【摘要】 <正> 施肥是作物增产的重要手段。尤其是化肥施用,已成为现代农业生产中一项重要的技术措施。据联合国粮农组织以及各国专家的估计,粮食增产量中,30％～60％应归功于化肥的施用。中国农科院土壤肥料研究所张夫道等统计分析了我国解放后三十年农作物产量后指出,我国粮棉总产水平与化肥氮磷钾施用水平呈极显著的正相关。但另一方面,随着化肥等商品能投入的增加,使农业对外界的依赖性越来越大。1987年我国化肥施用量已达8377万吨,比1980年增加57.5％。化肥投入要占农作物生产物更多还原

【Abstract】 The authors Consider that rational fertilization is a system engineering. Its main tasks are chemical fertilizer allocation, recommended fertilization,and the regionalization, forecast and plan of fertilizers for improving social, ecological and economic benefits of fertilizer use. The structure, basic steps and some quantitative relations in the system engineering are put forward and analysed.更多还原