PERFORMANCE OF HELICAL METERING MECHANISMS IN THE APPLICATION OF MICROGRANULAR FERTILIZER

ABSTRACT The use of microgranular fertilizers is currently increasing, with low application rates as an obstacle in the mechanization. This study aimed to verify the performance of helical metering mechanisms using microgranular fertilizer. Four different fertilizer-metering mechanisms were tested at two pre-established dose rates (35 and 50 kg ha−1) and seven longitudinal angles (−15°, −10°, −5°, 0°, +5°, +10°, and +15°). The experiment was carried out according to Brazilian standards. The results showed that the longitudinal inclination affects the actual fertilizer dose in all tested metering systems. Metering mechanisms with a helicoid with longitudinal and lateral overflow presented a similar dose, according to the variation of the longitudinal inclination. The metering mechanism with two helicoids showed the highest dose variation, while the metering mechanism with a helical thread and longitudinal overflow, filled between the shaft and the helicoid, had the best performance.

摘要：目前微颗粒肥料的应用正逐步增长，但较低的施肥量成为其机械化施用的阻碍。本研究旨在验证采用微颗粒肥料的螺旋式排肥机构的作业性能。本试验针对4种不同的排肥机构，在2种预设施肥量（35 kg·ha⁻¹与50 kg·ha⁻¹）以及7种纵向安装角度（-15°、-10°、-5°、0°、+5°、+10°、+15°）下开展测试。本试验依据巴西国家标准实施。试验结果表明，纵向倾角对所有受试排肥系统的实际施肥量均存在影响。随纵向倾角变化，具备纵向与侧方溢料结构的螺旋排肥机构的施肥量波动幅度较为接近。带有双螺旋面的排肥机构施肥量波动幅度最大；而采用螺旋螺纹且具备纵向溢料结构、填充于转轴与螺旋面之间的排肥机构则表现最优。