B.H. Purwanto, K. Kakuda, and H. Ando
Faculty of Agriculture, Yamagata University, 997-8555, Tsuruoka, Yamagata, Japan
Keywords: coastal lowland, distance from sea, bulk density, soil nutrients, leaf nutrients
Abstract
Sago palm has been recognized to survive in peat soils, which have chemical and physical constraints such as waterlogged condition, extremely acid, low status of macronutrients and micronutrients, and low bulk density. This palm is distributed on peat soils and mineral soils of coastal lowland area. It was reported that distance from sea influenced soil solution composition of peat soils in coastal lowland area and shorter distance from sea contributed higher content of Na and Mg. These differences might be reflected by nutrient composition in leaf of sago palm.
Objective: To clarify nutrient status of peat soils in coastal lowland area in relation to distance from sea and its contribution to nutrient in leaf of sago palm
Materials and Methods: Location: Mukah, Sarawak, Malaysia and Selat Panjang, Tebing Tinggi, Indonesia. Sampling interval: Soil and leaf samples were taken from different distance from sea at about 500 m interval along 3 km sampling transects. Analytical procedure: Total N in soil (Kjeldahl method), exchangeable cations (NH4OAc-extract), extractable Fe (DTPA-extract), Zn and Cu in soils (0.1 N HCl extract) and concentration of N (Kjeldhal method), K, Ca, Mg, Na, Fe, Zn and Cu in leaf (wet ashing by HNO3 + HClO4)
The results showed that:
1. The soil bulk density greatly varied among the soils.
Hence, concentration of nutrient in soils should be expressed in volume
basis to get a fair comparison among the soils.
2. Significant relationship between total?N in soils
expressed in volume basis and distance from sea was observed, and on the
contrary neither amount of exchangeable cations nor minor nutrients in
soils expressed in volume basis were affected by distance from sea.
3. There was no relationship between amount of exchangeable
Mg and extractable Fe, Zn and Cu in soils expressed in volume basis and
concentration of those nutrients in leaf. In contrast, total N in soils
expressed in volume basis significantly influenced concentration of N in
leaf. Significant influence of amount of exchangeable Ca, K, and Na in
soils expressed in volume basis on concentration of those nutrients in
leaf was also observed