Analisis Salinitas dan Dampaknya terhadap Produktivitas Padi di Wilayah Pesisir Indramayu

Abstract

Indramayu District is one of main rice production centre in West Java. Most of rice fields locate next to Java’s North Coast and some of the areas are influenced by salinity problem. The problem of salinity increases during dry season particularly when irrigation water is limited as salt water intrusion will increases under this condition. The salinity problem will be more severe when dry season extends. Under high salinity condition, yield of rice will decrease significantly. This study analyzed the spatial distribution of salinity and its changes in the rice field during dry season and its impact on rice yield. The salinity were measured during dry season (July, October and November) in a number of location and yield of rice was measured in the same location from a plot with size of area of size 2.5x2.5 m2 in November. It was found that the salinity decreased with distance from the coast. In some area near the cost, the salinity could go up to 9 dS/m and most this area had been converted to pond or salt mining or other uses. In most of paddy fields affected by salinity have salinity level of less than 5.5 dS/m. The area of paddy field affected by salinity expanded as the rainfall in the dry season decreased. The rice yield was not significantly affected by the salinity. This study suggests that the current rice variety used by farmers is tolerant to salinity. However, the risk of salinity may increase in the future due to change in sea level and coastal characteristics (e.g. degradation and conversion of mangrove forests). Current rice variety may be tolerant to salinity of not more than 5.5 dS/m. Adapting to increasing risk of salinity, it is very important to introduce alternative rice varieties which are more tolerant to salinity, restoration of mangrove forest and also improvement of irrigation facilities.