## 4 Electromagnetic Climate Map for Suitable Cultivation Areas for Forage Crops  
The production prediction model developed in Section 3, based on the climate impacts of grasses and IRG, could explain the vulnerability of forage crops to climate effects. In addition, it could facilitate the prediction of changes in the cultivation areas of grasses and IRG in response to various climate change scenarios. However, the electromagnetic climate map in this study only dealt with the electromagnetic climate map of the movement of the suitable cultivation area, which was built by limiting items and criteria, such as the soil and variety, for the climate effect. The reference value for the cultivation area of IRG, a winter forage crop, was established based on the average minimum temperature in January. The best suitable areas were defined as areas with temperatures of \(-5\)\({}^{\circ}\)C or above. The suitable areas were defined as areas with temperatures of \(-9\)\({}^{\circ}\)C or above and potential areas were defined as areas with temperatures of \(-12\)\({}^{\circ}\)C or above. The five-year average minimum temperature in January, spanning from 2017 to 2021, established the baseline. Additionally, the analysis value represented the average minimum temperature in January as of 2022. Figure 7 shows an electromagnetic climate map for the IRG cultivation area. The ratio of suitable cultivation area for IRG is shown in Table 9. For the analysis value, an increase was observed in areas with low production, while a decrease occurred in the optimal area due to temperatures lower than usual. In general, the proportion of the area corresponding to the analysis value for suitable or better conditions decreased compared to the reference value, whereas the proportion for the possible or low-production area increased. The criterion for the suitable grass cultivation area was defined based on the average maximum temperature in August. The optimal area was set for areas with temperatures \begin{table}
\begin{tabular}{c c c c c} \hline \hline
**Category** & **Best Suitable** & **Suitable** & **Possible** & **Low Production** \\ (**AVGMINTJAN**) & (C\(-5\)\({}^{\circ}\)C) & (\(-5\)\({}^{\circ}\)C\(-9\)\({}^{\circ}\)C) & (\(-9\)\({}^{\circ}\)C\(-12\)\({}^{\circ}\)C) & (\(<\)\(-12\)\({}^{\circ}\)C) \\ \hline Result of Year (2022) & 27\% & 39\% & 22\% & 12\% \\ \hline Result of Past 5 Years (2017-2021) & 32\% & 51\% & 15\% & 2\% \\ \hline \hline \end{tabular}
\end{table} 
Table 9: Ratio of suitable cultivation areas for IRG. Figure 7: Electromagnetic climate map of suitable cultivation areas for IRG. below 25 \({}^{\circ}\)C. The suitable area was set for areas with temperatures of 26 to 28 \({}^{\circ}\)C. The possible area was set for areas with temperatures of 29 to 31 \({}^{\circ}\)C and the low production area was set for areas with temperatures over 32 \({}^{\circ}\)C. The reference value used to create the electromagnetic climate map was established as the five-year average maximum temperature in August from 2017 to 2021. Table 10 shows the ratio of suitable cultivation areas for forage grass. The analysis value, on the other hand, was determined as the average maximum temperature in August for the year 2022. As shown in Figure 8, the analysis of suitable grass cultivation areas revealed an increase in the proportion of suitable or optimal areas compared to the reference value. This increase was attributed to lower summer temperatures compared to typical years. It is anticipated that accurate predictions of changes in cultivation area movement can be achieved by gathering additional data and developing an electromagnetic climate map in the coming years. Figure 9 shows the electromagnetic map used for predicting forage crop productivity. The map reveals that the maximum yield, reaching 16,151 kg/ha, is predominantly concentrated in the Jeju region and certain coastal areas. Conversely, the minimum yield, at 426.9 kg/ha, is primarily observed in the alpine regions in Gangwon-do as well as mid-northern and high-altitude areas.