土壤水分及氮素淋失胁迫下根系吸水过程的模拟

发布时间：2018-01-31 18:44

本文关键词： 水分亏缺氮素淋失根系吸水动态响应 Penman-Monterith模型　出处：《西北农林科技大学学报(自然科学版)》2017年12期 　论文类型：期刊论文

【摘要】：【目的】提出西藏高原农业种植区土壤水分亏缺、氮素淋失等因素耦合作用下的作物根系吸水胁迫响应函数,并基于Penman-Monteith公式构建作物根系吸水模型。【方法】于2015年春青稞生育期,在江达灌区和西藏农牧学院农田水利实验场开展同步试验,测定灌区典型田块及实验室参照模式和常规模式下的春青稞根系吸水过程、土壤水分及NH+4-N和NO-3-N淋失过程,基于全局性最优方法率定了根系吸水模型参数,采用Nash-Sutcliffe系数和相对均方根误差对模拟精度进行检验。【结果】所构建的根系吸水模型可用于边界条件控制及土壤水分亏缺和氮素流失耦合作用下根系吸水胁迫响应关系的模拟,在春青稞全生育期内,模拟结果的Nash-Sutcliffe系数和相对均方根误差分别为0.74和0.050 8,生育阶段中Nash-Sutcliffe系数和相对均方根误差的最大模拟偏差分别为0.63和0.102。【结论】所提出的模型能够有效描述西藏高原农业种植区土壤水分亏缺和氮素淋失条件下的根系吸水过程,具有较高的模拟精度。
[Abstract]:[Objective] proposed agriculture planting area soil water deficit in Tibet plateau, the response function of water coupling effect of crop root nitrogen leaching and other factors under the stress, and the Penman-Monteith formula to construct crop root uptake model based on. [method] in 2015 spring barley growth period, in the river of irrigation district and Tibet Institute of agriculture and animal husbandry of farmland water conservancy experiment field to carry out synchronous test spring barley, root water uptake determination of typical field irrigation and laboratory reference mode and conventional mode, soil moisture and NH+4-N and NO-3-N leaching process, the global optimal method of calibration parameters of root water uptake model based on the test of simulation precision by using Nash-Sutcliffe coefficient and relative root mean square error. [results] the root water uptake model the construction can be used to control response between the boundary conditions and soil water deficit and nitrogen loss under the coupling of root water stress The simulation in spring barley during the whole growth period, Nash-Sutcliffe coefficient of simulation results and the relative root mean square error is 0.74 and 0.0508 respectively, the maximum deviation of simulated Nash-Sutcliffe coefficient in the whole growth period and the relative root mean square error was 0.63 and 0.102. respectively. [Conclusion] the proposed model can effectively describe the agricultural planting and water absorption of the root zone soil moisture the deficit and nitrogen leaching conditions of Tibet plateau, with high accuracy.

【作者单位】：西藏农牧学院;
【基金】：西藏自治区科技厅农牧业科技成果转化与示范项目“西藏农业面源污染调查与防控技术研究”;西藏自治区科技厅科技重大专项(Z2016C01G01/07) 国家重点研发项目(2016YFC0402405) 国家自然科学基金项目(51379152,91647109,51679257)
【分类号】：S152.7;S153
【正文快照】： 植物根系吸水不仅取决于根系在土壤中的分布,同时还受到土壤中水、肥、气、热等多种因素的胁迫[1-4]。现有胁迫条件下根系吸水的研究方法总体可以归纳为微观方法和宏观方法两类[5-7],其中微观方法[8-10]是将根系概化为一个无限长且半径均匀的具有水分吸收特性的单根,基于土壤

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