GRAIN PRODUCTION AND ENVIRONMENTAL-MANAGEMENT IN CHINA FERTILIZER ECONOMY

The rapid growth in China's per hectare chemical fertilizer applicatio n, from less than 10 kg in 1960 to 331 kg in 1993, has contributed sig nificantly 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 m ajor sources of China's fertilizer supply shows that organic fertilize r was dominated by chemical fertilizer in terms of total plant nutrien t supply by 1982 but that it still plays an important role in Chinese agriculture. A grain yield response function is then constructed to es timate the contribution of fertilizer and other factors to China's gra in yield growth. Results indicate that the changes in grain yields dur ing 1952-1993 were significantly determined by fertilizer application as well as by technological and institutional changes. China's fertili zer-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 im proving China's fertilizer efficiency are to increase the proportion o f phosphates and potash application and to adjust the highly skewed ch emical fertilizer distribution by allocating more fertilizer to areas with low and medium application rates. (C) 1996 Academic Press Limited .