Key Technology On Variable Rate Application System

In this study, many ideas and methods such as variable operations, electromechanical integration control, sensor signal acquisition and processing, systematical analysis and integration were used. The fertilizer machine allows for variable application of three different fertilizer was designed. On this basis, variable fertilizer operating control system was developed. By the system static calibration tests, dynamic tests and field trials, the system control accuracy was analyzed. After doing research of sampling strategy, the soil was sampled reasonably and then a prescription map was generated. Variable fertilizer operating system was used to do the actual field work according to the prescription map, and a comparative analysis of operating results was done with conventional fertilization. Main results are as follows:1. According to crop demand for three main fertilizer nitrogen, phosphorus, potassium, the variable fertilizer device which has three separate manure containers was designed. The three fertilize axises can be independently controlled, so the different fertilizer in three manure containers can be fertilized in accordance with the different ratio.2. A program about using the servo motor to control the fertilize axis based on the weighing of fertilizer was proposed. The servo motor control system was processed and trial-produced. A variable manure fertilization control system and equipment forward speed detection module were designed and developed. Performance test on the institutions of the servo motor control system was done. The results showed that:Controlling the motor speed has a significant effect of fertilize performance. For the three granular fertilizer as urea, diammonium phosphate and potassium sulfate, the fertilizing amount increased linearly with the fertilize axis speed increase. That means changing the motor speed is an effective measure to adjust the fertilizing amount. Experiments were done to test the servo motor control accuracy. The results showed that: When the fertilizer measured value reaches the preset fertilization value, the variable manure fertilization controller can control the motor automatically stops running, and fertilization accuracy≥95%.3. The embedded agricultural airborne operations control terminal equipment which taking the Atom motherboard based on X86architecture as the core, integrating storage, display, input and output peripheral features and extending the CAN bus communication interface was developed. In accordance with the design of object-oriented thinking, combined variable fertilizer operation control system needs, the variable fertilization control software was designed and developed. The remote data management platform based on Spring3.0MVC framework was developed. Through the network to access the data management platform, users can learn about the mechanical operation of agricultural operations and information.4. Through the analysis of the sampling density factors, combined with the condition of plots, an appropriate soil sampling strategies was developed in accordance with the10m*10m interval grid sampling. After doing routine analysis of soil nutrient data, from the mean we know that the test plots nitrogen content than high-volume index (150mg/kg), is one fertility level; available phosphorus fertility level is two (20-40mg/kg); potassium content is low, for the six fertility levels (<30mg/kg). See from the coefficient of variation, the coefficients of variation of nitrogen, available phosphorus and potassium are all not high, belong to the moderate degree. It indicates that the nutrient content of the test plots is relatively stable. The Kriging method was used to do optimal valuation of unmeasured point parameter values, and then the ArcGIS software was used to plot. A nutrient content map in the space of the field was getted. According to the corn and soy fertilization direction of hongxing farm given by heilongjiang agricultural reclamation, combining with the soil nutrient distribution data, fertilization guidance prescription was concluded, and a variable fertilizer fertilization prescription map was generated.5. Variable manure fertilization operating system was used to do the field operation test. The fertilization experiments selected nine different fertilizer levels and different N, P, K fertilization ratio. Various fertilization errors are relatively low, each fertilizer box control precision of the fertilization ratio is more than90%. Those fertilization experiments were done repeatability. The results showed that the average error of each fertilization test were relatively low, the coefficient of variation was not large. Variable fertilization experiments of soybeans and corn were done in Heilongjiang Hongxing Farm. Accordance with the method of variables fertilization we growed corn area of1.89hectares and planted soybean area of10.23hectares. Fields in the same place, in accordance with the conventional cropping patterns, we planted soybean area of10hectares and planted corn on the remaining area. The diammonium phosphate and potassium sulfate fertilizer amount according to the precision agriculture variable fertilization method were slightly higher than the conventional fertilization amount, but the application rate of urea basic saved half. The soybean total output was41,860pounds, the yield was2045.9kg/ha on the precision agriculture variable fertilization mode. The soybean total output was38,880pounds, the yield was1997.9kg/ha on the conventional fertilization mode. The corn total output was24,630pounds, the yield was9735.2kg/ha on the precision agriculture variable fertilization mode. The corn total output was80,770pounds, the yield was8905.2kg/ha on the conventional fertilization mode.