ABSTRACT

Since the early 1960s, food production in Asia increased at rates and to levels that are unprecedented. Total cereal production, for example, increased from 329 to 1059 million tons (MT) between 1961 and 2005 (FAO, 2006). Much of this gain was due to new varieties with high harvest indexes, intensive use of farm chemicals, expanded irrigation, and advances in farm management. Between 1961 and 2002, fertilizer use in Asia increased from 3.8 to 77 MT, irrigated area from 90 to 194 million ha, and the total number of tractors in use (an indicator of farm mechanization) increased from 200,000 to 7.5 million (FAO, 2006). Recent reports, however, indicate many threats to long-term sustainability of cropping systems. For instance, the rice-wheat rotation, which is the basis of food security in much of South Asia, presents such problems as loss of organic matter, nutrient mining, salinity, waterlogging, and buildup of weeds, pests, etc. Ali and Byerlee (2000) reported a decline of total factor productivity of 0.44 percent per annum in the wheat-rice system in Pakistan from 1971 to 1994. High rates of nutrient and pesticide leaching, pesticide resistance in insects and pathogens, and biodiversity loss have become all too familiar in Asian farming. Nitrate pollution of drinking water in tobacco and rice ecosystems of Malaysia (Ahmad et al., 1996) and of groundwater in Japan (Nishio, 1999), India (Sinha, 1997), and China (Zhang, 2001), and increased soil erosion in Nepal (Carson, 1992) are a few examples. Asia is also characterized by dwindling per capita arable land and water reserves, escalating production costs, and growing food demands due to an increasing and urbanizing population with rising incomes and associated changes in lifestyle and food preferences.