FEASIBILITY OF PRECISION FARMING FOR GRASSLAND AGRICULTURE

本研究探讨了草地精耕细作的可行性。（草地田间信息系统）在附养场的草地上提供了4处0.5 ha的试验田。试验草地第一次和第二次刈割的产量图具有相似的趋势。土壤表层至5 cm深度的硝态氮浓度较高（平均210 mg/ 1in），但pH值与地表一样低。两者与产草量的相关性均较低。在半方差分析的基础上，对数据采集间隔进行了检验，以估计合适的产量映射系统。利用124个窗口的产量估算出试验草地产量的最佳数据采集间隔小于10 m。（草原管理导航系统的研制）DGPS接收机使用导航系统时的工作运行精度为0.4 m。利用GPS的三维位置信息进行测量后，就可以制作出等同于常规测量的等高线地图。利用导航系统的功能，进行了施肥制图，对比了1号草的施肥制图和产量制图，几乎没有发现喷施斑点对草产量的影响。（利用传感器融合技术开发拖拉机自主行驶系统）研制了DGPS接收机、雷达测速仪和陀螺仪相结合的拖拉机自主行驶系统。经草地边运行检测，直线运行部分运行偏差在0.3m以内（采样周期0.5s，速度0.3m/s）。随着工作人员意识的改变，通过对拖拉机运行轨迹和产草量的可视化，促使农场提出了提高工作精度的一系列建议。此外，通过试验生产系统，可以预期以精准农业为目标的新型农场管理的可行性。

This study investigated feasibility of the Precision Farming for grassland.(Field information system for grassland)Test field of 0.5 ha in amount in four places was provided into the grass field at the attachment farm. The yield map of the tested grassland between 1st and 2nd grass cutting had the similar tendency. The nitrate nitrogen concentration at the ground surface to 5 cm depth was high (210 mg/ 1in average), but pH was as low as the surface. In both, correlation with grass yield was low. Data acquisition interval was examined to estimate the appropriate yield mapping system based on Semi-variance analysis. Optimum data acquisition interval on yields of the tested grassland was estimated less than 10 m using the yield of 124 windrows.(Development of navigation system for the grassland management)The work running precision when using navigation system by the DGPS receiver was 0.4 m. After measuring using the position information of the 3 dimension of GPS, the contour map that is equal to conventional survey could be made. Using the function of navigation system, manure-spraying mapping was made, After comparing manure spraying mapping and yield mapping in the 1st grass, an influence of spraying speckles on grass yield was hardly seen.(Development of tractor autonomous running system by the sensor fusion)Tractor autonomous running system, which combined DGPS receiver, a radar speedometer and a gyro, was developed. After examining in the running by the grassland, the straight line running part could be run within the 0.3 m deviation (sampling period 0.5s, speed 0.3m/s).A series of overtures on the farm prompted for the improvement of the work precision by the visualization of a tractor's running trace and grass yield as the consciousness of the work member changed. Moreover, by using an experimental production system, feasibility of new farm management, which aimed at the Precision Farming, could be expected.