Judul: Pengembangan Prototipe II dan Uji Kinerja Mesin PemupukaDosis iaiVariabeli(Variable Rate Granular Applicator) pada Budidaya Padi iaiSawah dengan Konsep Pertanian Presisi.
Abstrak: 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%
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Judul: Disain dan pengujian metering device untuk unit pemupuk butiran laju variabel (variable rate granular fertilizer applicator)
Abstrak: Uniform rate of fertilizer applicator (URA) practice is disregarding the productive potential of the various areas within the field. Thus, some area is less fertilized and other is over fertilized. It is also an important issue recently that nitrogen from fertilizers may be subjected to lost into atmosphere or enters streams through surface or subsurface drainage (leaching). The place with overfertilization will be a potential source of pollution in the form of ammonia (NH3), nitrite (NO2) and nitrate (NO3) which may hazard people health. Therefore, a contemporary issue is how to give an effective dose at the accurate position and right time for optimum growth of crops while preserving the environment without causing economic losses. Variable rate of fertilizer applicator (VRA) is a solution to overcome the negative impact of URA. It can control the appropriate of fertilizer dosage and location of application in the field. The objective of this research is to design a metering device for variable rate granular fertilizer applicator. In this research, the metering device was equipped with two rotor, which could be operated as single rotor or double rotor. The dose of granular fertilizer could be controlled by the rotation of the rotor. The rotation of the rotor was controlled using digital PID algorithm. The result of variable rate fertilizer testing of the metering device using single rotor indicated that the rate of urea, SP- 36 and NPK are 0.84, 0.96 and 1.2 g/rotation respectively. The testing using double rotor indicated that the rate of urea, SP-36 and NPK are 1.14, 2.22 and 2.1 g/rotation respectively. All results showed that the prototype of metering device can control fertilizer dose of urea, SP-36 and NPK fertilizer precisely.
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Judul: Embriogenesis ikan buta (Astyanax fasciatus)
Abstrak: Ikan buta Astyanax fasciatus adalah spesies ikan unik dari famili Characidae yang menempati perairan dalam gua di Wilayah La Cueva Chica-San Luis Potasi-Mexico. Ikan ini memiliki mata yang tereduksi (Blind Cavefish) dan warna kulit merah muda, pucat serta mengkilap.
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