Soil moisture and nutrient distribution, and their effect on cropland productivity in the tableland area of the Loess Plateau, were studied. For major crops, the following characteristics were investigated: sensitivity to water stress at different stages of growth, methods for improvement of crop water use efficiency and soil nutrient input and output of a cropland ecosystem in the tableland area of the Loess Plateau. This chapter discusses how soil fertility can be improved in a cropland ecosystem, the effects of fertiliser on crop productivity under different patterns of rainfall, how fertiliser use can be linked to productivity, optimum fertilisation and factors affecting the efficiency of fertiliser use. It describes key factors limiting cropland productivity and the main measures by which productivity can be increased in the tablelands of the Loess Plateau.