## 4 Conclusions  
In this study, a modeling of the bioenergy production potential from six cereal and legume cultivations was carried out in the Alentejo region in Southern Portugal, with a GIS-based estimation of potential areas based on the physical and chemical soil requirements of these crops. The cereals were wheat, barley, oat, and tritticale, and the legumes were lupin and broad bean. Lupin and broad bean were considered as interchangeable with oat and tritticale, due to the similarity of their soil requirements, thereby allowing for a set of four crops. The area estimation used soil and topography digital datasets which were overlaid, delivering uneven areas of the cultivation classes covering approximately the municipalities of Beja, Serpa, Mourao, and Mertola. The estimated areas were subjected to field validation in 199 points. Mass and energy balances for straw biomasses were established, assuming yields of 6, 9, 6, and 9 tonsha\({}^{-1}\) were considered for the four classes in the indicated order, along with biomass net calorific values of 18 MJkg\({}^{-1}\). The total modeled potential area for Alentejo for the four cultivation classes was 44,980 ha. Two alternatives of use of biomass for the bioenergy exclusively and of 50% for animal feed were considered. The total bioenergy estimated without animal feed was 5882 Tly\({}^{-1}\), an amount corresponding to about 25% of the total energy produced in Alentejo in 2022. Considering the application of 50% of straw biomass for animal feed, the bioenergy produced would be half of the total value. For local exclusive bioenergy production, the alternatives proposed were 71 units of heat and power co-generation under ORC 2.5 MW and 694 units of 125 kW boilers for heat production. The corresponding annual avoided fossil CO\({}_{2}\) emissions would be higher than 320 kton, delivering thereby a circular contribution to an atmospheric neutral carbon budget. Besides the contribution to the reduction in the large cereal dependence of carbon emissions of the country, the proposed strategy would contribute to increasing the decentralized bioenergy production for application in local facilities and buildings, significantly boosting the socio-economic dynamics of these rural communities.  
Conceptualization, A.R., A.B.G. and P.B.; methodology, A.R. and A.B.G.; software, A.B.G.; validation, A.R., A.B.G., B.M., A.C. and P.B.; formal analysis, A.R. and A.B.G.; investigation, A.R. and A.B.G.; resources, A.R., A.B.G. and P.B.; data curation, A.R. and A.B.G.; writing--original draft preparation, A.R. and A.B.G.; writing--review and editing, A.R., A.B.G., B.M., A.C. and P.B.; visualization, A.B.G.; supervision, A.R., A.B.G. and P.B.; project administration, A.R.; funding acquisition, A.R., B.M., A.C. and P.B. All authors have read and agreed to the published version of the manuscript.  
This research was funded by the Portugal 2020 R&D project \"SynDiesel: Diesel engine fuel from thermal gasification of agricultural wastes and dedicate crops\", Ref. ALT20-03-0145-FEDER-039485. This work was supported by FCT--Fundacao para a Ciencia e a Tecnologia, I.P. for its financial support via the projects LAETA Programmatic Funding (DOI: 10.54499/UIDP/50022/2020), GeoBioTec Research Center (DOI: 10.54499/UIDB/04035/2020), and CERIS Research Center (DOI: 10.54499/UIDB/04625/2020).  
Not applicable.  
The data that support the findings of this study are available from the corresponding author upon reasonable request. The data are not publicly available due to privacy.  
The authors declare no conflicts of interest.