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All Journal Journal of Tropical Soils Jurnas Nasional Teknologi dan Sistem Informasi JURNAL NASIONAL TEKNIK ELEKTRO AGRITROPICA : Journal of Agricultural Sciences Jurnal Sains Agro Jurnal Rekayasa elektrika
Darmawan, Darmawan
Andalas University
Agriculture, Biological Sciences & Forestry Computer Science & IT Control & Systems Engineering Decision Sciences, Operations Research & Management Electrical & Electronics Engineering Energy Engineering Environmental Science

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Journal : Journal of Tropical Soils

 1 
Nitrogen and Phosphorous Movement Characteristic in Terrace Paddy Field Using Cascade Irrigation System in West Sumatra, Indonesia . Darmawan; Syafrimen Yasin; Tsugiyuki Masunaga
JOURNAL OF TROPICAL SOILS Vol 16, No 2: May 2011
Publisher : UNIVERSITY OF LAMPUNG

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.5400/jts.2011.v16i2.129-138

Abstract

West Sumatra is one of Indonesian rice bowl. The landscape of this province dominated by mountainous area with beautiful terrace paddy field lied from the middle slope to the lowland. The most common rice cultivation management in this area is application of cascade irrigation system with blanked amount of chemical fertilizer application. This study intends to figure out, whether this kind of paddy field management sustains and friendly to the environment or not. The results showed that cascade irrigation system created some discrepancies in suspended solid (SS), dissolve organic matter (DOM) and the nutrient movement characteristic a long the slope. The SS and DOM load and discharge strongly influenced by land preparation activities, while total and available nitrogen (N) and phosphorous (P) affected by chemical fertilizer application. In the upper part, the amount of chemical fertilizer seemed sufficient, indicated by negative amount of nutrient balance, while lower terrace show some indication of excess nutrient input. To avoid some demerit of cascade irrigation system, chemical fertilizer application should be base on site specific characteristic and taking into account of natural source contribution.Keywords: Cascade irrigation, chemical fertilizer, nutrient balance, terrace paddy field
Changes of Soil Properties on Various Ages of Rubber Trees in Dhamasraya, West Sumatra, Indonesia Syafrimen Yasin; . Adrinal; . Junaidi; Erick Wahyudi; Silvia Herlena; . Darmawan
JOURNAL OF TROPICAL SOILS Vol 15, No 3: September 2010
Publisher : UNIVERSITY OF LAMPUNG

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.5400/jts.2010.v15i3.221-227

Abstract

Changes of Soil Properties on Various Ages of Rubber Trees in Dhamasraya, West Sumatra, Indonesia (S Yasin, Adrinal, Junaidi, E Wahyudi, S Herlena and Darmawan): Although rubber has been planted in Indonesia from Holland era, but there is little information about the effect of rubber plantation on the rate of land degradation in Indonesia.  In order to examine the effect of rubber tree (Hevea brasiliansis) ages on land degradation status, a series experiment was done in Dhamasraya district as the main contributor of natural rubber in West Sumatra, Indonesia. Study site divide  into forest (A), crab grass (B), and rubber plantation with ages ranged from 1 (C), 5 (D), 10 (E), 15 (F) and 20 (G) years were selected as study sites and soil samples had been taken from each site, where forest soil  was used as a control. The result proved that the age of rubber tree has strongly affected physical and chemical properties of soil. Organic carbon and total nitrogen content decreased from 3.02%, 2.66%, 1.96%, in site A, B and C, and then increased to 2.33% and 2.49% in site D and E, respectively. This result was opposed with bulk density (BD) value of each site. The highest BD found in site C (1.26 g cm-3), followed by site D, E, B and A with 1.24, 1.14, 1.12 and 0.88 g cm-3, respectively. The similar pattern was also found for selected chemical properties of soil. Soil pH, available phosphorous, exchangeable base cations, cation exchange capacity and base saturation was likely to decrease from 1 to 10 years old plantation and then increased close the natural condition (reflected by forest soil) at 20 years old rubber tree. Since most of plantation was conversed from natural forest, this phenomenon might be because of contribution of organic matter from original condition and addition of fertilizer at the beginning of plantation establishment.
The Properties of Humic Acids Extracted from Four Sources of Organic Matters and Their Ability to Bind Fe2+ at New Established Rice Field . Herviyanti; Teguh Budi Prasetyo; Fachri Ahmad; . Darmawan
JOURNAL OF TROPICAL SOILS Vol 15, No 3: September 2010
Publisher : UNIVERSITY OF LAMPUNG

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.5400/jts.2010.v15i3.237-244

Abstract

The Properties of Humic Acids Extracted from Four Sources of Organic Matters and Their Ability to Bind Fe2+ at New Established Rice Field (Herviyanti, TB Prasetyo, F Ahmad and Darmawan):  In order to identify the properties of humic acid extracted from four kinds of organic matters (a peat soil, a stable manure, a compost of rice straw and a municipal waste)  and their potentiality to bind Fe2+  at new established rice field, a series of experiment was done in Soil Laboratory Faculty of Agriculture, Andalas University Padang. First step was characterization of functional groups and other chemical properties of humic acids, and their reaction with Fe2+. The second step was to examine the ability of humic acids to bind Fe2+ solution at new established rice field by conducting incubation experiments.  The experiment used  a completely randomized design with three replications.  The 450 ppm Fe solution was treated with 0, 50, 100, 150, 200, 250, 300, 350, 400, and 450 ppm humic acids and incubated for 24 hours.  While top soil samples taken from Sitiung, West Sumatera were treated with 0,100, 200, 300, and 400 ppm humic acids, flooded with deionized water, and incubated for 6 weeks.  The result showed that   the functional group and other chemical characteristic of humic acid from rice straw compost and peat soil were better than those of manure and municipal waste compost. Functional group of both humic acids was dominated by COO-. High reactivity of the humic acid had been found when humic acids were added to Fe solution with ratio 1 : 1. Use of humic acid extracted from peat soil with the levels from 0 to 100, 200, 300, and 400 ppm decreased the Fe2+ concentration from 1.361 ppm to  910, 860, 831, and 776 ppm, respectively at new established rice field.  While the use of humic acid extracted from  rice straw compost with the same levels as above decreased the Fe2+ concentration  from 1361 to 770, 701, 612, and 600 ppm, respectively, after four weeks of flooding.
Co-Authors . Adrinal . Junaidi Agustian Agustian Amirul Luthfi Baharuddin Abbas, Baharuddin Baharudin Baharudin Budi Sunaryo Eka Putra Waldi Erick Wahyudi Fachri Ahmad Hasnelly Hasnelly Herviyanti Herviyanti Ikhsanul Adli Lovely Son, Lovely Pharmayeni Pharmayeni Pharmayeni Pharmayeni Pharmayeni, Pharmayeni Sari Handani Silvia Herlena Sunaryo, Budi Syafrimen Yasin Teguh Budi Prasetyo Teguh Imanto Tsugiyuki Masunaga Yayan Syafriyatno