Crop Yield Response to Water and Fertilizer in Loess Tableland of China：A Field Research

This paper describes a field research on crop yield response to water and fertilizer in Changwu tableland of the Loess plaeau.Under the current level of land management in this area.low fertility of soil is the first yield-limiting factor and water deficit is the second.At a given fertility level,the relationship between crop yield and its water consumption is parabolic.Within a certain rage of soil moisture,the soil water availability to crop is not sharply deceased with its markedly decreasing content,Because of this relatively high availability and the gigh reserve of soil water at the early stage of crop growth,drought due to inadequate or poorly distributed rainfall becomes less serious.High fertilizer input ,improved crop variety and optimum cultivation technique can give a 50-100% yield increment of dryland crops in the loess tableland.