Abstract: Based on three years field experiments at Dingxi county of Gansu province, this paper compares and analyses the primary productivity, climatic resource utilization efficiency, characteristics of energy and matter cyclings and water adaptability of various crops such as spring wheat, pea, hyacinth bean, naked-oat, crown-flax, millit, potato, lucerne, sweatclover and sainfoin etc. It is considered that the development of grassland agriculture and the establishment of a new cropping system combining cereal crops and fodder grasses in proper proportion are scientific for the semi-arid Loess hilly region. Increasing field input and soil fertilization are critical to enhancing farmland productivity.

Key words: land use type, soil quality index, natural forest, rubber plantation, tea garden, paddy field