The suitability classification of SPT group for each investigated crops are shown in Figure 4.3.
Figure 4.3. Suitability map of Land Map Unit for each crop
4.3. Slope Map
Most of Bantul Regency are flat plain areas with slope of less than 2 , and the distribution of plain area are in the northern, middle and southern parts of
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Bantul Regency covering an area of about 31,421 Ha 61.99 . Most of the eastern and western areas have slope from 2.1 up to 40 and cover about 15,148
Ha 30 , and the rest of the area have slope of more than 40 . Based on the criteria of land suitability that published by Puslittanak, some
investigated crop have the same the classification as slope suitability. The crops, which have same classification were corn, mungbean, peanut, and soybean. Rice
need more flat area for its growth, so the areas, which have slope more than 8 is classified as not suitable area.
Figure 4.4. Slope class suitability map for Corn
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Figure 4.5. Slope class suitability map for Rice
Figure 4.6. Slope class suitability map for Mungbean
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Figure 4.7. Slope class suitability map for Soybean
Figure 4.8. Slope class suitability map for Peanut 34
4.4. Temperature Map
Temperature zone in research area is made by using Braak formula with contour data as an input. The classification of temperature is based on the
temperature suitability classification for each crop which issued by Puslittanak. Generally, the temperature of Bantul Regency is suitable for all crops
investigated. According to Puslittanak land suitability classification, the suitable temperature needed for almost all investigated crop are between 16° C up to
34° C, except Mungbean needed the temperature cooler than others that is between 8° C up to 30° C for its optimum growth. The temperature suitability
map for all investigated crops can be seen in Figure 4.9 to 4.13.
Figure 4.9. Temperature suitability map for Peanut
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Figure 4.10. Temperature suitability map for Corn
Figure 4.11. Temperature suitability map for Mungbean
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37 Figure 4.12. Temperature suitability map for Rice
Figure 4.13. Temperature suitability map for Soybean
4.5. Rainfall Map
The water availability zones were obtained from the isohyet line of rainfall average data of several rainfall observation stations rainfall data can be seen in
Appendix 6. Based on average hydrological data series, it shows that the water availability were not become a limitation factor for growing the investigated
crops. There were no unsuitability areas of water availability level in the research area, the water availability level for all investigated crops at least on marginally
suitability level. According to Puslittanak Land Suitability Criteria and discussion result with
expert from Puslittanak, water availability level for rice was not based on rainfall but more from the wet area rice field irrigation areas. The areas outside the wet
area were classified as marginally suitable areas. Areas that are suitable for mungbean were found in the area where water availability has marginally suitable
level. Suitability map of water availability for all crops can be seen in Figures 4.14 to 4.18.
Figure 4.14. Water available suitability map for Mungbean
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Figure 4.15. Water available suitability map for Rice
Figure 4.16. Water available suitability map for Corn
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40 Figure 4.17. Water available suitability map for Peanut
Figure 4.18. Water available suitability map for Soybean
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4.6. Overlay Process and Weighting Analysis
