Judul: Combined use of inorganic and organic fertilizers for tomato yield and fertility of oxisols
Abstrak: Productivity of Oxisols could be improved by addition of organic and inorganic fertilizer. Recently, the use of organic fertilizer is increasing for long term friendly fertility management. The objectives of this research were to determine the appropriate combination of inorganic and organic fertilizer application on tomato yield and to increase nutrient utilization efficiency in the soil, and to determine the effect of combination of inorganic with organic fertilizers on soil chemical properties. The experiment was conducted at Bogor Agricultural University from November, 2009 to July, 2010. The treatments were designed using Factorial experiment in Randomized Complete Block Design (RCBD) with three replications. The treatment consisted of two factors which were rates of inorganic fertilizer [(0-0-0), (2.53 urea- 1.68 SP- 3 KCl), (4.68 urea- 3.12 SP- 6.52 KCl) and (7.2 urea- 4.8 SP- 10 KCl) (g/pot)], and organic fertilizer [0, 200, and 400 (g/pot), (Compost of cow dung, husk and straw in the ratio 1:1:2 by volume) or (Compost of cow dung, husk and peat in the ratio 1:1:2 by volume)]. Replication was treated as block. Data were analyzed using Microsoft Excel, ANOVA using the General Linear Model (GLM) option of Minitab software. The result of the research indicated that combined use of inorganic and organic fertilizers had positive effects on tomato yield and plant nutrient efficiency. The best combination of inorganic fertilizer occurred at lowest doses with organic fertilizer at 200 or 400 g/pot. Combination of inorganic fertilizer at (2.53 urea- 1.68 SP- 3 KCl, g/pot) with straw or peat compost at 400 g/pot resulted in the highest tomato yield than other combinations. Combination of inorganic fertilizer at (2.53 urea - 1.68 SP - 3 KCl, g/pot) with straw compost at 400 g/pot or peat compost at 200 and 400 g/pot resulted in the highest nutrient efficiency. Soil chemical characteristic after harvesting in both organic and inorganic fertilizer treatments had a sound of soil fertility than the soil before planting or fertilizing and increased the use of fertilizers also increased on the soil fertility.
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Judul: Development of soil test of phosphorus and potassium for fertilizer recommendation of tomato
Abstrak: The best management practices for fertilizer application on vegetable crop in Indonesia are not available at present. Environmentally friendliness in fertilizer recommendation based on soil analysis has been adopted by many developed countries for crop production. Soil testing using single-nutrient soil analysis in Indonesia has been developed since 1970. However, due to limited research fund, soil testing has not been programmed continuously and recommendation for fertilization of specific location based on soil family has not been established yet. Therefore, this research developed the basic model of P and K fertilizer efficiency and recommendation based on soil analysis for tomato in Inceptisols. This model will be adopted for other vegetable crops and different soil type in the future. Tomato is a vegetable growing well on Inceptisols soil type, which generally has low pH and high P-fixation. Research was done in greenhouse and open field of Cikabayan, UF, IPB, from March 2010 to December 2011. The objective of this research was to develop the best management practice for P fertilizer and K fertilizer recommendation based on soil analysis on Inceptisols for tomato. The study was designed in two years. The first year was to build recommendation for P and the second year for K fertilizer. Each study consisted of three experiments. First experiment was correlation study that aimed at finding out the best extraction method. The second experiment was calibration study that aimed at developing soil response category. The third experiment was recommendation study that aimed at building P and K fertilizer recommendation for each soil category on Inceptisols for tomato. Treatments were phosphorus and potassium rates i.e. 0X, ¼ X ½ X ¾ X and 1X, where X was 368.6 P2O5 kg ha-1 and was 608.6 K2O kg ha-1. Correlation of soil P and K test with tomato growth was conducted in the greenhouse through media obtained from soil incubation processes. Soil P test used five extraction methods i.e. Bray I, Bray II, Mehlich I, Morgan Wolf and Truog. Soil K test also used five extraction methods i.e. Mehlich I, Morgan Vanema, Truog, HCl 25% and NH4OAc 1 M pH 7. Calibration test was arranged in a completely randomized design with two factors. The treatment consisted of several soil P status (levels) ranging from very low to very high. Fertilizer dosage i.e. X, ¾ X, ½ X, ¼ X, and 0X was the second factor, where X was 368.6 P2O5 kg ha-1 for P and was 608.6 kg ha-1 K2O for K. Results showed that there were significant differences among P and K fertilizer treatments on plant height, stem diameter, leaf number, fresh biomass and dry biomass for both correlation test and calibration test. The correlation test showed that the best extraction reagent was Mehlich I for P and Truog for K. Fertilizer recommendation criteria for “very low-nutrient status” was 183.3 P2O5 kg ha-1 and 281.3 K2O kg ha-1. Fertilizer recommendation for “low-nutrient” status was 71.4 P2O5 kg ha-1 and 178.6 K2O kg ha-1.
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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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