Development of 2nd Prototype and Performance Test of Variable Rate Granular Applicator for Paddy Field with Precision Farming Concept

Abstract

The development of variable rate granular applicator for paddy field has been started since 2010 by Azis and 2011 by Sapsal. The machine based on modified riding type paddy transplanter tractor equipped with electronic controlled fertilizer applicator. It has ability to perform variable rate on dose of application using urea, phosphor, and NPK compound. The developed variable rate applicator (VRA) equipped with digital controlled metering devices so that the dose of application could be given accurately and the amount of application could be changed in flexible way according to recommended dose. The machine has 4 units of metering devices, has 8 application rows, and equipped with pneumatic diffusers. RTK-DGPS was used to monitor the position of the VRA in the field. Performance tests had been done for several parameters, included uniformity of air flow at each diffuser, granular fertilizer spreader pattern, and linearity of actual amount of fertilizer with respect to the commanded dose. Average rate of air flow in each diffuser was 0.0073 m3/s, with 7.23 % CV. Total working width of the machine was about 5 m. Field capacity was about 0.94 ha/hour on 750 m2 paddy field and 1.13 ha/hour on 1200 m2 paddy field. The results of the tests on metering dose showed that the develop VRA could spread fertilizer uniformly and gave accurate application dose. The yield result showed that uniformity of unhulled rice production was reached 74.7%