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: Desain dan Pengujian Prototipe Mesin Pemupuk Butiran Laju Variabel Empat Baris untuk Pertanian Presisi
Abstrak: In conventional method, fertilizer is applied at a uniform dosage for all location of a field. However, each location within the field needs different amount of fertilizer according to the soil nutrient content and growth condition of crop. For that purpose, it is important to develop a fertilizer applicator that allows a prescribe rate of fertilizer to be applied at each location within the field, based on recommended dose. The objectives of this research were: 1) to design digital metering system to control the application rate of a variable rate granular fertilizer applicator, 2) to develop a prototype of 4 rows granular fertilizer applicator, that can provide prescribe application rate automatically, and 3) to obtain field performance data of the prototype. A prototype of the variable rate granular fertilizer applicator was designed and constructed.The metering device consisted of two fluted wheel type of rotors which was driven by controlled DC-motor. To provide a prescribe rate of fertilizer, a control system based on microcontroller DT-AVR ATmega128L modul was developed and set to control the speed of the rotor. The prototype then was tested using three types of granular fertilizers (Urea, SP-36 and NPK), on stationary test and field tests. The stationary test result showed that the PID controller could control and provided a proportional correlation between application rate and rotor speed. The field performance test result showed that the designed prototype could provide a proper predetermined application rate of fertilizers precisely. The average deviations of the application rate for 50, 100, 150, 200, 250 kg/ha dose of Urea were -1.67 , 3.33, 0.28, 2.71 and 1.33 % respectively. For SP-36 were -21.67, -5.42, -2.47, -2.71, and -1.67 %. respectively. For NPK were -18.33, -4.17, -4.17, -3.75 and -2.33 % respectively.
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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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