Knowledge Management And Simulation Of Soil Compaction Effects On Root Architecture

This paper belongs to the research field of virtual plant, the knowledge management study related to simulation of soil compaction effects on crop root architecture is investigated.Crop roots are the main organ of crop for nutrient absorption and transmission, the direct organ that make use of soil resources and the important contributor of production. Good root architecture can make the utilization rate of root on soil nutrients and moisture improved. Soil compaction affects porosity and aeration of the soil, determines water and nutrient density of soil, influences the root morphology and distribution in soil and changes the root architecture. Therefore, quantitative analysis the effects of soil compaction on crop root growth and morphology, ensure the reasonable range of soil compaction, are important for crop growth regulation and efficient production.Generally, the crop roots can be divided into strainght roots, fibrous roots and flesh roots from morphological characteristics. Straight roots are composed of taproot and multi-level lateral roots. Sub roots are branched from the parent root in the positon of the a certain distance from the tip portion, and the lateral roots for each level of root meristematic in a similar percentage. Fibrous roots are only composed of lateral roots, there is no division of taproot and lateral root. Flesh roots are formed by the taproot expandation, which surface attached with some hair, and no lateral roots.This paper took straight roots (cotton), fibrous roots (upland rice) and flesh roots (cherry radishes) as the research object. Root architecture under different soil compaction was simulated and a knowledge management system was established. Firstly, according to the root topology and root architecture parameters of cotton and upland rice, a mathematical model about the relationship between root architecture and soil compaction was built. Put the model coefficients and the corresponding root architecture parameters into the database. Using the control technology, the graph image technology and C++programming to design the program of root growth and branching of the three types roots with Visual C++6.0, programming and connected to the database, established friendly human-computer interface, completed the construction of knowledge management system. When the crop name, soil bulk density and other datas are entered into the system, the corresponding three dimensional visualization graph and numerical simulation results of the roots will be outputed.Then, got the architecture parameters of cherry radish under different soil compaction by experiment. According to the geometric model of root architecture, the radial growth model of cherry radish was established with Newton interpolation. The visual simulation of the flesh root cherry radish dynamic growth under different soil compaction was carried on.In order to verify the feasibility of the system, compare and analyze the results of simulation and cultivation experiments. The results show that:(1) Cubic polynomial fitting can quantitively expess the relationship between soil compation and root architecture parameters.(2) The extended simulation model has a certain generality, three-dimensional simulation results can vividly simulate the root architecture of straight roots, fibrous roots and fleshy roots under different soil compaction.(3) The system is able to predict the crop roots dynamic growth under the cercain soil compaction, realizing the management, forecasting and visualization of crop root architecture knowledge.