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: Infeksi leucocytozoon Smithi (Laveran dan Lucet, 1905) pada kalkun
Abstrak: Leucocytozoon smithi adalah parasit darah yang menyebabkan leucocytozoonosis pada kalkun, dan termasuk dalam genus Leucocytozoon yang perkembangan skizogoninya terja- di dalam sel-sel endotel dan sel-sel parenkhim hati, jan- tung, ginjal dan organ-organ lain dari unggas. Genus ini menghasilkan skizon yang besar. Gametogoninya terjadi di dalam sel-sel darah dan sel yang terinfeksi dapat berubah bentuk dan mengambil bentuk kumparan. Parasit ini tidak menghasilkan pigmen dan ditularkan oleh lalat penghisap darah dari genus Simulium. Infeksi kalkun terjadi pada saat sporozoit masuk ke dalam peredaran darah dan selanjutnya masuk ke dalam sel- sel parenkhim hati. Siklus hidupnya mirip dengan siklus hidup L. simondi seperti yang diuraikan di bawah ini. Skizogoni yang terjadi di dalam hati menghasilkan skizon hepatik. Skizon hepatik dewasa menghasilkan merozoit dan sinsitia. Merozoit dari skizon hepatik memasuki eritroblas dan eritrosit dan membentuk gametosit bulat, sedangkan sinsitianya dapat masuk ke dalam sel-sel RES dan kemudian membentuk megaloskizon. Megaloskizon dewasa menghasilkan merozoit yang kemudian masuk ke dalam limfosit dan leukosit lain membentuk gametosit memanjang. Gametositgametosit ini akan menjadi makrogametosit dan mikrogametosit. Perkembangan parasit dalam tubuh vektor (Simulium), segera dimulai setelah vektor menghisap darah kalkun yang mengandung gametosit ini. Dalam tubuh vektor ini akan ter- jadi pembuahan makrogamet oleh mikrogamet (tahap gametogoni). Dari pembuahan ini dihasilkan zigot yang bergerak (ookinet). Ookinet akan masuk dinding usus vektor untuk memulai tahap sporogoni yang menghasilkan sporozoit. Sporozoit ini akan menuju ke kelenjar ludah dan dari sini dapat dipindahkan lagi ke tubuh kalkun pada saat vektor menghisap darah. Vektor untuk L. smithi adalah S. occidentale, S. nigroparvum, S. slossonae, S. nigritarse. L. smithi berbahaya, terutama bagi kalkun-kalkun muda. Mortalitasnya dapat mencapai 90 persen. Gejala klinis yang ditimbulkannya antara lain anorexia, lemas dan cenderung untuk duduk, kekurusan dan kelemahan, sesak nafas dan in- koordinasi dan terjungkal terlihat pada stadium akhir dan selanjutnya kalkun mengalami coma kemudian mati…dst
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