| After years of innovation and development, precision agriculture technology do not develop go hand in hand. Especially in the current agricultural scale operation mode based on water saving irrigation technology(drip irrigation), precision fertilization technology achievements are mainly concentrated in the monitoring of crop nutrients and soil nutrient, fertilizer rate, yield, soil nutrient distribution, integrated water management and other aspects of the research. In precision fertilization link, however, there was no efficient technical solution to solve the current all kinds of technical problems in fertigation equipment field. A short board of precision agriculture technical equipment will finally affect the realization of the intensive management and control of precision agriculture technology under the condition of current agricultural scale operation.At present fertigation link uses pressure differential tank as technology equipment. The equipment is used until today since the drip irrigation technology was introduced into our country. But with the needs of the development of precision fertilization technology constantly, many scholars researched on information monitoring, information transmission, data analysis and decision of fertigation nutrient over many years, and formed many theoretical achievements. But because the current application execution device, namely the traditional pressure differential tank is extensive and factitious, so the recommend fertilization decision-making conclusion can’t transfer through information technology, also it’s unable to express through automation control technology. This makes the fertigation implementing link technology and equipment research and development becomes a pressing problem.And now the problems of fertigation links are:(1) fertilizer rate cannot be accurately controlled according to the requirements of wheel irrigation and crop;(2) fertilizer concentration is high at first but low at last, uniformity is low and easily affected by differential pressure and flow influence;(3) due to the fertilizer injection evenness, fertilizer injection time can’t control;(4) fertilization link completely by artificial operation, unable to realize automation control.This study integrated application of information technology, electromechanical integration control, system integration, nutrition diagnosis, and field trials comparing technology thought and method, to design irrigation precision control fertilization device which can realize irrigation fertilizer accurate control, overall fertilizer injection well-distributed, fertilizer injection time can be controlled, and using the information technology, developed the drip irrigation precise fertilization control system, including locale and remote control function. This paper through the analysis of the existing equipment, finally designed the fertigation device that can meet the needs of the current drip fertigation, and accomplished automatic control. Through the device control system monitoring, capacity analysis and fertilization pattern research, completed from the device design idea to the field actual operation of each work. And formed the following results:1. According to the problems of fertigation links put forward the design idea and principle of drip irrigation precise control fertilizing device, and analyzed the fertilizer characteristics of existing device, keep its advantage and improve defect. We put forward the research design of preparation mechanism aim at the fertilizer rate accurately controlled; And we put forward the research design of quantitative repeated small injection mechanism aim at injection evenness. Completed the design and assemblage of the drip fertigation precise control device. Meanwhile, To carry out the test of definition and uniformity distribution fertilizer. Certification the superior application performance of this device.2. We developed irrigation fertilization device control and remote control system based on the PLC and put forward the drip irrigation precise control fertilization system field control technology solutions and remote control technology. Field control adopted the text display to show the equipment operation parameters, and by manual to input application link parameters to control precision fertilization. Meantime we designed and researched the stepper motor and linear motor drive mode. Through programming and software development, finally accomplish the automation control.3.Used independent research and development drip irrigation precise control of fertilizer equipment as the research object, through the best nitrogen application at different development stages, single irrigation time and irrigation area of drip irrigation cotton based on SPAD nutrition diagnosis, we researched the single fertilization time of precise fertilization devices with different specification fat dish, confirmed preparation ability under different irrigation conditions and different growth period of drip irrigation precise fertilization device. Finally it provided theoretical basis for the improvement of fertilizer distribution system agencies and optimization of parameters.4.We carried out fertilization experiment in drip irrigation cotton fields of two kinds of device(precise control of fertilizer fertilization system time fertilizer, precisely controlled differential cannot be achieved) in different growth period of cotton and different irrigation times, through experimental analysis of nitrogen distribution in soil, cotton nitrogen utilization and cotton production under two case of fertilizing test, to show the superiority and fertilizer effect of fertilization control system, and proved the best fertilization mode according to the different growth period of cotton in irrigation link.Through the research of the design of the device and driving equipment selection study, this study completed the drip precise control fertilizing device independent research and development. Through the irrigation fertilization device control and remote control system based on the PLC accomplish automation precise fertilization, fertigation quantitative control, automation and fertilization time control, significantly improved the injection evenness of fertigation link. Based on the research of the fertilizer ability, we determined the best nitrogen fertilizer rate of cotton Cheng Lei period, flowering and blooming period are: 63.03 kg/hm2, 64.19 kg/hm2, 60.09 kg/hm2, 62.84 kg/hm2, providing theoretical basis of variable rate fertilization at different development stages of drip irrigation cotton. And through the research it showed that there is no relation between nitrogen application rate per unit time and head flow qd, but relate to water yield Q and nitrogen application Nd of particular cotton growth period. Finally we acquire the drip irrigation improvement project of precise control fertilization equipment. Through fertilization effect contrast test between independent research and development fertilization equipment and the traditional differential fertilizing device of drip irrigation cotton, based on cotton yields, proved the best fertilization period of the different growth period of cotton according to irrigation precision control system. |
PDF Full Text Request