关键词: 滴灌, 土壤湿润区, 土壤温度, 土壤基质吸力, 根系分布, 根系耗水, 棉花

Abstract: Artemisia sphaerocephalaandA. ordosica are the two typical desert Artemisia species widely distributing in desert areas, and also, the important dominant species in sand-binding vegetation. In this study, a field survey was conducted on the wind prevention and sand resistance effects of A. sphaerocephalaandA. ordosica at the southern edge of the Tengger Desert, with the related mechanisms analyzed. Both A. sphaerocephalaand A. ordosicawere effective in reducing wind speed, and A. sphaerocephala was more effective than A. ordosica. The reduction degree of the wind speed at different positions at the back of the plants and at different heights above ground surface had distinct difference. At the positions from zero to six times plant height at the back of the plants, the wind speed reduction degree of A. sphaerocephala   at the height of 50 cm above ground surface was obviously bigger than that at the height of 20 cm, but the wind speed reduction degree of A. ordosica at the height of 20 cm above ground surface was obviously bigger than that at the height of 50 cm. At the same wind speeds, the mean wind speed at the height of 20 cm at the back of A. ordosica was half of that ofA. sphaerocephala, but the mean wind speed at the height of 50 cm of A. ordosica was near to that of A. sphaerocephala. A. sphaerocephala was weak whereasA. ordosica was stronger in sand resistance. The sand accumulation volume of A. ordosica reached 45.2±16.1 dm³, and its sand accumulation weight was 72.1±25.7 kg. There was a significant positive correlation between single plant sand accumulation volume and spatial structure of A. ordosica. A. ordosica(with compact architecture) was considered better than A. sphaerocephala (with loose architecture) in wind prevention and sand resistance. A. ordosica was characterized by more primary branches, small branching angle, and large biomass distributing at near-surface layer, which contributed to the strong effect of the plant in wind prevention and sand resistance. This conclusion provided an important basis for the species selection of sand-binding vegetation construction in arid areas.

Key words: soil wetting pattern, soil temperature, soil matrix suction, root distribution, root water consumption, cotton., drip irrigation