【摘要】 针对东北春玉米底肥过量、中后期缺氮的问题,应用精准变量追肥作业思想,使用GreenSeeker光谱仪,通过诊断玉米个体的NDVI值来确定最优追肥模型,区别推荐氮肥用量;通过应用单片机、GPS、数据存储卡、TFT LCD触摸屏、车速检测、步进电机驱动板、步进电机和排肥器等器件,设计一种基于NDVI值、带GPS定位、LCD交互及数据存储功能的东北春玉米的精准变量追肥系统;该系统采用一主一从双单片机分组处理数据和决策实施的控制方案。选用尿素作为测量对象进行单片机脉冲频率(Hz)与步进电机排出重量(kg)试验,结果表明两者呈线性关系,R2为0.999 4(p<0.01),通过应用追肥模型,计算出不同NDVI值下的理论追肥量,与实测追肥量作相关性分析,得到理论值(kg)与实测值(kg)之间呈线性相关,R2=0.983(p<0.01)。更多还原

【Abstract】 Aiming at the problems of excessive fertilizer and late nitrogen deficient of northeast spring corn,a control system of variable rate fertilizer applicator based on NDVI value,with GPS,LCD interface and data storage function was designed.Variable rate fertilizing thought and GreenSeeker spectrometer are applied,different amount of nitrogen fertilizer is recommended by optimal fertilization model which determined by diagnosing the NDVI value of corn individually.MCU,GPS,micro SD card,TFT LCD touch screen,speed detection,step stepper motor driver board,stepper motor,fertilizer discharger and other devices are also used in the system.The designed system adopts the control scheme with a master and a slave MCU which could deal with packet processing data and separate making decision.The relationship between MCU pulse frequency(Hz)and the step motor exhaust weight(kg)was tested by measuring urea and appear a linear relationship,R2 is 0.999 4(p<0.01).The correlation analysis between the theoretical value(kg)under different NDVIand the measured value(kg)was conducted by applying fertilizer model which get a linear and R2 is 0.983(p<0.01).更多还原