## 3 Results and Discussion  
The suitable areas found for the four cereal/legume classes are indicated in Table 2 and mapped in Figure 4. It can be noticed that a prevalence was established for oat/lupin and triticale/broad bean pairs with 16,045 ha and 17,383 ha, respectively. As mentioned above, the assignment of soil conditions assumed overlapping areas to lupin and broad bean and oat and triticale, respectively, due to similarities in soil requirements for the legume crops with these cereals. The total modeled potential cereal area for Alentejo was 44,980 ha, which can be compared to totals of actual occupied areas of about 89,472 ha for the whole country in the period between 2019 and 2023 if considered that about 80% of these cultivations were located in the region. The modeled areas, corresponding to good soil productive conditions in Alentejo, compared to total soil occupation areas in the country for oat, triticale, barley, and wheat in 2015 of 49,400 ha, 21,600 ha, 20,100 ha, and 35,800 ha, respectively. These area results, coupled with available information on productivity, calorific power, and straw yield, allow for the establishment of mass and energy balances [7, 46, 47]. The results of field validation in the 199 sampled points are posted in Table 3. For practical effects, related to the yearly variability of real annual cultivations, the observed cultivations in the field were grouped into eight classes, which, besides individual oat (8 points), barley (5 points), wheat (7 points), and triticale (2 points), included forage intercropping (50 points), breeding pasture (3 points), tilled soils (6 points), and natural pastures (118 points). Table 3 shows that, despite few direct correspondences, a potential match between the chosen and observed cereal classes was verified, due to the preponderance of forage intercropping or natural pasture soil use classes. The former was an aggregated class, including patch points with at least one of the four initial cereal classes, and the latter was a class where neither any sown was applied nor possible plant sowings did thrive due to lower rainfall in Alentejo in the years 2022 and 2023. Indeed, the annual accumulated rainfall in Alentejo in these years corresponded to 75% and 50% of the average of the period between 1981 and 2010. \begin{table}
\begin{tabular}{c c c c c} \hline  & **Oat/Lupin** & **Triticale/Broad Bean** & **Barley** & **Wheat** \\ \hline Slope \textless{} 5\%, & & & & \\ Elevation \textless{} 300 m & 16,045 & 17,383 & 1587 & 9965 \\ \hline \end{tabular}
\end{table} 
Table 2: Areas (in hectares) of the cereal and legume crops for slopes lower than 5% and elevations lower than 300 m.  
Figure 3: Mass and energy balances for thermochemical conversion. Figure 4: Suitability map for the selected cereal and legume crops in Alentejo areas with slopes lower than 5% and elevations lower than 300 m. \begin{table}
\begin{tabular}{c c c} \hline \hline
**Observed Cultivation** & \
\begin{tabular}{c} **Number of Field Points Matching** \\ **One of the Four Soil-Use Groups** \\ \end{tabular} &
\begin{tabular}{c} **Matched Initial** \\ **Classes** \\ \end{tabular} \\ \hline \multirow{2}{*}{Barley} & 2 & Wheat \\  & 3 & Triticale \\ \hline \multirow{2}{*}{Oat} & 1 & Oat/lupin \\  & 4 & Barley \\  & 3 & Triticale \\ \hline \multirow{2}{*}{Wheat} & 2 & Oat/lupin \\  & 5 & Wheat \\ \hline \multirow{2}{*}{Triticale} & 1 & Oat/lupin \\  & 1 & Barley \\ \hline \multirow{2}{*}{Forage intercropping} & 10 & Oat/lupin \\  & 11 & Barley \\ \cline{1-1}  & 13 & Wheat \\ \cline{1-1}  & 16 & Triticale \\ \hline \end{tabular}
\end{table} 
Table 3: Correspondences between initial and observed cereal classes in field points sampled in 2023. In Portugal, the spring of 2023 was the third driest since 1931, and the accumulated rainfall of 100 mm corresponded to about 50% of the normal value. This fact is related to the actual climate change context, with a real impact in the Mediterranean basin [48; 49].