风送式水稻侧深精准施肥装置的设计与试验

针对中国水稻施肥机械化程度低,传统撒施肥料利用率低、施肥量大的现状,结合侧深施肥农艺特点,对风送式排肥方法进行了理论分析,研制了风送式水稻侧深精准施肥装置。该装置采用模块化设计与乘坐式插秧机配套使用,采用电机驱动排肥、风送肥料、全球定位系统(global position system,GPS)测速的工作原理,侧位深施化肥的施肥方式,采用车辆行驶速度与排肥驱动电机转速实时匹配的精准施肥控制方法。设备在黑龙江七星农场开展了田间实际作业试验。试验表明,该装置与插秧机配合使用时能一次性完成插秧与侧深精准施肥作业,当预置施肥量为300 kg/hm2,车辆稳定行驶速度为1 m/s时,施肥量偏差控制在5.82%以内,能够较好的满足实际生产需求。该研究为开展水稻变量施肥控制技术研究和水稻侧深施肥装置的研发提供了参考。

Design and experiment on air-blast rice side deep precision fertilization device

Abstract: Rice is the most important crop in China, which has the largest plant area, the highest per unit area yield and the most total output. Fertilization is an important process of rice production, which directly affects the yield of crops, and reasonable and effective use of chemical fertilizer can improve the yield of crops. At present, the mechanization level of rice fertilization is very low in China, and the artificial fertilization with a large amount of fertilizer causes the uneven distribution of fertilizer. The side deep fertilization for rice is an ideal way of fertilization. The fertilization device will apply fertilizer (basal and tiller fertilizer) quantitatively and with one-time positioning based on the agronomic requirements, and it can carry out a uniform fertilization to the rice's side position with a certain depth, which can reduce nitrogen fertilizer amount of 20%-30% compared with the traditional fertilization operation. It is a cultivation technique with high output, stable yield and low cost. In view of the low-level mechanization of rice fertilization in China, the large amount of fertilizer application and the low fertilizer utilization in the traditional manual fertilization, combined with the agronomic characteristics of side deep fertilization, we analyzed the fertilization method of wind delivering and developed the air-blast rice side deep precision fertilization device. This device adopted the modularization design and was combined with riding type rice transplanter for use. In the process of operation, the fertilizer granules fell into the deep trench with a certain amount under the effect of gravity and wind; the trench with 5 cm depth was dug by fertilizer exports at the position 3 cm away from seedling side, and the fertilizers would be covered in the mud by covering plate. The device used the rated voltage of 12 V and the power of 72 W; the blower was used to transport fertilizer based on the Venturi effect, and the inner diameter of fertilizer conveying pipe was 25 mm and the velocity was 21 m/s; the global position system (GPS) was used to measure transplanter speed. The speed of the vehicle was proportional to the speed of the motor by using the precision fertilization control method, which could match the vehicle speed and drive motor speed in real time. The speed measurement closed-loop control was used as the control system. Motor drive used the AQMD2410NS direct current motor drive, and motor hold a stable speed by using the internal drive integration of the proportion-integration-differentiation (PID). The vehicle control terminal was designed under the embedded Visual C++ integrated development environment in the XP Windows operating system, the interface could display the current operating data, and meanwhile, the user could set the working parameters according to the actual operating requirements. When presetting fertilization amount to 300 kg/hm2, the motor rotation speed was 10, 20, 30 and 40 r/min, respectively. The fertilizer difference test with 6 fertilizer discharging ports was carried out, and the coefficients of variation of fertilizer application amount were 2.3%, 2.1%, 2.2% and 1.8%, respectively. The experiments were conducted on Heilongjiang Seven-star Farm, and the result showed, planting and fertilization could be done completely and independently in one time when fertilization device and riding type rice transplanter operated. When the preset rate of fertilization was 300 kg/hm2 and the vehicle speed was 1 m/s, the fertilization device could realize the precision fertilization, and the deviation of fertilization application amount was within 5.82%, which could meet the requirement of the actual production. The research provides reference for the development of the rice variable fertilization control technology and the research and development of the rice side deep fertilization device.