Supiandi Sabiham

Estimation of the Potential Carbon Emission from Acrotelmic and Catotelmic Peats

This research was completed using mixed qualitative and quantitative methods. Field surveys were executed in sugar cane plantation throughout South Sulawesi Indonesia. Land suitability analyses were performed using a parametric approach with Storie’s index equation followed up with correlation analysis using the Pearson correlation. Results revealed that the period for sugarcane crop growth in the humid tropic relatively dry regions of South Sulawesi Indonesia lasted for the months of November to July. The land suitability for sugar cane in the research location was moderately suitable (S2c) and marginally suitable (S3c, S3s, S3s,f and S3c,w) with limiting factors such as relative humidity during crop maturation phase, the duration of sunlight, soil depth, soil texture, soil pH and soil drainage. Land suitability index at the research location ranged from 25.2 to 55.0; sugar cane yields ranged from 30.3 to 62.0 Mg ha year. Pearson correlation coefficient (r) between LSI with cane and sugar productivity were 0.81 and 0.84 respectively, signifying the strength of the correlation between the two values. This also indicates that land suitability index can be estimating the potential crop yield in the humid tropicsthat relatively dry climate regions.Field experiment with a split plot design has been carried out in order to assess the growth characteristics and yields, and effectiveness of MVA upland rice which were given potassium fertilizer in two growing seasons. MVA inoculation consisted of three treatments (without MVA, Glomus sp. and Gigaspora sp.) while potassium fertilizer consisted of five levels (0, 12.5, 25, 37.5, and 50 kg ha-1 K). The results showed that plant growth variable which was inoculated by MVA at any levels of K fertilizer was higher in the dry season than that in the wet season, whereas the opposite occurred for net assimilation rate. Potassium content of leaf tissue, shoot/root ratio, and grain weight per hill was determined and mutually dependent on genus MVA, dosages of K fertilizer, and growing season. Harvest index and grain dry weight per hill were influenced by the growing season and the genus MVA but the effect did not depend on each other. At all dosages of K fertilizer and any MVA genera, Gigaspora sp. inoculation was better than that of Glomus sp. Dry weight of grains per hill was affected by the contribution of grain content per hill, weight of 1000 grains and number of productive seedlings per hill. The optimum dosage of K fertilizer in the dry season was 32.4 kg ha-1 K with grain yield 3.12 Mg ha-1 for inoculation of Gigaspora sp., whereas the optimum dosage in the wet season was 34.2 kg ha-1 K for the treatment Glomus sp. inoculation with Gigaspora sp. in the wet season did not reach dosages of optimum K fertilizer. Keywords: Harvest index, MVA, potassium fertilizer, upland rice [ How to Cite : Natawijaya D. 2012. Increasing Growth and Yield of Upland Rice by Application of Vesicular Arbuscular Mycorrhizae and Potassium Fertilizer. J Trop Soils 17 (1): 53-60. doi: 10.5400/jts.2012.17.1.53] [ Permalink/DOI: www.dx.doi.org/10.5400/jts.2012.17.1.53 ]This study aimed to examine Organonitrofos Plus fertilizer (OP) on sweet corn (Zea mays Saccharata L.) and its effect on changes in soil chemical properties of Ultisols. Organonitrofos Plus fertilizer is an enhancement of Organonitrofos fertilizer enriched with microbes at the beginning of the manufacturing process. Research was conducted in the greenhouse of Integrated Agricultural Laboratory of Lampung University. Treatment applied was a factorial of 4 t 2 t 3 with three replications in a randomized block design. The first factor was the dose of OP fertilizer (0, 10, 20, 30 Mg ha-1), the second factor was the dose of inorganic fertilizers (without inorganic fertilizers, and with inorganic fertilizers, namely Urea 0.44, 0.28 SP-36 and KCl 0.16 Mg ha-1), and the third factor was the dose of biochar (0, 10, 20 Mg ha-1). By a single OP fertilizers, inorganic fertilizers, and the interaction between the OP and the inorganic fertilizers increased the weight of dry stover, cob length, cob diameter, cob with husk and cob without husk of corn. OP fertilizers which are applied in Ultisols can improve soil fertility and increase corn production so that OP fertilizer can lessen the use of inorganic fertilizer and can be used as a substitute for inorganic fertilizer. RAE values were highest in treatment of O4K2B2 (30 Mg OP ha-1, with inorganic fertilizer, 10 Mg biochar ha-1) that was equal to 181%, followed by O2K2B3 (10 Mg OP ha-1, with inorganic fertilizer, 20 Mg biochar ha-1 ) with the difference in RAE value of 0.5%.[How to Cite: Dermiyati, SDn Utomo,n KF Hidayat, J Lumbanraja, S Triyono, H Ismono, NEn Ratna, NT Putri dan R Taisa. 2016. Pengujian Pupuk Organonitrofos Plus pada Jagung Manis (Zea mays Saccharata. L) dan Perubahan Sifat Kimia Tanah Ultisols. J Trop Soils 21: 9-17 Doi: 10. 10.5400/jts.2016.21.1.9][Permalink/DOI: www.dx.doi.org/10. 10.5400/jts.2016.21.1.9]Coco rind is a waste that if not used can cause environmental problem around the plantation. One way to utilize cocoa rind is by making it into compost which can be used as organic fertilizer. Different planting distance will affect on the number of plant population per unit area and will indirectly affect the absorption of nutrients, water and other growth factors. The purpose of this study was to determine the effect of the utilization of compost from cacao rind waste on the growth of Saccarum edule Hasskarl plant with different planting distance. The design used was to factor randomized block design with 2 replications, then there are 18 treatment combinations. In this research, the first factor of cacao rind composts comparison with cow manure consisted of three levels, they are: P1 = 50 kg; 10 kg; P2 =50 kg: 30 kg; P3 = 50 kg: 50. While the second factor uses the planting distance which consisted of three levels, they are: J1= 100 cm X 150 cm; J2= 100 cm X 100 cm; J3= 100 cm X 50 cm. Based on the research results, it shows that the best treatment of cocoa rind compost and cow manure, which affects on the number of buds is treatment P3 on 5 WAP, while the best used for the plants’ height is P2 on 3 WAP, and the best used for the leaves’ length is treatment P2 on 2 to 4 WAP.

The effect of volcanism on submontane rainforest vegetation composition: Paleoecological evidence from Danau Njalau, Sumatra (Indonesia)

Volcanic processes might have played an important role in the vegetation history of Sumatra, one of the largest and most tectonically active region in Southeast Asia. Palynological and macro-charcoal analysis results from Lake Njalau in the Kerinci Seblat National Park (KSNP) in Sumatra (Indonesia) provide an understanding of interactions between the volcanic deposition and vegetation in the past 5000 years. The deposition of volcanic material in the depression of the Lake Njalau (5100–4400 cal. yr BP) led to the dominance of pioneer species of Casuarina and Myrica, which grow in deforested land and volcano slopes (volcanophile taxa). The formation of the modern forest composition took several centuries after the volcanic deposition in the soil ended (ca. 900 years at ca. 2400 cal. yr BP). This suggests that the vegetation changes were not driven by a successional pattern, and soil formation was the most important environmental factor explaining this slow change in composition. The palynological records show no evidence for prehistoric human–landscape interactions in the area despite the close proximity to known megalith sites. The local fire regime reconstructed using macro-charcoal analysis indicates that fire was rare for the last 5000 years, and the average fire return interval was ca. 500 years. Phases of increased fire frequency could not be linked to either any of the vegetation phases or regional climatic changes, suggesting that fire occurrences were stochastic events. Our results overall suggest that volcanism has acted as one important driver of changes in the rainforests of the KSNP.

Effects of seasonal rainfall and water table movement on the soil solution composition of tropical peatland

ABSTRACT Understanding the composition of the soil solution of tropical peatlands is important because it directly affects nutrient availability and environmental degradation. The objectives of this study were to investigate temporal fluctuations in the soil solution composition in tropical peatlands in West Kalimantan and Riau, Indonesia and identify the factors controlling these fluctuations. In each site, we established four study plots consisting of three plots under oil palm (Elaeis guineensis Jacq.) plantation and one plot under uncultivated land as the control. Triplicate soil solution samples were collected at 50 and 200 cm depths, fortnightly. During the drought, the pH at 50 cm was low (3.7–4.0), which was influenced by oxidation reactions such as organic acids and NO3− generations. The pH at a depth of 200 cm was high (5.9–6.8), due to reduction reactions such as denitrification. High cation concentrations at both depths would result from organic matter decomposition and the limited downward movement of water. Rewetting the West Kalimantan peatland caused a sharp decrease in pH and ionic concentrations at 50 and 200 cm depths, because of the transportation of ions from the upper acidified layer. However, the lower rainfall levels in Riau than West Kalimantan resulted in a gradual decrease in pH and Ca2+ concentration. The higher pH levels and ion concentrations in West Kalimantan than in Riau would be influenced by the enhanced microbial activity due to water supply from the risen water table in this site. This study showed that seasonal rainfall and water table movement were the main factors controlling the fluctuations in the chemical composition of soil solutions.

Impacts of Oil Palm Plantations on Climate Change: A Review of Peat Swamp Forests' Conversion in Indonesia

Indonesia possesses a rich biodiversity with abundant natural resources such as tropical rain and peat swamp forests, oil and gas deposits, and fertile soils just to name a few. The state policies on natural resource management were decentralized and the power and local autonomy rights were given to provincial and district governments. This resulted in an enormous expansion of oil palm plantations across the country especially over the last three decades. On the one hand it boosted the countrys economy by bringing foreign money reserves, but on the other hand has led to severe deforestation, shifting cultivation, peat swamp forests conversion and land degradation. Thus, due to the severity of these environmental consequences and associated climate change implications, oil palm development has received significant attention from all stakeholders and is the subject of global debate. This paper aims to discuss the results of various studies regarding emissions of GHGs from oil palm plantations in Indonesia and highlights the fundamental methodologies

Historical Assessment of Forestland Conversion to Oil Palm Plantations in Riau and West Kalimantan, Indonesia

Forest’s conversion associated with the expansion of industrial scale oil palm plantations in the two provinces of Indonesia (Riau and West Kalimantan) was documented using Landsat images that were visually interpreted to create a province-wide map of 11 different land cover types spanning three temporal periods (1990 to 2000, 2000 to 2010 and 2010 to 2013). After analyzing all regions and temporal periods in both provinces only 1.66% (30,452 ha) of oil palm plantations originated on land derived directly from undisturbed forests (0.01% Primary Dryland Forest, 0.00% Primary Mangrove Forest and 1.65% Primary Swamp Forest), while 64.78% (1.18 Mha) were established on land previously covered with disturbed forest (12.14% Secondary Dryland Forest, 0.67% Secondary Mangrove forest and 51.97% Secondary Swamp Forest). Conversion of Dry and Wet Scrublands was documented as 23.82% (0.43 Mha) with 7.43% from Dry Scrubland and 16.39% from Wet Scrubland. Forest conversion to establish oil palm, including both undisturbed and disturbed forest of all types of habitats summed over all temporal periods was proportionally greater Original Research Article Rehman et al.; IJPSS, 6(1): 34-49, 2015; Article no. IJPSS.2015.095 35 in Riau (70.03%: 0.84 Mha), compare to West Kalimantan (59.52%: 0.37 Mha). In both provinces, the largest sources of land for new plantations were Secondary Swamp Forest (43.43%: 0.27 Mha) in West Kalimantan, while (56.40%; 0.68 Mha) in Riau.