Contents & Foreword, Characterizing And ... - IRRI books

As Indonesia’s staple food, rice is strategically important to the agricultural developmentand economy of the country. The crop is cultivated in diverse environments.Irrigated rice occupies the largest area, followed by rainfed lowlands, uplands, andtidal swamps, with 58%, 20%, 11%, and 11%, respectively. Because of less favorableenvironments, however, the yield and production of nonirrigated rice are far lowerthan those of irrigated rice.The increasing demand for rice, along with the increasing population and lackof technological development in rice culture before the Green Revolution, has led toexpanded rice cultivation. With limited suitable land for ideal rice culture, new ricefields turned to less favorable environments.Rice fields were developed on sloping land at a higher elevation, often withoutavailable water resources except rainfall. Terraced and bunded rainfed lowland ricehelps reduce water runoff and prevents flooding in the rainy season. But the systemcannot conserve water for the dry season because most is lost through evapotranspiration.When expanded further to even higher elevation and steeper slopes, the rainfedrice system disrupts the hydrological cycle in the watershed and becomes prone todrought in the dry season.In the increasingly globalized economy with rapid progress in telecommunications,transportation, and tourism, the low productivity of rainfed lowland rice, particularlyin Java, means less competitiveness. We therefore studied the performanceof rainfed lowland rice as affected by the physical characteristics of the environmentsin Java and South Sulawesi.Rainfed lowland rice areas and their distribution in IndonesiaFigure 1 shows the distribution of rainfed rice area in Indonesia. Rainfed lowlandarea in Indonesia declined from 2.2 million ha in 1988 to 2.1 million ha in 1995 (BPS1988, 1995). There has been a slight increase in this area in Kalimantan and Sulawesi,but it is decreasing steadily in Java. The decreasing trend is also observed in Sumatraand Nusa Tenggara. The rate of conversion of rainfed lowland area to other uses ishighest in Java, with 13,800 ha annually, followed by Sumatra and Nusa Tenggara,with 6,100 and 2,700 ha per annum, respectively. The largest area of rainfed lowlandrice in the Outer Islands is in the province of South Sulawesi, with 259,100 ha or41.1% of the total rice area (Table 1). High proportions of rainfed lowland rice area inSouth Sulawesi are found in three districts in the east, Sinjai, Bone, and Wajo, with49.6%, 52.7%, and 79.6%, respectively, of the total rice area.Although not quite as high in terms of the proportion to the total rice area,rainfed lowland rice area in the three big provinces of Java is among the largest in thecountry, with a total of 786,800 ha. Central Java has the largest area, with 293,600 haor 29.4% of the total rice area, followed by East and West Java, with 252,400 and240,800 ha or 22.0% and 20.9%, respectively, of the total rice area.In Java, a large proportion of the rainfed lowland rice area is in the gently slopingnorthern coast. The districts of Lebak and Pandeglang in the northwest part ofWest Java have 43.1% and 45.9% of the total rice area. Grobogan, Blora, Pati, and146 Amien and Las