A Study On The Biological-ecological Characteristics Of Planting Three Wheat Grasses In Arid Grassland

The study was carried out on the experimental demonstration base for industrializing production technique of Agropyron during the years from 2002 to 2004 in the West Sunite Banner, Xilingol league, Inner Mongolia. Plant growth characters such as seed germination, phonological pattern, tillering, aboveground biomass and root distribution of three Wheatgrasses were explored, which enriched the basic theories and practical studies of Biological Ecology about wheatgrass and provided the evidences for production. The results were as follows: seed germination percentages were reduced when seeds were stored for longer periods and it was different for seeds produced on different parts of the spike. The three species of wheatgrasses turned to green in early season and had a long growth period. Among them Agropyron cristatum × A.desertorum cv.Hycrest Mongnon showed the longest growth period. Two obvious tillering periods were found in the three wheatgrasses. One was in the spring and another was in the autumn. The most restricting factor for tillering was soil moisture content. The amount of dry matter of Agropyron cristatum×A.desertorum cv.Hycrest Mongnon showed the curve of two peaks and those of Agropyron mongolicum and Agropyron desertorum showed the increasing tendency. The first yield peak of Agropyron cristatum was during the period of blossom and yield decreased a bit when reaching fruiting time and then increased rapidly in mature period. The yield of Agropyron cristatum×A.desertorum cv.Hycrest Mongnon was improved when diphosphate ammonia was applied before blossoming. Based on all these factors, Agropyron cristatum × A.desertorum cv.Hycrest Mongnon was a high-yield variety, but with low resistance to external stress factors. It had a high water and nutrint requirement; Agropyron mongolicum was a wild cultivated variety, which owned high endurance towards harsh environment. However, it would be degraded when it encountered the condition of several years of drought; Agropyron desertorum was the local wild species, which was better in the aspect of adaptation than the other two, and it owned the characters of high resistance and stable yield.