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Sulaeman Y.,Indonesian Center for Agricultural Land Resource Research and Development | Minasny B.,University of Sydney | McBratney A.B.,University of Sydney | Sarwani M.,Indonesian Center for Agricultural Land Resource Research and Development | Sutandi A.,Bogor Agricultural University
Geoderma | Year: 2013

Soil legacy data are basic input data for digital soil mapping. Any monitoring of global soil change cannot be successful unless soil data availability and characterization at the national level are well understood. Spatial data infrastructure frequently hampers many developing countries to take advantage of their soil legacy data for digital soil mapping at the national and regional level. While the initial purpose for developing a soil database is to store survey data, it cannot be efficiently used to support quantitative, digital soil mapping and assessment. This paper aims to develop a prototype soil observation database for global soil mapping in Indonesia. We will outline the steps needed to prepare legacy data for digital soil mapping, and describe the challenges and the Indonesian responses. The steps cover (i) legacy data identification and collection, (ii) data selection, (iii) database development and population, (iv) data harmonization and display, and (v) dataset integration. Because of uncoordinated and poorly-defined soil databases, we have to resort to a pragmatic approach to build a new and simpler database to support mapping activities. Historical soil survey reports and soil maps were collected, scanned, and summarized. After various considerations, we decided to only use soil profile observations which have clear geographical coordinates. We designed a database for soil profile observations and implemented it at two levels: spatial site data and horizon data. Spatial site data includes site geographical coordinates and attributes, while horizon data includes soil physical and chemical properties. The depths of soil profile database entries were standardized using the equal-area spline. Soil legacy data management for supporting digital soil mapping and GlobalSoilMap.net project are then discussed. These steps and data management are found helpful in Indonesia and this experience may be useful for other countries having similar impediment. © 2012 Published by Elsevier B.V. Source

Anda M.,Indonesian Center for Agricultural Land Resource Research and Development | Sarwani M.,Indonesian Center for Agricultural Land Resource Research and Development
Soil Science Society of America Journal | Year: 2012

Unusually huge amounts of fresh ashfall from the eruption of the Merapi volcano (occurring October-November 2010) resulted in severe deposition problems (1-29-cm thickness) on many agricultural lands. The objectives of the study were (i) to determine the mineralogy and elemental compositions of the fresh ash, (ii) to assess solvent-extracted cations and the composition of pristine ash leachates in water, and (iii) to anticipate the possibility of using fresh ash as a new source of nutrients. Mineralogical composition was determined by a polarization microscope and total elemental composition by x-ray fl uorescence. Dissolved elements were measured from the solid phase (extracted by NH 4AOc) and water from river stream fl ow and canals. Results showed that the mineralogical composition was relatively uniform and dominated by volcanic glass (49% on average) followed by labradorite (26%) and augite (13%), with trace amounts of bytownite, hypersthene, hornblende, and opaque. This indicates that the fresh ash contains mainly easily weatherable minerals. Total element contents consisted of macronutrients in the order of Ca Na > K > Mg > P > S and micronutrients of Zn, Fe, Mn, Cu, and Co. Findings from study of pristine ash leachates from river and canal waters, representing natural conditions, clearly demonstrated the high concentrations of base cations (Ca Na Mg > K) and anions (SO4 Cl > NO 3 PO 4). Base cations extracted by NH 4OAc were in the order Ca Mg > Na > K and the base saturation was >100% (114-484%), confi rming that cations in rivers and canals are from soluble salts. The high amounts of ions released from fresh volcanic ash indicated its potential as a source of nutrients. © Soil Science Society of America. Source

Anda M.,Indonesian Center for Agricultural Land Resource Research and Development | Kurnia U.,Indonesian Center for Agricultural Land Resource Research and Development
Communications in Soil Science and Plant Analysis | Year: 2010

Upland agriculture in Indonesia mainly relies on Ultisols and Oxisols, which have serious problems resulting from severe erosion and low organic-matter content. The objectives of the study were (i) to assess the effect of long-term rehabilitation techniques on soil organic carbon (SOC) and maize yields of a desurfaced Ultisol and (ii) to assess the effect of short-term rehabilitation techniques on desurfaced Oxisol properties and soybean yields. A 7-year field experiment was conducted on artificially desurfaced Ultisol grown with maize (Zea mays L.). The results showed that rehabilitation techniques using cattle manure, rice straw mulch or Mucuna sp. mulch were successful in restoring SOC content of degraded Ultisol to its initial natural state. All sources of organic-matter rehabilitations significantly increased maize yields on an Ultisol. Rehabilitations of degraded Oxisol under glasshouse conditions using phosphorus (P) fertilizer, organic matter, basic slag, and lime could increase cation exchange capacity (CEC) and nutrient availability and suppress Al toxicity. At the same time, soybean yields increased 11-14, 2-10, 1-5, and 1-3 times, respectively. © Taylor & Francis Group, LLC. Source

Sulaeman Y.,Indonesian Center for Agricultural Land Resource Research and Development | Sarwani M.,Indonesian Center for Agricultural Land Resource Research and Development | Minasny B.,University of Sydney | McBratney A.B.,University of Sydney | And 2 more authors.
Digital Soil Assessments and Beyond - Proceedings of the Fifth Global Workshop on Digital Soil Mapping | Year: 2012

Information on the spatial variability of soil pH across the landscape is required for many ecological and environmental models. In Indonesia, particularly in Java, such information is the basic input to understand the decline of land productivity due to imbalanced fertilizer application. Creating soil maps using digital techniques has a great potential for efficient soil property mapping. Within the monsoon climate in the tropical region, the factors that control soil pH variation are important to comprehend. This study aims to investigate factors controlling soil pH variation in Java, and to build soillandscape models for mapping soil pH at a regional scale. 275 soil profiles were compiled from previous soil survey activities conducted since 1987. The soil pH values were derived from soil profile observations and grouped into 0-30 cm, 30-50 cm, and 50-100 cm depth ranges. Environmental covariates were derived from shuttle-radar DEM, an agroclimatic map, and a geology map. From this dataset, 207 profiles were used to develop prediction models using a recursive partition (decision tree) algorithm and stepwise regression. Results showed that there is a specific combination of covariates and techniques of parameterization that gives the best prediction of pH variation at a given depth. The most important covariates for predicting pH at 0-30 cm are multiresolution index of ridge top flatness (MrRTF) and land age; for depth of 30-50 cm: MrRTF and parent material; and for 50-100 cm: elevation and parent material. We tested the regional model to map soil pH variation in the Subang region of West Java. The digital soil mapping technique was found useful in providing soil pH map to support national programs in food security efficiently. © 2012 Taylor & Francis Group. Source

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