Agriculture in Indonesia

Abstract

The map of Indonesia suggests a high diversity in types of agriculture. The archipelago has countless different islands that stretch out over thousands of kilometers from east to west, above and below the equator. It has a rich biodiversity and the techniques the people developed to benefit from the natural environment have distinct features on each of the islands. Despite all this diversity, some clear patterns can be detected, based on three major factors. The first is the monsoon climate that divides the year into a dry and wet season with an overall high precipitation of roughly 1,700–3,000 mm in the lowlands and to over 6,000 mm in the mountainous regions. The combination of high rainfall and, for tropical conditions, not excessively high temperatures throughout the year creates a favorable climate for many different crops. The geology and elevation of the landscape is a second factor. The islands are positioned on the edges of different tectonic plates, resulting in vast mountain areas with a high number of (active) volcanoes. The eruption of volcanic ashes and the erosion of volcanic rock can create fertile ground for agriculture. In cases where volcanic sediment makes favorable soil conditions, people have used the topography to exploit this natural fertility. Such conditions are typically found on Java and Bali and some other smaller islands or parts of bigger islands. The bunded rice field (sawah) is a catchment for eroded sediments brought along by water from rivers and streams coming from the mountains. The Indonesian people constructed sawahs wherever possible but mostly in the lowlands on Java and on the hillsides, forming the now famous terraced landscapes of Bali. In most of the other main islands, these favorable conditions are found much less often. The availability of rice as a staple crop is a third determining factor. Rice was and is the main food crop in the entire archipelago. The only exceptions are the eastern areas, mainly the Moluccas and Western New Guinea, where sago, a starchy substance, was processed from the soft interior of palms, primarily the species Metroxylon sagu. It is likely that these communities survived for long periods of time solely on a combination of arboricultural techniques supplemented with hunting. This implies a reliance on the rainforest without additional agricultural techniques for (semi-) permanent crop production (Ellen, 2004). In all other places, the domestication and cultivation of rice formed the core around which many agricultural techniques developed. The climatic and geological conditions predominantly found on Java and Bali have resulted in a domestication process of rice that is specific for this region. Asian rice (Oryza sativa) has two main subspecies (or varietal groups): indica and japonica. The latter varieties typically grow in more temperate climates but are also found in tropical areas. In Indonesia a morphologically distinct group of these tropical japonicas has developed, commonly known as javanica or bulu in the local language (Vaughan, Lu, & Tomooka, 2008). The most visible characteristic of the bulus are seeds with long awns (bristle on top of seed). Characteristics that mattered most for farmers are lower sensitivity of these varieties for drought, variation in day length, intensity of sunlight, and transplanting time. These latter characteristics also make these varieties have a longer growth duration, the time between sowing and ripening. The yield potential of indica varieties is better on poorer soils, but this was not an issue for the better soils of Java, Bali, and similar places. The characteristics of the bulus allowed farmers to be more flexible in sowing, transplanting, and harvesting of rice, resulting in an overall high labor productivity. Moreover, there was a wide range of bulu varieties available to farmers. Rice, an inbreeding crop, usually produces very few natural crosses but outcrossing is relatively high in the bulu group. Farmers selected the spontaneous crosses and observed their performance in a mix and match strategy to optimize yields under different field conditions. In fields with less advantageous soil and water conditions, as mostly found on mountain slopes, indica varieties were preferred. Early colonial writers acknowledged the varietal diversity of rice on Java and other islands, but only in the early twentieth century did agronomists recognize bulus as a different subspecies and came to understand its role in farm cultivation strategies and techniques (Maat, 2001). The dominance of bulu varieties on Java and similar places gradually disappeared in the twentieth century. Improved irrigation infrastructure introduced by Dutch engineers facilitated two rice crops per year. As a result, indica varieties, having a shorter growth duration, came to dominate (Van der Eng, 1994). Colonial rice breeders tried to maintain some of the favorable characteristics of bulus through crossbreeding with indica varieties. One of the successful lines of these crosses was taken up in the 1960s by the International Rice Research Institute to develop the fertilizer-responsive variety IR8 that was massively introduced in Indonesia in the early years of the green revolution. The productivity levels realized for rice in the twentieth century using science-based technologies thus built on a much longer process of intensi-fication set in motion by the Indonesian farmers. The combination of specific rice varieties and climatic and geological conditions that dominated Java and Bali over, most likely, several millennia played a major role in the economic prosperity and contributed to a high population density in these islands. Although archaeological evidence of early times is sparse, inscriptions from about the ninth century testify the presence of large and prosperous communities across the islands (Wisseman Christie, 2004). The preference for bulu varieties makes clear that the high labor productivity in agriculture in these areas is not merely an effect of a fortuitous natural environment but involves tested strategies and techniques to optimize intensive wetland rice cultivation with various other forms of crop production in the wet monsoon season and the dry season. The control of land by local communities was left untouched by state formation that came together with the introduction of Hindu and Buddhism, followed later by Islam, creating social structures that favored the intensification of agriculture. The presence of different religions testifies frequent interactions with mainland Southeast Asia, India, and other regions. Intensive regional trade relations and global connections since early colonial settlements implied the introduction of new agricultural crops and the distribution of crops and crop varieties across the Indonesian islands. From about 1,500, rice was no longer the single source of carbohydrates (Boomgaard, 2003). Communities could thus further grow as the new crops allowed them to expand their agricultural activities on soils less suited for rice. Colonial trade relations also were an incentive to produce crops that were initially produced solely for distant markets but became fully integrated in the local economy and diet. Coffee, introduced on Java by the Dutch in the early eighteenth century, is just one example. The wealth of the Javanese and Balinese states and subsequent emphasis of colonial administra-tions resulted in a much wider availability of sources about agriculture on these islands compared to other places. This correlates with an overall bias in early colonial history that depicts the farming systems on Java and Bali as most advanced and exemplary for a development trajectory other islands inevitably had to follow. In these evolutionary projections, the sago cultures in the east are typically portrayed as most primitive. In between are agricultural practices known as shifting cultivation and semipermanent forms of agroforestry. These types of farming dominate in the mountainous and forested areas of Sumatra, Kalimantan (Indonesian Borneo), and Sulawesi. They require a variety of