【作者】 庄卫东；

【导师】 汪春；

【作者基本信息】 黑龙江八一农垦大学 ， 农业机械化工程， 2011， 博士

【摘要】 随着农业现代化的发展,为了生产环境和经济的可持续性,产生了精准农业。基于农田空间差异的变量施肥播种技术是精准农业技术的重要组成部分。本研究根据东北黑土漫岗区坡耕地因多年耕种形成的自身特点,结合大豆农艺研究成果,针对大规模生产大豆精准生产的需求,开展了黑土漫岗区坡耕地空间变异研究,农田三维地形测绘技术研究,变量控制硬件系统研制,开发变量控制软件,对传统精密大豆播种机进行改装,田间大豆变量施肥播种试验。对适合我国东北黑土漫岗区大豆变量施肥播种生产的技术进行了探索。本研究的主要内容和成果有以下几个方面:1.进行了黑土漫岗区坡耕地空间变异研究。使用了SPSS Statistics 17.0、MATLAB R2009a、AFS 5.02等工具软件。对红星农场试验地块的高程、碱解氮、速效磷进行了基本统计分析、正态分布检验、相关性分析,发现该试验地块的高程和土壤碱解氮呈现显著的正相关。在嫩江县试验地块进行了土壤GPS定位取样,对试验地块的碱解氮、速效磷、速效钾、pH值、有机质进行了基本统计分析、正态分布检验,作出了Q-Q概率图和频率分布直方图。通过相关性分析表明,土壤有机质与碱解氮呈极强的正相关(r=0.498,P<0.01),地块的高程和土壤碱解氮呈正相关(r=0.253,P<0.05)。制作了试验田高程图,碱解氮、速效磷、速效钾、pH值、有机质的分布图。得出黑土漫岗区坡耕地的高程变化与土壤碱解氮的分布有相关性,坡耕地农田地形与土壤水肥分布有相关性的结论。2.进行了农田三维地形测绘技术的研究。通过需求分析认为对于坡耕地三维地形的地块高程数据的精度在亚米级即可满足需求,选用了AgGPS 332接收机,免费接收MSAS2的卫星差分信号后,定位精度达到亚米级。坐标变换采用了UTM投影。开发设计了车载三维地形测量系统,进行了直线行走导航算法研究,制作了导航光耙,开发了导航软件,满足了田间测绘导航的需求。使用小波变换的方式进行了三维地形测量数据处理,研究表明在农田三维地形测绘中,对DGPS连续测得的高程值使用db6小波进行5层分解消噪后,进行坡耕地的三维地形曲面的构建,适用于黑土漫岗区坡耕地具有的较缓的波状起伏,可以很好地反应农田的地形地貌特征。3.进行了变量施肥播种机变量控制系统的硬件结构设计。选择了车载计算机,并对其配备的GPS模块进行了动态定位测试。选择了U34-0.75型脉动式机械无级变速器作为变量系统的主工作部件,并对其进行了电控改装。对变量控制器进行了设计,采用了闭环控制方案和双路H桥直流电机驱动模块,使用AT89C52单片机为主控芯片。进行了试验台测试,得出了电控无级变速器传动比与指令之间的回归曲线方程,电控无级变速器输出轴回传值与转速之间的一元线性回归方程。为精准农业变量施肥播种提出了新的硬件解决方法。4.进行了变量控制软件设计。研究了控制指令的算法并给出了算例。提出了使用地块平均施肥量、设定变量范围、根据施肥处方图的控制值大小来进行精准变量施肥控制的简易方法。分析了实时施肥量的算法。根据系统转速信号的特点,设计了的复合多级数字滤波器,对快速变化的信号及有脉冲干扰的信号都能获得较好的滤波效果。开发了精准农业变量施肥播种系统软件。软件开发使用VB6.0编程语言及MSComm串口通信控件和MO2.2地理信息控件和Access2000数据库。处方图的形式采用了广泛使用的shape文件格式。软件能自动生成作业记录,机组正常行走作业时,每2秒记录1次数据,同时可实时显示开始作业以来的作业长度和作业面积。设计了记录图显示和作业回放功能,利于用户对变量施肥作业记录信息的使用和生产追溯。5.进行了田间变量施肥播种试验。进行了变量施肥播种机改装与调试,对播种系统传动比进行了计算,用于实际播种量的检查与调整。对排肥系统的传动进行了设计,在播种机的排肥传动系统中加入电控无级变速器,使排肥系统的总传动比可在1.89～3.77的范围内变化,从而能做到变量施肥和在定量施肥时对施肥量能进行快捷调整。对改装的播种机的施肥量进行了调试,使播种地块的农艺决策平均施肥值在播种机最大施肥量和最小施肥量的中值附近,保证可靠控制变量施肥。根据大豆栽培农艺需求和土壤养分的相关性,对高程数据进行正线性相关无量纲化处理,对有机质数据进行负线性相关无量纲化处理,用两者无量纲的平均值作为处方图的决策值,生成了混合肥的施肥处方图,实现了根据地块空间差异变量配方平衡施肥。试验地块施肥量变量范围确定为±5%,地块施肥量变化范围为213.75～236.25 kg/hm~2。通过田间播种试验表明,研制的变量施肥控制系统使用方便、工作稳定、变量控制可靠、效果良好。更多还原

【Abstract】 Abstract: With the development of agricultural modernization, in order to ensure the environmental and economic sustainability, precision agriculture has emerged. The variable rate fertilizing and seeding technology is an important component of the precision agriculture based on field spatial variability. The slope land of the black soil gentle hilly regions of the northeast China cultivated for many years formed their own characteristics, combined with agronomic research and large-scale production of soybean accurate product demand, research work carried out including spatial variability of slope farmland, land three-dimensional topographic mapping technology, variable control hardware systems research and development of variable control software, the traditional soybean planter be modified, soybean variable rate fertilizer application and seeding experiments in fields. The variable rate fertilizing and sowing techniques are explored, which is suitable of black soil hilly areas soybean production. The main contents and results in the following areas:1. Study on the the black soil gentle hilly regions spatial variability of slope land. Using the SPSS Statistics 17.0, MATLAB R2009a, AFS 5.02 software and other tools, elevation, available N, available P of experimental field in the Hongxing Farm were descriptive statistics analysis, normality test, correlation analysis, found that the land elevation and soil available N showed a significant positive correlation. GPS positioning and soil sampling conducted on experimental field in Nenjiang County, available N, P, K, pH, OM were basic statistical analysis, normality test, made a Q-Q probability plots and frequency distribution histograms. The correlation analysis indicated that soil OM and available N was strong positive correlation (r = 0.498, P <0.01), land elevation and soil available N was positively correlated (r = 0.253, P <0.05). Experimental field elevation map, available N, P, K, pH, OM distribution were produced. The results show that slope farmland’s elevation in the black soil gentle hilly regions and the distribution of soil available N is correlated, the topography of slope farmland correlate with distribution of soil water and fertilizer.2. Three-dimensional topographic mapping conducted techniques. Through needs analysis that the elevation data of sloping land terrain in the sub-meter accuracy can meet the demand, the choice of the AgGPS 332 receiver which free receive MSAS2 satellite differential signal and achieve sub-meter positioning accuracy. The UTM projection was used for coordinate transformation. The vehicled 3D-terrain measuring system was developed, straight line navigation algorithm was given, a navigation light bar was produced. The software was developed to meet the needs of the field mapping navigation. The wavelet transform was used for 3D-terrain survey data processing, research shows using a db6 wavelet 5 level decomposition denoising for elevation data measured by DGPS continuously was suitable for the 3D-terrain farmland surveying and mapping in black soil hilly area which farmland have the more moderate wavy. Farmland can be a good response to topography features.3. The variable control system’s hardware architecture was designed for variable rate fertilizer planter. Select a on-board computer which equipped GPS module was tested for dynamic positioning. Select the U34-0.75 type mechanical impulse stepless speed variator as the main working parts, and modified it for the electronic control. The variables controller was design by using a closed-loop control scheme and the dual H bridge DC motor driver module, using AT89C52 micro-controller as the master chip. Experimental test was conducted and regression curve equation was obtained for electronically controlled CVT transmission ratio and instruction, the linear regression equation between output shaft speed and the return value. The new hardware solution was proposed for variable fertilizing and seeding of precision farming.4. The design of variable control software. The control instruction algorithm and example were studied. Simple methods for accurate variable rate fertilizer control have been proposed that the use of average fertilizer of field and set the variable range, accurate control variable rate fertilizing based on control value of fertilizer prescription map. The real-time fertiling algorithm was analysised. According to the characteristics of the system speed signal, multi-level complex digital filter is designed which can get a better filtering effect for the fast-changing signals and a pulse interference signal. The variable rate fertilizer seeding software for precision agriculture is developed. Software developed using VB6.0 programming language and MSComm serial communication control and MO2.2 geographic information control and Access2000 database. The shape file format is used which is widely form in Prescription map. Software can automatically generate operating records. When sowing machine normal operation, every two seconds record one set of data, real-time display length of operation and operating area since the job beginning. The record showing and operations playback function is designed, which will help users to use record information and production traceability.5. The experiment of variable rate fertilizing and seeding was implemented in the field. Variable rate fertilizer planter was modified and debuged. The transmission ratio of the seeding system was calculated for the actual amount of the check and adjustment of planting. The transmission of fertilizer system was designed that add a electric continuously variable transmission in the planter, the total ratio of fertilizer transmission system can be changed beween 1.89 to 3.77, which can be variable rate fertilization and the quantitative amount of fertilizer can be quickly adjusted. The fertilizer of planter was modified, so that average value of agricultural decision-making fertilizer could be around the median of the planter maximum and minimum fertilizer, to ensure reliable control of variable rate fertilization. According to soybean cultivation agronomic demand and soil nutrient relevance, the elevation data is processed by positive linear related dimensionles, the OM data is processed by negative linear related dimensionles, with the average of the two data as a prescription decision values to produce a mixed fertilizer prescription map to achieve the variable rate fertilization based on field spatial variability. The scope variable is±5% of experiment of field fertilization, fertilizer ranged from 213.75 to 236.25 (kg/hm2). The field experiments show that variable rate fertilizer control system developed easy to use, stable, variable control reliable, have a good effect.更多还原