| As China accelerates the process of building a modern and robust country,national water consumption is increasing,and water shortage has become a bottleneck limiting the sustainable development of China.As a traditional agricultural country,the total water consumption in agricultural irrigation accounts for about 70% of the freshwater resources available in China,so water-saving irrigation technology needs to be vigorously developed and promoted.Aiming at the problem of low water utilization efficiency in China’s fertigation irrigation process,this paper takes the fertigation machine irrigation system as the research object and realizes watersaving irrigation decision generation and additive irrigation to the dense root zone by designing the fertigation machine layered irrigation device and its system.This device and its system are significant in improving irrigation water utilization efficiency.The primary research of this paper is as follows:(1)Introducing the concept of soil layering and the concept of three-dimensional depth and time domain of dry-depth-time theory,combined with the multi-source information fusion method,a new method of water saving by layered irrigation based on root distribution of fertigation machine is proposed to avoid the water not penetrating the root system and the water not matching the root density.(2)Fluent simulation software was used to simulate the flow rate at the main outlet of the layered irrigator with different chamber structures.The simulation results were analyzed to obtain the influence levels of seven geometric parameters.The multi-objective gray wolf algorithm(MOGWO)was used to optimize the geometric parameters of the layered irrigator with multiple objectives,which improved the irrigation performance of the layered irrigator to meet the demand of additive irrigation to the dense soil layer of a root system.(3)The root system prediction model was constructed,the measurement index and its measurement method were determined,the input and output factors of the model were selected,and the prediction model was combined with the XGBoost algorithm to provide root system information for irrigation decisions.Determine the information fusion method based on D-S evidence theory for determining whether to perform irrigation.Design a fuzzy selection strategy to determine layered irrigators’ inlet flow rate and irrigation duration based on fuzzy rules.Complete the water-saving irrigation decision modeling.(4)Hardware selection is based on the system’s functional requirements and the irrigator’s characteristics.Based on the QT Designer platform combined with the pyside2 library for fertigation machine layered irrigation system development.Realize soil and crop root condition layered monitoring and data processing,analysis,storage,and query functions.It is convenient for agricultural personnel to understand the condition of farmland and crops quickly.(5)Build an experimental platform for the layered irrigator and its system for the fertigation machine.Conduct root system experiments to provide training and test samples for the root distribution prediction model and perform error check analysis.The simulation results of the layered irrigator are validated,and the flow rate test of the layered irrigator with MOGWO multi-objective optimized geometric parameters is conducted.The system’s functions,such as root-dense soil layer determination,water-saving irrigation decision,and additive irrigation to the root-dense soil layer,are tested.The test results show that the waterfertilizer stratified irrigator and its system can effectively improve the irrigation volume and irrigation water utilization efficiency of the root-dense soil layer,thus achieving the purpose of water-saving irrigation.The test results show that the irrigation device and its system can effectively increase the amount of irrigation water in the root-dense soil layer and improve the efficiency of irrigation water utilization,thus achieving the purpose of water-saving irrigation. |
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