Judul: Efisiensi penggunaan air tanaman padi dengan irigasi kontinyu dan berselang di Kecamatan Mijen, Semarang
Abstrak: Climate anomalies and climate change are obstacles in achieving a sustainable rice production. The use of appropriate and locally accepted technology and affective water use are needed at farmers level. This study was conducted to analyze water use efficiency of several varieties of rice namely Inpari 1, Umbul, Situ Bagendit, and Galur Harapan at two different spacing system (Jajar legowo and Tegel) with continuous and intermittent irrigation system. Water use efficiency (WUE) of plants were calculated by dividing dry biomass production with water used (ETc) during grow period. Water use was using reference evapotranspiration (ET0) corrected by plant coefficient (Kc). ET0 was calculated using FAO Penman-Monteith method. The result showed that WUE of plants grown with intermittent irrigation was higher than plants grown with continuous irrigation, both by production and total (9.93% and 10% respectively). Water use efficiency can be done with increased potensial crop yields or to reduce water of irrigation without reducing yields.
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Judul: Studi Konsumsi Air, Respon Pertumbuhan dan Produksi Dua Varietas Padi pada Beberapa Sistem Pengairan
Abstrak: Water is one of the important inputs to support the growth and development of plants. Currently, water availability tend to be more limited due to environmental quality degradation and global warming. This study was conducted to determine the amount of water consumption of two rice varieties (IR-64 and Jatiluhur) in four irrigation systems (conventional, water-saturated, intermittent, and upland). The study was performed using a split block design with three replications. Upland system planted with direct seeding, while for others system transplanted at 12 days old seedling. Rice plants were grown under plastic house with 3 m x 3 m area per experimental unit, and water volume recorded by flowmeter in inlet systems. Observed variable consist of growth component, stomatal charactheristics, productivity and production component. The results showed that the conventional system consumed the highest volume of water (426,768 l) in one seasson. The least consumption of water reached by upland system (3,883 l), while the water saturated system consumed 74.3% and intermittent consumed 37.9% of conventional system water consumption. In the other hand, the intermittent and conventional systems had higher productivity than water saturated and upland sytems. There were no significantly different between varieties in water consumption. However, the yields of Jatiluhur variety produced higher grain per plot than IR-64 variety. The highest efficiency of water consumption reached by upland system (0.531 g/l), the second was intermittent system (0.020 g/l), and the lowest were conventional and water saturated systems (0.008 g/l).
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Judul: Characterizations of low alloy steel sae 4422  plated with chromic acid (Cro3)
Abstrak: Characterizations of low alloy steel SAE 4422 plated with chromic acid (CrOrO3) was use Optical Microscopy (OM), Scanning Electron Microscopy (SEM), X-Ray Diffraction (XRD), RD),Energy Dispersive Analysis of X-Ray (EDAX), Hardness Test and Roughness Test. Microstructures analysis exhibits cracks and grain boundaries microcracks as a characteristics of chrome metal found at plating metal. Perlite and Ferrite as grains of steel found at base metal with grain boundaries around it. Phase analysis of plating metal appropriate to chrome metal with lattice constant (a) is 2.559 Å and phase analysis of base metal appropriate to iron ferrite with lattice constant (a) is 3.318 Å. Both plating and base metal have cubic system. Chemical analysis of plating metal at surface section exhibits that cracks area have highest value of carbon element compare with grains and grains boundaries area. While chemical analysis of base metal at cross section exhibits that perlite have highest value of carbon element compare with ferrite and grain boundaries. The hardness value of plating metal at surface section and cross section are 753 and 637 VHN. While, the hardness value of base metal and interface area at cross section are 205 and 373 VHN. The roughness value at measurement points of chrome surface for as received sample are 0.445 μm. Observation used Optical Microscopy and Scanning Electron Microscopy exhibits surface irregularities combine to form surface texture of plating metal at surface section.
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