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2.3 Potential and Management of Peatlands For Food Crops
According to Subiksa 2008 peatlands which can be used for food crops recommended on shallow peat 100 cm. Primary consideration is shallow peat
has a relatively higher fertility rates and have lower environmental risk than deep peat. Peatlands with a depth of 1,4 to 2 m classified as marginal suitability class
S3 for various kinds of crops. Marginal land in Indonesia found in both wetlands and dry land. The form
of peat wetlands, land acid sulfate and the tidal area of 24 million ha, while upland dry included ultisol reached 47.5 million ha of land and oxisol reached 18 million
ha Suprapto, 2003 in Yuwono, 2009. Millions of hectares marginal lands are scattered in several island, the prospect was good for development in agriculture
but it has not managed well. These lands has low fertility, so it necessary innovation in technology to fix the productivity.
Food crop cultivation in peatlands have to implement water management technology, match with the characteristics of peat and plant species. The function
of drainage is to remove excess water, creating conditions for respiratory unsaturated plant roots, and wash some organic acids. The shorter the interval
distance between the drainage ditch the higher crop yields. Although drainage is important for plant growth, but increasingly in the drainage channel will
increasing the rate of subsidence and peat decomposition. The management waterworks in the area of peat faces two conflicting
desires. First, desire to get rid of water drainage to lower the water level for the process of maturation and soil leaching and the desire to keep the water level in
order to maintain soil moisture and provide water supply irrigation. Fluctuation of water level in rivers and channels due to tidal movement, as well as fluctuations
in rainfall, the process of managing the water system in a swamp area becomes very complicated.
Water managements in peatland area influenced also by the hydraulic conditions boundary, such as the movement of rivers include tidal fluctuations,
water level fluctuation due to the influence of season rainy season and dry season, sea water intrusion, and the flow of the surrounding area.
10 Tidal elevation compare with the elevation of land hidrotopography will
largely determine the spatial pattern of the water. Water level movement on the coast is strongly influenced by tides. In areas near the estuary, changes in water
surface elevation was determined by the tides . In the area in the upper estuary, the transition area between the regions tidal and non tidal area, water surface
elevation changes not only affected by the tides but also affected by discharge coming from upstream. On the upstream side of the river which is not influenced
by tides, changes in water elevation is determined by the upstream river discharge. As we know, there are four categories hydrotopography, there are swamps
overflow type A, B, C and D. Viewed from the aspect of irrigation, the overflow swamp type A and B is the swamp with the potential to be developed for the
purpose of cultivating rice that requires drainage, but this area has a limitation in the process of disposal of drainage due to limited time during a low tide only.
While from the aspect of drainage, peatland type C and D will be easier to get rid of stagnant water, simplifying the process of land development. However,
if there excessive, will decrease the nutrients that eventually the land will become unproductive.
2.4 Remote Sensing for Peatland
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