中文摘要：

营养液的合理调配，对促进植物早熟、生长，抗干旱，防虫害具有重要意义．本文根据营养液和植物生长规律的关系，建立了营养液浓度一植物生长量的数学模型．通过比较原理，得到模型有界正解的存在性，进而利用特征值法、Liapunov函数法对模型的动力学特性进行分析．证明了模型平衡点的存在性，并讨论其稳定性，得到系统正平衡点的全局稳定性，为现实的无土栽培管理提供理论依据．

英文摘要：

Reasonable allocation of the nutrient solution, there ie the great significance of promoting of plant early-maturing, growing, resisting drought, anti-insect. In this paper, accord- ing to the relationship of nutrient and tile growth of plant, we establish a mathematical model for nutrient-plant. Through the comparison principle, the existence and boundedness of positive solutions are obtained. And then dynamic characteristics of tilt model are analyzed, using eigen- value method and Liapunov function method. The existence and stability of equilibrium point are discussed,and the globa.1 stability of positive equilibrhurn point is obtained. Tile results of the paper provide the theory basis for realistic soilless cultivation management.