Author(s)

J. Shindo, K. Okamoto, H. Toda & H. Kawashima

Abstract

Estimation of the environmental effects of excess nitrogen caused by intensive agriculture in East Asia based on global nitrogen balance J. shindo', K. Okamotol, H. ~ o d a ~ & H. ICawashima3 '~ational Institute for Agro-Environmental Sciences, Japan 2 Faculty of Science, Shinshu University, lapan 3 Graduate School of Agricultural and Life Sciences, University of Tokyo, Japan Abstract We estimated the nitrogen budget of East Asia, mainly of China, at the 0.5 by 0.5 degree scale to identify the areas and seasons which suffer from the deteriorated effects of nitrogen due to food production and supply. Data on fertilizer consumption and food balance derived from FA0 databases were used for calculating nitrogen balance in 1999 for each country. For China, province data on fertilizer consumption, rice and pulse production etc. were also used. China was divided into four zones (single-crop, double-crop (rice predominant), double-crop (wheat predominant) and double-crop-rice), and typical seasonal v

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