Studies of biological traits and karyotype of two barnyard grass variety Comparison of Ear Vascular Bundles in Different Maize Cultivars STUDY ON THE WATER CONSUMPTION LAW OF COMPLEX CROP SYSTEMS IN THE TABLELANDS OF THE EASTERN GANSU LOESS PLATEAU Characteristics of seasonal drought and its adaptation in southern China under the background of global climate change.Ⅵ. Optimized layout of cropping system for preventing and avoiding drought disaster.