摘要
研究了不同水分处理下 ,乌兰布和沙区紫花苜蓿根系生长发育规律及根系吸水速率。结果表明 :不同水分处理的根系生长规律是基本一致的 ,在生长季内均呈增加的趋势 ;但适度干旱可促进根系的伸长生长。在当地土壤类型条件下 ,根系主要分布在 0～ 30 cm土层 ;根重密度在土壤剖面上的分布遵循对数规律 ,并随深度的增加呈降低趋势。运用一维土壤水分运动方程 ,计算得到了不同水分处理根系吸水速率在土壤剖面上的分布状况 ;
A field study was conducted in Wulanbuhe sandy region to determine the effect of water supply on roots growth and water uptake of alfalfa ( Medicago sativa L.). 3 treatments with different irrigation methods and watering frequency were arranged. One treatment received 133 mm in 3 flooding applications (W1 and W3), the second received 103 mm from a sprinkler application (W1 and W2). The final treatment was 33 mm from a sprinkler (W3). An increasing tendency of roots growth was observed in all the 3 treatments. However there was a between treatment difference in rooting depth: moderate drought stimulated root elongation. Local roots of alfalfa mainly developed in the top 30 cm of soil and their number decreased greatly with depth. In this paper a logarithmic function was introduced to describe the root weight density distribution in the soil profile and 3 regression equations representing root density were established for the 3 treatments respectively. Finally, root water uptake rates at different growth stages of alfalfa in each treatment were simulated by applying of the theory of soil water dynamics.
出处
《植物生态学报》
CAS
CSCD
北大核心
2001年第1期35-41,共7页
Chinese Journal of Plant Ecology
基金
国家重点基础研究发展规划项目 !(19990 1170 9)
国家自然科学重大基金! (89990 490 )
