interpretation of data; in the writing of the manuscript, or in the decision to publish the results.