Climate variability and dynamics of rice planting time in the monsoonal and equatorial region

Abstract

Apriyana Y, Kailaku TE. 2015. Climate variability and dynamics of rice planting time in the monsoonal and equatorial region. Pros Sem Nas Masy Biodiv Indon 1 (2): 366-372. Climate variability in Indonesia, characterized by increased fluctuations, frequency and intensity of climate anomalies in the last decade due to the phenomenon of ENSO (El Niño Southern Oscillation) and IOD (Indian Ocean Dipole) cause changes in distribution patterns and intensity of rainfall, as such the beginning of the drought season and the rainy season becomes late. These conditions eventually affect the time and pattern of food crops in regions with equatorial and monsoonal rainfall pattern. The objective of this study to determine the impact of climate variability on rice planting time in regions with different rainfall patterns. Desk work in rice production centers was conducted at regions with monsoonal and equatorial rainfall patterns, i.e. district Karawang and Pesisir Selatan respectively. The study was started by (i) collecting rainfall data and information map from rainfall and climatology station; (ii) examining regional climate through analysis of rainfall distribution in the study area followed by the determination of the impact of climate variability, then analysis of rainfall relationship with indicators of climate anomalies; and (iii) analysis of the dynamics of planting time. The results showed that the impact of regional climate variability on the decrease of rainfall started in the period September-November both in Karawang and in Pesisir Selatan. The influence of climate anomalies in the region with monsoonal rainfall pattern is higher than one in the region with the equatorial rainfall. The planting time delayed 2-6 decadal (ten days period) in Karawang due to ENSO and IOD phenomenon, whereas in Pesisir Selatan the planting is not shifted compared to normal conditions. In Karawang, all areas affected by climate anomalies showed a decrease in harvested area on JulyOctober, while peak planting occurred in December. In Pesisir Selatan, increasing climate anomalies both ENSO and IOD was followed by a decrease in planting area in September and October. In areas not affected by regional climate, planting peak occurred in October while in affected areas, the peak occurred in December.