Changes in Food Production and Environmental Effects Associated with Economic Growth: A Comparative Study of China and India

中国とインドの食料生産・消費に伴う窒素フローを統計データに基づいて推定し、1961 年から2005 年の45 年間の食料消費傾向の変化を比較した。中国では改革開放政策が開始された1980年頃から一人当たりタンパク質消費量が急増し、特に肉・卵など畜産品の消費拡大が顕著である。インドでも同時期に一人当たり消費量の増加が見られるが増加率は小さく1990 年の新経済政策以降はむしろ減少傾向にある。この間人口は中国で2 倍、インドで2.5 倍に増加し、増大する作物需要を満たすために、両国とも化学肥料使用量が急増し、農地における過剰窒素が環境への負荷となっていると推定された。日本や東南アジアを含むインド以東のアジアを対象に、農地からの窒素流出、人の食生活からの排出、大気沈着を考慮して河川水窒素濃度分布を推定した結果、中国華北平原東部や東北地方で広域的に汚染が進んでいること、インドではガンジス平原部および南部の河川で高濃度であることが推定された。Nitrogen flow associated with food production and consumption was estimated for China and India and dietary changes during 45 years from 1961 to 2005 were compared. Per capita protein intake has rapidly increased, especially due to the increase of meat and egg consumption in China since the economic reforms around 1980. In India, per capita intake increased slowly in the 1980s while it tended to decrease after the 1990s. Population increased by 2 times in China and 2.5 times in India in this period of 45 years and there has been a greater demand for food. In order to produce enough food, increasing amounts of chemical fertilizer are being used recently and the nitrogen surplus in farmland is considered to cause an environmental burden. The spatial distribution of nitrogen concentration in river water was estimated by taking the nitrogen leaching from farmland, human waste and atmospheric deposition into consideration for India and eastward Asian countries. It was predicted that wide areas close to the east coast of Northern and Central China were highly polluted with nitrogen and that rivers in the Gangetic Plain and southern part of India had high concentrations