除水资源短缺外，我国农业生产还将不得不面临大气CO2浓度逐年升高所带来的影响。CO2是作物进行光合作用的物质基础，其浓度的变化势必会对根系吸水产生较大影响。在CO2浓度升高条件下，根系吸水性能和根系生长都可能会受到不同程度的抑制或刺激，且这些影响都可能随作物适应时间的延长而降低甚至丧失。然而，现有根系吸水模型与根系生长分布模型都没有、也无法对其予以考虑。以大气CO2浓度升高为背景，通过布置小麦室内水培试验、土柱试验以及田间试验，本项研究拟探索并定量表征小麦根系吸水性能（单位质量根氮潜在吸水系数）与根系生长分布（根氮分配与根氮质量密度分布）所受到的影响，从而对已有基于根氮质量密度的根系吸水模型以及根系生长分布模型予以改进，并对根系生长分布、根系吸水以及土壤水分运移进行动态模拟。相关研究成果不仅可完善根系吸水与生长相关理论，还可为CO2浓度升高条件下农业水资源的高效利用提供科学依据与技术储备。

In addition to water shortage, agricultural production in China has to deal with the influence resulted from the gradually elevated atmospheric CO2 concentration. As an important substrate for photosynthesis, the change of CO2 concentration will have a number of effects on root-water-uptake. Under conditions with higher CO2 concentration, the water absorption function of roots and root growth might be limited or promoted somehow, and the effects on both of them might get smaller and even disappear with the extension of adaptation time. However, the effects were not and could not be taken into consideration by the existing root-water-uptake models and root-growth-distribution models. In this study, the effects of elevated CO2 on water absorption function of roots (the potential root-water-uptake coefficient per unit root nitrogen mass) and on root growth and distribution (the root nitrogen allocation factor and the root nitrogen mass density profile) will be investigated and quantitatively described. To achieve this objective, a solution cultivation experiment and a soil column experiment in a greenhouse will be conducted for wheat, as well as a field experiment. Subsequently, the existing root-water-uptake models and root-growth-distribution models based on root nitrogen mass density will be improved, and the dynamics regarding root growth and distribution, water uptake, and soil water transport will be simulated. The findings will not only enhance the theoretical system regarding root growth and water uptake, but also will become the scientific evidence and technical storage to efficiently use agricultural water resources under elevated CO2 in the future.