The Importance of Peatland

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II. LITERATURE REVIEW

2.1 The Importance of Peatland

Peat deposits are formed from the remains of plants that have died, either has been weathered or not. Pile continues to grow because the process decomposition inhibited by anaerobic conditions or other environmental conditions. The low level of development of decomposing biota. Peat soil formation is a process of soil formation that geogenic caused by the deposition process and transport, in contrast to the process formation of mineral soil which is generally a pedogenic process Hardjowigeno, 1986 in Subiksa, 2008. In general, the classification of soil, peat soils are known as Organosol or Histosols are soils having a layer of organic material with density BD in humid conditions 0.1 g cm-3 with a thickness 60 cm or organic layer with BD 0.1 g cm-3 with a thickness 40 cm Subiksa, 2008. Peat is classified according to various different points of view; level of maturity, depth, fertility and the position formation. Based on the maturity level grade is divided into: • Peat Sapric mature peat is decaying peat that has been further decay and native materials are not recognizable, coloured dark brown to black, and when crushed, the fiber content reached 15 . • Peat hemic half mature peat is a peat half rotted, some original material is still recognizable, coloured brown, and when crushed fiber materials reached 15 – 75 . • Fibric Peat raw peat is the peat that has not decay, the material is still recognizable origin, coloured brown, and when crushed 75 fiber content remaining. Based on the level of fertility grade is divided into three categories. There are : • Eutrophic peat is a fertile peat rich material minerals and bases as well as other nutrients. Peat is relatively fertile peat are usually thin and are affected by river or sea sedimentation. 6 • Mesotrophic peat is have less fertile because it has content minerals and moderate bases. • Oligotrophic peat is peat infertile because of poor mineral and bases. The dome of peat and peat thickness which far from influence of rivers mud is usually classified as oligotrophic. Peat in Indonesia is largely classified as peat mesotrophic and oligotrophic Radjagukguk, 1997 in Subiksa, 2008. Peat eutrofik in Indonesia just a few and generally spread in coastal areas and along the river flow. Based on its formation environment, peat is distinguished by : • Ombrogen peat is peat formed in an environment only influenced by rain water. • Topogen peat is peat formed in an environment that has enrichment tide. Thus the peat topogen will be more rich in minerals and more fertile than the peat ombrogen. While according to the depth of peat can be divided into shallow peat 50- 100 cm, medium peat 100-200 cm, deep peat 200-300 cm, and very deep peat 300 cm. Peatland on Indonesia estimated approximately 20,6 million hectare. Widely spread of peatland give the meaning necessary for global custody ecosystem because about 50 percent from world tropical peatland, about 40 million hectare reside in the Indonesia area. But, in this time condition of forest and peatland in Sumatra and Kalimantan are continuously decrease. That its true, peatland has some important value both for having the character of extractive and also non extractive. As extractive material, peatland can be exploited as the resource, peat ash serve the purpose of fertilize, taken by humat acid, media plant, substance for the reclamation of dry farming. Upon which the non extractive, peat function as habitat of supporter of involving variety, that is as forestry farm, plantation and agriculture. Beside that, because its ability to store the water are very big which can reach 90 percent and its volume hence the peatland function as hidrologycal system for its surrounding area which is prevent floods in the rains, supply the water in dry season and prevent the water intrusion of the sea. Physical characteristics of peat are 7 important in its utilization foragriculture include water content, volume capacity bulk density, BD, the bearing capacity, subsidence, and irriversible drying. Peat soil water content ranged from 100 – 1300 of dry weight Muttalib et al., 1991 in Subiksa, 2008. This means that the peat can absorb water up to 13 times weight. Thus, to some extent, peat dome could drain water to the area around it. High water content cause BD to be low, peat becomes flabby and low holding power. Bulk density the top layer of peat varies between 0.1 to 0.2 g cm -3 depending on the level decomposition. Peat fibrik are generally located on the bottom layer has a bulk density lower than 0.1 gcm3, but coastal peat and peat in the path of the river flow can have bulk density 0.2 g cm -3 Tie and Lim, 1991 in Subiksa, 2008 because of the influence of soil minerals. Forest peatland in Indonesia has huge value in socio economic aspect. As food source, construction material and drinking water, peatland give the living for society. Otherwise, Naturally peatlands have a low fertility rate because low of hara materials and contain some organic acids which can be toxic to plants. However, those acids is an active part of the soil that determines the ability of peat to hold nutrients. Characteristics of organic acids will determine the chemical characteristic of peat. To reduce the adverse effect of organic acids that toxicity to the plants, can be performed by adding ingredients that contain a lot of cations polyvalent such as Fe, Al, Cu and Zn. Cations form the bond coordination with the organic ligands form a complex compound chelate. Therefore the materials containing polyvalent cations can be used as an ingredient amelioran peat Sabiham et al., 1997 in Subiksa, 2008. 2.2 Why we have to Exploit the Peatland area for Agriculture?