通过在扬中县境内南北两地的田间试验,表明在该地配合施用氮、磷、钾化肥,不论用量如何,或是分期施用和在有机肥基础上施用,对当季水稻都没有增产效果,因此提出了一个所谓化肥——粮食微观经济转换零效率的概念。产生这种现象的原因,主要是因为该地人口压力大,土地利用强度高,长期来进行强化的粮食生产,大量施用化肥的结果。作者分析了在零效率条件下化肥能耗和土壤物质循环规律的特点,指出一个地区的化肥效率可能和人口密度有关系,把零效率视为高密度人口组成农田生态系统中的一种反馈机制。在没有技术突破的情况下,农田生态系统的演替正在向顶极发展。如何避免这种现象,是土壤生态学的重要课题。 Through the field experiment in North and South of Yangzhong County, it is indicated that the application of nitrogen, phosphorus and potassium fertilizers in this area, no matter the amount of application, or the application in phases and on the basis of organic fertilizer, Therefore, a so-called concept of zero-efficiency of fertilizer-food micro-economic transformation was put forward. The reason for this phenomenon is mainly due to the population pressure in the area, the high intensity of land use, the intensified food production in the long term and the result of large-scale application of chemical fertilizers. The author analyzes the characteristics of fertilizer energy consumption and soil material cycling under zero-efficiency conditions and points out that the efficiency of fertilizer in a region may be related to population density. Zero-efficiency is considered as a feedback mechanism in high-density population composition farmland ecosystem . In the absence of technological breakthroughs, the succession of farmland ecosystems is on the upswing. How to avoid this phenomenon is an important issue in soil ecology.