Growing area of sago palm and its environment

Abstract

Sago palms grow well on riverbanks, near lakes, and in wet soil. They can be found at 700 m elevation in PNG and are well adapted in marginal soils where cash crops cannot grow. Sago palms can grow from low flooded areas to uplands and in soils which are from very acidic to neutral. Sago is one of the most efficient carbohydrate-producing crops. Sago is distributed naturally from Melanesia in the South Pacific in the east (180°E. Long.) to India in the west (90°E. Long.) and from Mindanao in the north (10°N. Lat.) to Java in the south (10°S. Lat.). Sago populations in the world occupy 2.4 million ha. Temperature plays a key role in sago palm growth. The lowest temperature at which sago palms will grow is 15 °C. When temperatures are lower than 13 °C at the seedling stage, sago palms are not able to survive, and the mortality percentage increases. Moreover, fewer leaves are produced at low temperatures. The optimum relative humidity and sunlight intensity for sago palms are 90% and 900 j/cm2/day. The optimum rainfall for sago is 2000 mm per year. In addition, sago can grow when the location has less than two dry months and more than nine wet months. Sago palms can grow in various types of soils: (1) undeveloped soils, such as sulfaquents (sulfidic soil), hidraquents (waterlogged), tropaquents (tropical climate), fluvaquents (alluvial), and psammaquents (sandy soils), and (2) developed soils, such as tropaquepts, troposaprists of peatlands, tropohemists and sulfihemists (sulfuric soil and low pH), and thaptohistic fluvaquents. Sago palms thrive in swampy conditions where the pneumatophores are not submerged, where mineral nutrition and organic matter are high, and where the standing water is brown and slightly acidic. Such a habitat is suitable for the growth of microorganisms that benefit sago palm growth. Sago palms can also grow in swampy areas near the sea, as they are tolerant of salinity. Sago palms have avoidance tolerance to Na+. Excess Na+ is stored in the roots. Subsidence will occur after peatlands have been drained, and the process occurs very quickly. Subsidence is approximately 20-50 cm year-1 during the early building of a drainage network. Land clearing for agricultural purposes is usually accompanied by the draining of peatlands. Drainage negatively impacts the soil by decreasing the soil level, which triggers the land's unavailability for agricultural use. Sago palm plantations can be a solution to the degradation of peatlands due to the maintenance of the water level. Sago palms grow optimally in swampy and waterlogged conditions and peatlands. Due to the maintenance of the water level during the sago palm growing period, the degradation of peatlands can be avoided. Sago palm cultivation on peat soil will conserve not only water but also soil, so the environment will be maintained. Sago palms also support peatlands in storing carbon and minimizing greenhouse effects. Moreover, sago palms have the highest CO2 absorption as compared to other major crops.