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在国外,尿素等氮素化肥是水稻的主要肥料,许多国家每年的用量都很大。1978年仅东南亚就用了30万吨,1983年预计达300万吨。
In other countries, nitrogenous fertilizers such as urea are the main fertilizers of rice and are used in large quantities in many countries every year. In 1978, only 300,000 tons were used in Southeast Asia and 3 million tons in 1983.