利用液氨直接施肥已有几十年的历史,特别是近十几年来发展速度很快。美国在50年代,液氨施用量只占全部氮肥用量的百分之十几,而到70年代已达40%,成为主要氮肥品种。我国从50年代末期也开始作了些试验,近年来,有些地区成立了专门机构,研究液氨的施用技术和增产效果,取得一些成绩。我所从1977年开始和本市有关单位协作,在北京地区试验液氨直接施用技术及其经济效益。 Direct use of liquid ammonia fertilizer has been decades of history, especially in the past decade or so the rapid development. In the 1950s, liquid ammonia application accounted for only over 10% of the total nitrogen fertilizer consumption in the United States, and reached 40% by the 1970s, becoming the major nitrogenous fertilizer variety. Since the late 1950s, China has also started some experiments. In recent years, specialized agencies have been set up in some areas to study the application technology of liquid ammonia and increase the yield and achieve some results. Since 1977, we have been cooperating with relevant agencies in our city to test the direct liquid ammonia application technology and its economic benefits in Beijing.