Chemical and spectroscopy of peat from West and Central Kalimantan, Indonesia in relation to peat properties

Reclamation of peat requires knowledge of different properties, including those that put emphasis on the nature of the peatswamps rather than the peat material itself. Peat is derived from the remains of plants and animals and peatland occurs normally in flooded areas, such as tidal swamp, flat areas and leeves. Under these condition the populatin of aerobic microorganisms drop drastically and only anaerobic microorganism are able to survive in large numbers. Peatlands in Indonesia cover an area of appoximately 27 million hectares mostly in Sumatra, Kalimantan, and Irian Jaya (Radjagukguk, 1992). Most of this peatland is ombrogenous while topogenous peat only occurs in isolated locations. In Central Kalimantan, peat varies greatly in thickness and covers an area of 18,615 km2 or 18.14% of the total area (153,660 km2) (Hanudin and Rusmarkam, 2001). West Kalimantan reviewed in terms of the distribution of peat area is approximately 1.73 million hectares (8.49% of the peat bogs area in Indonesia), compared to the extent of West Kalimantan province of around 14.680.700 ha land area, means that the area of peat 11,79 %t of West Kalimantan areas (Noor and Heyde, 2007)

 In their natural state peat bogs are saturated with water. One of the first steps in agricultural development is to drain the bog. Ditches and subsurface drains are used to enhance the movement of water from the peat, thereby lowering the water table and aerating the peat soil. Aeration of the soil is necessary for plant growth, aerobic microbial processes, and to ease the operation of farm machinery. Before vegetable production can begin, the peat soil must also have its pH and fertility adjusted. The drainage, liming, fertilization and tillage required for vegetable production radically alter the physical, chemical, and biological properties of the peat. Under vegetable production the growth and accumulation of peat stops and decomposition is accelerated. On peat soils, nutrient management is complicated by the soil's naturally low fertility, high carbon content, and very acid pH. Poor nutrient management can result in crop failure or make the cost of producing a good crop economically unsustainable. 

For soil improvement, identifying the problems associated with peat soils is necessary. This can reduce the life of the peat soil – shrinkage can continue until there is no peat left – and compromise the status of adjacent peat lakes and wetlands. For peat farming to be successful and profitable in the long term, farmers must find a balance between maintaining the water table at levels low enough to optimize production, yet high enough to minimize shrinkage and the impact on adjacent wetlands and peat lakes. Current efforts to restore peatlands at a large scale therefore require low cost and high throughput techniques to monitor the evolution of organic matter. Methods to analyze SOM composition include FT-IR or nuclear magnetic resonance (NMR) spectroscopy. In FT-IR spectra, absorption bands at distinct wave numbers indicate the presence of functional groups with known chemical compositions and properties. The intensity of the aliphatic (CH) absorption band in DRIFT and FT-IR spectra was used to estimate the hydrophobic character of soil samples (Capriel et al., 1995; Capriel, 1997; Hsu and Lo, 1999; McKissock et al., 2003). The composition of SOM may, in addition to the SOM content, be used for studying quantitative effects of different management practices or even land use changes on soil properties. A detailed analysis of the SOM-composition (Ellerbrock et al., 1997) using Fourier Transform infrared (FT-IR) spectroscopy showed that the content of the carboxyl-and hydroxyl-groups in the SOM pyrophosphate extracts was higher in the plots fertilized with cattle manure than in those that received straw+mineral nitrogen.