关中地处秦岭与北山之间,西起宝鸡,东至潼关。除秦岭、乔山、黄龙山外,包括陕西省中部的咸阳、渭南两个地区,西安、宝鸡,铜川三个市。地下肥水(以下简称肥水)是关中农民在长期生产斗争实践中发现和利用的一种含有相当数量硝态氮的浅层地下水, Guanzhong is located between Qinling Mountains and Beishan, west from Baoji, east of Tongguan. In addition to Qinling, Qiaoshan, Huanglongshan, including the central Shaanxi Province in Xianyang, Weinan two areas, Xi’an, Baoji, Tongchuan three cities. Underground fertilizer (hereinafter referred to as fertilizer) is a kind of shallow groundwater containing a considerable amount of nitrate nitrogen found and utilized by peasants in Guanzhong during long-term production struggle.