| Facility cultivation technology has become the main planting method of Tomato in China because of its controllable environment,high yield and high efficiency.As one of the key technologies of water and fertilizer regulation in facility agriculture,water and fertilizer integration technology is the guarantee for facility tomato planting to achieve "water control,weight loss and efficiency".Aiming at the problems of unreasonable fertilization scheme,low accuracy of fertilizer solution allocation and lack of control model in the current water fertilizer integration system,this study studied the decision-making of tomato fertilization and the fertilizer solution allocation model of water fertilizer integration.The main research contents include:（1）Study on Tomato fertilization decision model.In order to improve the scientificity of fertilization decision-making of protected tomato,based on the study of four kinds of mainstream fertilization decision-making models,taking the nutrient balance fertilization method as the theoretical basis and combined with the law of tomato nutrient demand,the fertilization decision-making model of protected tomato in the whole growth period was established to clarify the nutrient demand of Tomato in different growth periods;Through the fertilization level control experiment,the fertilization decision-making model of facility tomato is verified and improved.The experimental results show that the fertilization decision-making model realizes the goal of "low fertilizer and high yield" of tomato planting,and has strong practicability.The model can be used as the theoretical basis for the fertilization decision-making of facility tomato.（2）Study on control model of fertilizer and fertilization in protected tomato.In order to realize the precise matching and fertilization control of facility tomato,a fertilization control strategy of facility tomato based on controlling the EC Value of fertilizer solution was proposed.According to the characteristics of nonlinearity and strong hysteresis in the process of fertilizer liquid allocation,a control model of fertilizer allocation based on Fuzzy PID is studied and constructed.Through simulation analysis,the response time and overshoot of the optimized fuzzy PID controller are reduced by 20% and 16% respectively,which has good practicability and can provide support for accurate fertilizer blending.Combined with the fertilization decision-making model of protected tomato,the fertilization control model of protected tomato is studied and constructed,which lays a foundation for the fertilization control of protected tomato in the whole growth cycle.（3）Design and implementation of water and fertilizer integration system.In order to realize the automatic control of facility tomato water and fertilizer,an integrated intelligent measurement and control system of facility tomato water and fertilizer based on the "six domain" architecture of the Internet of things（GB / T 33474-2016）is developed.The system includes three parts: lower computer system,upper computer system and mobile app.Through the nesting of upper computer and python,the application of fertilization decision model and fertilization control model is realized,and the intelligent control of fertilization in the whole growth period of facility tomato is realized.Experiments show that the system runs stably and reliably,realizes the integrated automatic irrigation and fertilization control of water and fertilizer for facility tomato,significantly reduces the fertilizer consumption,fertilization labor intensity and labor cost of facility tomato,and increases the tomato yield of intelligent fertilization facility by 13.7%,which verifies the practicability and effectiveness of the system. |
