盐分胁迫条件下苜蓿根系吸水特性的模拟与分析

体文借鉴Ｈｏｍａｅｅ有关盐分胁迫的部分试验研究结果及一种新的数值迭代反求方法，对无水分、养分限制条件下，Ｈｏｍａｅｅ苜蓿盐分胁迫试验中苜蓿根系的吸水规律进行了数值模拟与分析，提出了一种计算相对根长密度分布函数的简便计算方法，建立了盐分胁迫条件下苜蓿根系的吸水模型．结果表明：盐分的存在会显著降低苜蓿的根系吸水速率，当土壤溶液的电导率达到约５ｄＳ／ｍ时，将极大地影响苜蓿的根系吸水；本文提出的计算相对根长密度分布函数的计算方法较为简便、可靠；基于相对根长密度分布函数的吸水模型可以较好地模拟根系的吸水规律．

Simulation to Water Uptake Rate by the Roots of Alfalfa under Salinity Stress

In this paper, the root water uptake rate of alfalfa under salinity stress (without water or nu- trient stress) were simulated and analyzed, and an easier method for calculation of the distribution function of relative root length density was put forward. The experimental data were chosen from Homaee' s alfalfa growth experiment under salinity stress. The results showed that: (1) salt in the soil reduced the root water uptake rate of alfalfa remarkably when the electric conductivity of soil solution was higher than 5 dS/m; (2) the method for calculation of the distribution function of relative root length density could be used reliably to simulate root water uptake characteristics of plants.