中文摘要：

近年来，水资源短缺问题日益突出，节水农业成为研究热点，其中最主要的课题当属探索作物根系吸水规律并准确地模拟土壤作物系统中的水分运移．通过设置冬小麦（苗期）室内水培实验，本文探索了冬小麦根系吸水功能与根氮质量之间的关系，并据此建立了根系吸水模型，之后，通过冬小麦（苗期）室内砂培土柱实验，对该关系和基于根氮质量密度的根系吸水模型进行了检验验证，模拟分析了土柱实验各处理条件下土壤-冬小麦系统中的水分运移规律．结果表明：冬小麦根系吸水（蒸腾）与根氮质量呈较好的线性相关（R2=0．99），基于根氮质量密度可建立根系吸水模型，并模拟冬小麦各生长阶段土柱中的土壤水分动态，剖面含水量的模拟值与实测值吻合较好，两者间的均方根差均在0．007cm3cm-3之内．

英文摘要：

In recent years, the water resources shortage is becoming a serious worldwide problem for the agriculture production. Numerous works focused on understanding the root-water-uptake rule and simulating soil water dynamics accurately in a soil-crop system. In order to investigate the relationship between root-water-uptake function and root nitrogen mass of winter wheat, an experiment with winter wheat seedlings cultured in nutrient solution was conducted in this study. Thereupon, a root-water-uptake model based on root nitrogen mass density distribution was proposed. Another experiment with winter wheat seedlings cultured in sandy soil columns was designed to examine the established root-water-uptake model and to simulate soil water flow in the soil-wheat system under various controlled conditions. Results showed that the root-water-uptake （transpiration） was linearly to the root nitrogen mass of winter wheat （Re 0.99）. The root-water-uptake model based on the root ss density distribution was effective and reliable in simulating soil water dynamics in the soil column and the simulated soil water content distributions during different growth periods of winter wheat with the measured values, with the root mean squared errors between them less than 0. 007 cm3 cm-3.