Plot Scale Phosphorous and Potassium Balances of Newly Opened Wetland Rice Farming Originated From Wetland

Development of newly opened wetland rice fields both from dry land and wetland in Indonesia are important to meetrice growing demand, increase soil productivity, keep rural food security and provide jobs as well as generateincome. Most soils of newly opened rice fields are low in P and K contents, but the farmers do not apply P and Krecommended fertilisers. The study was conducted on newly opened wetland rice farming in Panca Agung village,Bulungan District, East Kalimantan Province, Indonesia in 2009. The aims were to evaluate phosphorous andpotassium input – out of newly opened wetland rice and to validate the P and K recommendation. Six treatmentswere tested including farmers practices (as control), farmer practices + straw compost + dolomite, NPK withrecommendation rate in which N and K was split in two applications, NPK with recommendation rate in which N andK was split three applications, NPK with recommendation rate + straw compost + Dolomite , in which N and K wassplit three applications, and NPK with recommendation rate + straw compost + dolomite, in which N and K weresplit two applications. The N, P and K rates were 250 kg urea, 100 kg SP-36 and 100 kg KCl ha-1 season-1, while thefarmer practices 100 kg urea and 100 kg SP-36 ha-1 season-1. Parameters to be measured were concentration P andK in mineral fertilizer, compost, irrigation water and grains as well as straw. The results showed that surplus Pranged from 5.75 to 12.85 kg P ha-1 season-1, meaning that SP-36 application rate was more than enough to replace Premoved by harvest product. In contrast, potassium application rate should be increased from 100 to 200 kg KClha-1 season-1 to fix K removed by harvest product. However, when the compost will also be increased to 3 Mg ha-1season-1 K fertilizer can be increased to 150 kg KCl ha-1 season-1 to substitute K taken away by rice harvest productand to keep higher rice grain yield. These P and K recommendation rate imply that total SP-36 and KCl should beavailable at district level will be about 984.9 Mg SP-36 and 1.477 Mg KCl district -1 season -1, respectively.Keywords: Newly opened wetland rice; nutrient balance; nutrient input; nutrient losses; plot scale wetland[How to Cite: Sukristiyonubowo, K Nugroho and S Ritung. 2012. Plot Scale Phosphorous and Potassium Balances of Newly Opened Wetland Rice Farming Originated from Wetland. J Trop Soils 17 (3): 227-237. doi: 10.5400/jts.2012.17.3.227][Permalink/DOI: www.dx.doi.org/10.5400/jts.2012.17.3.227]&nbsp

Perkembangan Dan Permasalahan Sistem Klasifikasi Tanah Di Indonesia

. Soil research in Indonesia began in 1817 but officially soils classification research began in 1905. The first soil classification of soils in Indonesia was prepared by E. C. J. Mohr in 1910 at Bodemkundig Instituut. Soils classification is based on the principle of genesis and soils classified are named on the basis of color. This classification was updated several times in 1910, 1916, 1922, and 1933. In 1972 Mohr with van Baren and Schuylenborgh published a book on soils in the tropics with the title "Tropical Soil, A comprehensive study of their genesis". Further soil classification is White classification which was developed in 1931. In the White classification system, the nature of the soil classification is based on geology and type of weathering, but the names of the soil is still too long and complicated. In 1938 in Deli soil classification was prepared by Druif for soil mapping in the area of tobacco plantation. Druif research results have been reported in detail in 3 series of book De Bodem van Deli. Soil classification system considered advanced, based on morphometric, is a classification system of Dudal and Soepraptohardjo (1957, 1961). This classification system is used in the soil mapping resources in Indonesia at the level of semi detail and exploration. In 1983, the Centre for Soil Research has published a soil classification system intended for semi-detailed soil mapping for transmigration program. The classification is based on the morphogenetic and a refinement of the classification system of Dudal and Soepraptohardjo (1961). Various definitions various especially at great group level is mostly using the definition of the Legend of the Soil Map of the World ( FAO / UNESCO, 1974) and adapted to the soil classification in Indonesia. Other soil classification system used in Indonesia is the soil taxonomy classification system which was began to be published in 1975. This soil classification system is still used to refer to the book of Keys to Soils Taxonomy, eleventh edition (2010). Other soil classification system is a World Soil Map Unit of the FAO/UNESCO (1974). Up till 2013, Indonesia does not have a national soil classification system, although several times of the National Congress of Soil Science Society of Indonesia has mandated to formulate a national soil classification. The efforts made by the Indonesia Center for Agricultural Land Resources Research and Development is successful to draft national soil classification which was introduced in 2013, but this concept still requires improvement and recognition from experts soil genesis and classification throughout Indonesia

Detecting Tidal Flood Pattern with Landsat TM Remote Sensing Data in South Sumatra Coastal Area

Detecting the availability of sufficient water in tidal land management is important for agriculture. Tidal flood pattern provides an information of area where has tidal flood as well as drought by time and places. The objectives of this research are 1) to study the tidal flood spatial pattern by using real time data and digital data image processing, 2) to determine a tidal flood classification based on ground water level on a specific locationand time, and 3) to study the hydrological factors affecting the flood. The tidal flood pattern can be classified within a block by their ground water fluctuation. The visual analysis with four image of different time, gives a clear differences between tidal flood pattern change and tidal fluctuation. The classification on the moist Landsat TM image after a Tesseled Cap transformation can produce classified image with similar flooded condition with the same range of ground water level. After the test, the tidalflooded pattern was found similar with the classification results. The tidal flood pattern is also recognized having a specific relationship with land use or land utilization type. The land use and land management affect the pattern. The application of geographical information system, especially remote sensing digital image data analysis, will help in determining tidal flood pattern as well as the ground water spatial pattern