Jurnal Tanah dan Air (soil and water journal)
Volume 2 No. 1, Juni 2001
Penelitian Pendahuluan Mengenai Status Hara Fosfor (P) pada Tanah Pertanian di Propinsi Maluku (Andriko Noto Susanto, R. Agus Widodo) Abstract: Prelimenary study on P distribution in Mollucas Province have been carried out in June 1998 through July 1999. Single and comosite soil were collected from 15 area of island groups I, III, V, VI and VIII. P status was determined by extraction in HCl 25% method. Concentration of<20mg P2O5/100gr soil was considered low status, while those with ranges of 20-40 mg P2O5/100 gr soil and >40 mg P2O5/100 gr soil were moderate and high status, respectively. Results showed that of 42 samples analyzed, 19 samples were considered having low P status (1.53-19.54 mg P2O5/100 gr soil) 12 samples having moderate P status (28.20-35.60 mg P2O5/100 gr soil) and 11 samples was high (42.20-674.82 mg P2O5/100 gr soil).
Peranan Asam-Asam Organik Berberat Molekul Rendah terhadap Ketersediaan Fosfat Andisol (Lelanti Peniwiratri, Dja'far Shiddieq, Abdul Syukur) Abstract: Research was conducted to establish the rele of low-molecular-weight organic acids with different rates on the availability of P by depressing the P adsorption of Andisol. Factorial design in Completely Randomized Design with 2 factors was used. First factor is organic acid rate with 3 levels: lactic acid (A1); malic acid (A2) and citric acid (A3). The second factor is organic acid with 4 levels: 0 (K0); 7,5 (K1); 15,0 (K2) and 22,5 mmol/kg of soil (K3). The relust showed that the effective rate of lactic and malic acid (22,5 mmol/kg of soil) and citric acid (15,0 mmol/kg of soil) decreased the P-adsorption and increased available-P of Andisol. The effective of organic acid in the order citric acid > malic acid > lactic acid.
Pengaruh Kapur Dosis Rendah dalam Budidaya Padi Tabela pada Tanah Sulfat Masam Potensi (Masganti) Abstract: Decreasing of fertile agriculture land in Java by using for housing and other nonagricultural purpose causing function of Java as a national rice-barn must be changed to marginal lands out of Java. Tidal swamp area os very important to be developed as a new national rice-barn in order to increase rice production in Indonesia. Potential acid sulphate soil os one of soil type in tidal swamp area. Using this land for rice production facing some problem such as low pH and low calcium soil content. The objective of this research was to find out the optimum level of lime on direct seeded rice in swamp area. The research was conducted on potential acid sulphate soil of Karang Buah Village of Barito Kuala District, South Kalimantan from September 1999 untul January 2000. The level of lime were: 0, 125, 250, 375, 500, 625, 750, 875, and 1,000 grains yield. The result showed influenced by lime. The estimated highest grain yield of direct seeded rice (3,18 t/ha) was supported by application of 450 kg CaCO/ha.
Pembuatan Bahan Pembenah Tanah (Soil Regenator) dan Pengujiannya terhadap Pertumbuhan Jagung pada Ultisol dan Entisol (Azwar Maas, Sri Hartadi, Sri Nuryani Hidayah Utami) Abstract: Fresh to well decomposed organic materials either or not enriched with nutrients and are inoculated with micro organisms, in general have been used as soil regenerator or for soil amendment. Up to the present, these natural organic materials are imported and sold in dry packed form (i.e. OST). The materials consists of high potential nutrients from plant or animals origin, and were inoculated with micro organisms. Application to the soil with enough water, these micro organisms will become active in degrading the raw materials of carrier.
In Indonesia, peat land covers more than 20 million hectares, this peat potentially can be used as a carrier or raw materials of soil regenerator. The original and improved peats, as a carrier, have been inoculated with Pseudomonas and Bacillus for phosphate solubilizing bacteria, Azotobacter for non-symbiotic nitrogen fixation. Tricoderma also has been used for speeding up the peat, this fungus was inoculated in a fine enriched rice hull. These materials (three peat quality), waste city compost, and an imported soil regenerator (OST), as soil generators, have been tested in Entisol (Regosol) and Ultisol soils at the level of 10 ton ha-1, corn was used as plant indicators.
The result showed that the given organic matter were abel to improve the growth and the biomass production of the corn. The residual effect resulted in richer nutrients and organic matter in the soil after the corn has been harvested. The waste city compost has similar effect as the peat compost on the plant growth and soil fertility; while the OST has no different effect to the control. The origin peat conatains more nitrogen and ther nutrients than the enriched peat, but still contains acidity. This origin peat showed markedly increases the corn growths and biomass productions in both soils, but its residual organic matter in the soil still in a quite high value of C/N ratio.
In relation to the microbial activity, the inoculated soils showed that there was no nitrogen or sulphur deficiency, as shown in the uninoculated soil. These figures showed that the microbial nitrogen fixation or supply of nitrogen and/sulphur from raw materials occurred in the inoculation treated soils.
Mineralogi Vertisol dari Bahan Induk Tuf, Napal dan Batupasir (Djoko Mulyanto, Mohammad Nurcholis, Triyanto) Abstract: Three profiles of Vertisol which developed from volcanic tuff, and sandstone, respectively were studied. The first two soils were from Ngawi and the last from Bojonegoro. Mineral composition of rocks was analyzed using thin section and also using x-ray diffraction on powder material. Clay mineralogical composition was determined using x-ray diffraction and sand mineralocigal was determined by line counting method using polarization microscope. The result showed that plagioclase and glass on tuff and plagioclase on sandstone were very dominant in the formation of secondary minerals, especially smectite and few haloysite, while promary minerals which dominant in the formation of smectite in Vertisol developed from marl were olivine and pyroxen. It was predicted that smectite developed from marl also developed from other sources of volcanic materials. Analysis by x-ray diffraction and thin section on parent materials predicted that the clay minerals besides by pedogenic process were also inherited from those parent materials.
Peranan Data Mineral Tanah dalam Menunjang Interpretasi Sumber Daya Tanah (Chendy Tafakresnanto, Bambang Hendro Prasetyo) Abstract: Minerals are the main compiler of soil, and their existence would influence physical and chemical properties of the soils. Minerals such as plagioclase, hornblende, augite, hypersthenes which are dominant in the soils indicate that nutrients source of the soil is high. In other hand soils which are dominated by quartz and opaque indicate that the soil is oor of nutrients. Difference in mineral composition between two kinds of soils indicates that their soil parent materials are different. Soil which is dominated by smectite clay mineral has high negative charge, while soil which is dominated by kalinite has low negative charge. Amorphous alofan, imogolite and iron or aluminum oxide often caused high pretention in the soils.
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