Grain production and environmental management in China's fertilizer economy

The rapid growth in China's per hectare chemical fertilizer application, from less than 10 kg in 1960 to 331 kg in 1993, has contributed significantly to the growth in grain production, but has also caused many environment problems such as groundwater pollution. With one-fifth of the world's population but only 7% of the earth's arable land, China is facing the challenge of increasing grain production and protecting the environment. This paper analyzes the contribution of both chemical and organic fertilizer to China's grain yield improvement since 1952 and discusses policy implications for improving fertilizer efficiency and reducing groundwater pollution. A quantitative estimation of the major sources of China's fertilizer supply shows that organic fertilizer was dominated by chemical fertilizer in terms of total plant nutrient supply by 1982 but that it still plays an important role in Chinese agriculture. A grain yield response function is then constructed to estimate the contribution of fertilizer and other factors to China's grain yield growth. Results indicate that the changes in grain yields during 1952-1993 were significantly determined by fertilizer application as well as by technological and institutional changes. China's fertilizer-related environmental problems require urgent attention because of their impacts on the global environment as well as on the welfare of a large proportion of the world's population. Major suggestions for improving China's fertilizer efficiency are to increase the proportion of phosphates and potash application and to adjust the highly skewed chemical fertilizer distribution by allocating more fertilizer to areas with low and medium application rates. (C) 1996 Academic Press Limited.