基于L系统的紫花苜蓿动态生长根系模型构建

Construction of Dynamic Growth Root System Model for Purple Alfalfa Based on L System Theory

摘要:

针对现有紫花苜蓿根系动态生长模型和岩土工程生态防护方面的护坡植物根系模型空缺，将传统的L系统进行改进，提出了一种基于L系统的可应用于岩土工程生态防护领域的动态生长根系建模方法。通过控制伊犁黄土干密度、初始含水率和种植环境的温湿度等，开展了紫花苜蓿种植，统计了不同生长时间下的紫花苜蓿的主根根长、主根直径、侧根数量、侧根直径、侧根长度和侧根分支点等。结合紫花苜蓿生长参数，基于L系统和建模技术，完成了紫花苜蓿动态生长根系模型的构建。结果表明：紫花苜蓿根系生长满足Logistic方程，侧根与主根夹角为15°~60°, 侧根数量、分支间距和开始分支的长度等随着生长时间增加而增加, 主根下段直径稳定在0.01~0.04mm, 靠近土壤表面的主根直径随时间变化较大；侧根直径小，直径变化也小。使用Logistic方程为紫花苜蓿根系生长模型，基于L系统结合建模技术构建了可用于数值仿真的紫花苜蓿动态生长根系模型，对该模型进行了验证，结果表明根系模型整体误差小。本文基于L系统的紫花苜蓿动态生长根系模型成功将紫花苜蓿根系的动态生长可视化，可应用于农业生产、植物学和岩土工程的数值仿真领域，为紫花苜蓿根系动态生长模型和岩土工程生态防护方面的植物动态生长根系模型建立提供参考。

Abstract:

In response to the existing deficiencies in the dynamic growth model of alfalfa root system and the root system model of slope protection plants in geotechnical engineering ecological protection, the traditional L system was improved. A dynamic growth root system modeling method based on the L system applicable in the field of geotechnical engineering ecological protection was proposed. By controlling the dry density, initial moisture content, temperature, and humidity of Ili loess, alfalfa planting was carried out. The main root length, main root diameter, number of lateral roots, lateral root diameter, lateral root length, and lateral root branching points of alfalfa at different growth times were recorded. Based on the growth parameters of alfalfa and L system and modeling technology, a dynamic growth root system model of alfalfa was constructed. The results indicated that the root growth of alfalfa followed the Logistic equation. The angle between lateral roots and main roots ranged from 15° to 60°. The number of lateral roots, branch spacing, and length of starting branches was increased with growth time. The diameter of the lower segment of the main root remained stable between 0.01mm and 0.04mm, while the diameter of the main root near the soil surface varied significantly with time. The lateral root diameter was small, and the diameter variation was also minor. Using the Logistic equation as the root growth model for alfalfa, a dynamic root growth model for alfalfa suitable for numerical simulation was constructed based on the L system combined with modeling techniques. The model was validated, and the results showed that the overall error of the root model was small. This L system-based dynamic growth root model of alfalfa successfully visualized the dynamic growth of alfalfa roots and can be applied to numerical simulation fields in agricultural production, botany, and geotechnical engineering. It filled the gap in the dynamic growth model of alfalfa roots and provided a reference for the establishment of plant dynamic growth root models in geotechnical engineering ecological protection.