nan Widiatmaka

Establishing Land Suitability Criteria for Cashew (Anacardium occidentale L.) in Indonesia

Commodity development requires site selection which should be established prior to large scale development. The land suitability criteria for cashew are not presently available. The relationship between the biophysical aspects, especially land and soil with commodity productivity, is also not known in depth. The objective of this study is to establish the criteria of land suitability for cashew in Indonesia, based on its production and land characteristics. Cashew plantations in 5 provinces were sampled. The data of production per tree per year were obtained from farmers, while the soil was sampled and analyzed in the laboratory. Age-adjusted cashew production was used as the yield response and plotted against land characteristics. Boundary lines resulting from the scatter of points were described; these lines produced the limits of land suitability criteria. The criteria were established using a projection of the intersection between the boundary line and yield interval. The criteria were also built in accordance with the productivity index of FAO for the internal boundary inside the S (suitable) class and by calculating the break-event point production for the boundary between S (suitable) and N (nonsuitable) order. The main result of this research is land suitability criteria for cashew.

Assessing the Suitability and Availability of Land for Agriculture in Tuban Regency, East Java, Indonesia

Indonesian food production depends highly on Java Island, which holds the most fertile soils in the country but had limited area. The objective of the research was to analyse the availability of suitable land for agriculture in Tuban Regency, an agricultural regency in Java Island. Land suitability was evaluated with spatial multicriteria analysis, integrating soil order, land capability, elevation, slope, slope direction, land use/land cover, accessibility, and climate. Land availability was analysed, integrating the forest area status designation and the spatial pattern of regional official land use plan. The results indicated that suitable land for agriculture corresponds to 91% of the total study area, confirming the high soil fertility. Analysis of land availability then indicated that 18% of the area was both suitable and available for agriculture. Considering the actual land utilization, the future development of agriculture in the region has less than 7% of the land area left for agricultural expansion. The overall results showed the importance of looking for land allocated for agriculture outside Java Island to anticipate the need for food of a country with a high population growth rate and also developing planning for food production.

Identification of flood area in the coastal region using remote sensing in Karawang Regency, West Java

Flooding often occurs in the lowlands, while the area is usually a rice production centres which affects the rice crop. Rice fields is generally located on fluvial plains and usually located in coastal areas, with relatively lower altitudes than roads or settlements. Physically wetland is an area flooding hazard and wetlands tend to longer floods than surrounding areas. Flood-hazard areas are formed due to sedimentation and usually at the confluence of river. This area is a fertile area for agriculture, has shallow ground water which is well suited for residential and urban areas. Karawang regency is one of the largest producers of rice commodities in West Java, therefore the Karawang regency government faces a challenge in maintaining the level of rice production due to global climate change that worsen the threat of flood hazard, in addition to land use change and increasing population. Based on the results of the spatial analysis from period of 2000 to 2006 the wetland area have been converted up to 7,493 ha. For the period of 2006 to 2015 wetland area have been converted up to 14,416 ha. Utilization of Geographic Information System with a model of Cellular Automata - Marcov Chain is an appropriate method for studying the phenomenon of expansion of build ups land in coastal region. The primary data used in the research is a land cover map of 2000, 2006 and 2015, which were the results of the multispectral classification of Landsat. The prediction of land cover change for the next fifteen years shows a continuous increase in built up area. The expansion of built up area and the possibility of widespread flood hazard areas, have inverse relationship with the decreasing of agricultural land area.

KARAKTERISTIK LAHAN PADA PERTANAMAN DUKU (Lansium Domesticum Corr) DI PROVINSI JAMBI

Duku is one of horticultural crops and tropical fruits that has high commercial value. Government of Jambi Province intends to maintain and develop duku through crop improvements and extensification. For that purpose it needs to understand crop requirement related to land characteristic. The aims of this research were to identify land characteristics that associated to duku productivity, describe the optimum land characteristics to support maximum duku productivity, and to investigate the significance influence of land characteristics on optimum duku productivity. The study used primary and secondary data. Primary data was collected through field surveys, including biophysical properties and crop productivity. Secondary data included climate and duku distribution in Jambi Province. Data analysis were used line boundary method analysis and discriminant analysis. Biophysical properties and productivity were plotted on scatter diagram and the distribution of points form a model of the boundary line. The model of the biophysical properties and production relationship could determine land characteristics that associated with optimum productivity. The optimum productivity was associated with soil texture of sandy clay, sandy clay loam, loam, and clay loam, soil depth > 56 cm, soil pH between 4.5 to 6.4, C organic content > 0.60%, CEC was > 16.0 cmol kg-1, base saturation was > 5%, available P was > 1.50 ppm, exchangeable K content > 0.50 cmol kg-1, and Al saturation was < 43%. The discriminant analysis showed that the soil pH had the highest contribution on duku productivity. Key word: Boundary line, Duku, land characteristic, productivity