The methods of digging and lcaching millet roots in the fields were used to study the laws of growth and development of millet root system. Also,P fertilizerapplication trials,plastic sheet in cultivation and sowing at different stages in millet cul-tivation were cmployed to exam the environmental effects upon millet root systemgrowth and development.The results indicated:a matured millet plant held 40~80 rhi-zocarpic roots in 6~8 rounds with a depth of 150cm in soil and the extended diameter of 90cm,most o...