Table 8. Summary of projected changes in major crop yields due to climate change, 2000–2050 Rice Region Rainfed Low Maize Irrigated High Low Sugarcane Rainfed High Low Rainfed High – Irrigated Bananas Coconuts Rainfed Rainfed SUMMARY | APRIL – – 2010 – Percent (%) 1. Luzon 1.1 Luzon 1.2 CAR 2. Visayas 3. Mindanao 3.1 Mindanao 3.2 ARMM Total –7.4 –7.5 –6.7 –4.1 –0.5 –0.4 –0.8 –4.5 –7.7 –7.8 –6.7 –3.9 –0.6 –0.5 –1.0 –4.5 –0.2 –0.2 0.2 –1.1 –0.8 –0.8 –0.9 –0.4 –0.1 –0.2 2.0 –0.6 0.7 1.0 –1.5 0.0 –18.9 –19.1 –16.6 –22.8 –18.7 –18.1 –21.3 –19.3 –20.6 –20.7 –18.6 –25.0 –21.2 –20.6 –24.1 –21.6 –8.6 –8.7 –6.6 –5.8 –0.5 –0.4 –3.9 –4.7 –3.6 –3.6 –2.2 –5.6 –1.2 –1.2 –0.4 –4.3 –11.2 –11.1 –12.3 –4.8 –1.4 –1.6 –0.1 –3.7 1.4 1.4 –1.7 0.9 2.5 2.4 2.8 1.7 Source: Calculated by authors based on DSSAT model simulation results. Notes: Grid-cell values were calculated using weights from MapSPAM 2005 (You et al. 2014). “Low” and “High” refer to levels of fertilizer (30 and 90 kilograms of nitrogen per hectare, respectively). Because the sugarcane model did not respond to changing nitrogen levels, the fertilizer variable was omitted. Table 9. Projected improvements in rainfed maize yields from various technologies, 2050 Region Droughttolerant varieties Heattolerant varieties Nitrogenefficient varieties No-till agriculture Cropdisease protection Pest protection Weed protection Integrated soil fertility management Water harvesting 34.7 32.6 42.1 32.1 31.8 31.4 34.2 32.4 0.5 0.7 0.1 0.0 0.9 1.1 0.2 0.8 Percent (%) 1. Luzon 1.1 Luzon 1.2 CAR 2. Visayas 3. Mindanao 3.1 Mindanao 3.2 ARMM Total 5.1 5.3 4.6 4.1 2.6 2.9 1.1 3.2 13.2 16.2 2.9 11.3 8.2 8.2 8.2 9.4 11.9 10.8 15.7 12.7 14.2 14.2 13.9 13.7 25.4 26.4 21.9 24.7 23.7 24.6 19.1 24.1 11.3 11.4 11.2 10.0 12.4 12.2 13.5 12.0 16.3 16.4 15.7 13.1 17.1 17.1 17.3 16.7 12.5 12.8 11.3 10.7 14.4 14.1 16.3 13.9 Source: Calculated by authors based on data from Rosegrant et al. (2014). Table 10. Projected improvements in irrigated rice from various technologies, 2050 Region Heat-tolerant varieties Nitrogenefficient varieties Precision agriculture Crop-disease protection Pest protection Weed protection Integrated soil fertility management Percent (%) 1. Luzon 1.1 Luzon 1.2 CAR 2. Visayas 3. Mindanao 3.1 Mindanao 3.2 ARMM Total 1.8 1.7 2.7 1.7 1.5 1.7 0.1 1.7 52.1 51.3 61.1 49.1 56.7 56.4 59.0 53.1 22.6 21.5 35.0 31.9 32.8 32.0 39.1 25.6 10.2 10.2 10.3 8.9 11.7 11.6 11.9 10.6 Source: Calculated by authors based on data from Rosegrant et al. (2014). 7 8.1 8.1 7.2 10.4 9.6 9.5 10.2 8.6 5.1 5.1 4.7 7.3 7.6 7.5 8.4 5.8 24.4 22.8 40.5 33.7 34.4 33.6 40.6 27.4