Development of Grooved Belt Type Fertilizer Metering Mechanism for Spot Fertilizer Applicator

Higher risks involved in excess fertilizer application require precise placement of fertilizer in adequate amount in the root zone of the crop. The drawbacks of current fertilizer application techniques (band placement, pellet application, and ring basin method) include over-fertilization, soil acidity, nutritional imbalances, soil structure damage and an increase in bulk density. Development of a spot fertilizer applicator with precise fertilizer metering was planned to address the problem. The physical and mechanical properties of di-ammonium phosphate were determined. A new grooved belt type fertilizer metering mechanism was developed for orchard application using the fertilizer properties determined. The metering mechanism was equipped with a fertilizer box of 100 kg capacity. The torque requirement of metering mechanism was determined using torque transducer to select a DC motor. The maximum torque required was 4.5 N.m at 8 m.min-1 of metering belt speed. An automatic plant detection-based spot fertilizer applicator with developed fertilizer metering mechanism has potential to save about 20% fertilizer compared to band placement along with reduced labour requirement.