Peat soils have been paid attention regarding their existence in large area in tropical countries for agricultural development, which is related to satisfying the demand of carb9y6drate. Sago palm(Metroxylon sagu Rottb.) can produce 15-24 ton of starch ha-1 year －1, which indicates an extremely high yield of starch compared to other crops. Sago palm has an ability to withstand harsh environment of peat soils. There was a fact that a lower in starch production and slower in growth rate was observed in sago palms growing in peat soils, than those of grown in mineral soils, which was because of lower nutrient availability in peat soils. However, there are few researches studying nutrient status of peat soils for improving the growth and increasing the production of sago palm. This study concerns on nutrient status and gross N mineralization of peat soils for sago palm growth.

1. Compare to mineral soils in coastal lowland area, peat soils showed lower chemical properties, which indicated low soil pH, low total N and exchangeable NH4+ and low concentration of cations in soil. Compare to the effect volcanic activity or depression position, which enriched the elemental composition of inland peat, concentration of cations in seawater inversely, had little impact on the concentration of elements in soils in total and in exchangeable form.

2. The change of cations concentration in leaves of sago palms grown in coastal lowland area was not affected either by soil total cations or soil exchangeable cations. However, there was a significant effect of cations in soil solution on concentration of cation in the leaves.

3. Gross N mineralization was evaluated the kinetic parameters, namely: mineralization potential (N₀), apparent activation energy (Ea) and mineralization rate constant (k) values. The value of (N₀) ranged from 571-2445 mg kg^-1,with the average of 1150mg kg^-1. N₀ was not significantly affected by soil total N and total C content. Ea value ranged from 281-8181 J mol^-1, with the average of 2253 J mol^-1. Three levels of Ea were suspected to exist in peat soils, i.e.: peat soils with low Ea value, which less or same with 1000 J mol^-1, peat soils with mid Ea value which ranges of more than 1000 to about 3000 J mol^-1, and peat soils with high Ea value, which more than 8000 J mol^-1.

4. There was no significant influence of soil C/N ratio to k and Ea value of the peat soils, alkyl C/O-alkyl C ratio of peat soils has a negative influence on k value. There was no significant effect of hexosamine N/amino N ratio on the k value and Ea value of the soils.

5. A significant effect of N fertilizers on plant height and leaf formation has not been observed. Leaf samples of sago palms collected on December 1998 and 1999 did not show any significant effect of N fertilizer on the concentration of N in leaves. In contrast, significantly higher concentration of N was present in the samples of young leaves collected in June 2000 from the LP-100 and Urea treated palms than in the control palms.

和訳
　泥炭土壌は熱帯地方に広く分布し今後の炭水化物生産にとって重要な土壌である。サゴヤシは泥炭のように 湛水条件でも年間ヘクタールあたり15-20トンの炭水化物を生産する貴重な作物である。しかし、泥炭土壌での サゴヤシの生育は鉱質土壌に比較すると進度が遅く、年間生産量は低い。この理由は泥炭土壌が貧栄養条件に あることによる。そこで本研究では、サゴヤシ生産の基礎として泥炭土壌の栄養条件と真の窒素無機化を検討した。 得られた成果の概略は以下の通りである。

１．海岸沿いに発達する泥炭土壌の化学的性質は鉱質土壌と比較してpHが低く、全窒素量、交換性アンモニア 態窒素量および交換性塩基類含量が低い。

２．海岸沿いの低湿地に生育するサゴヤシの葉身中の塩基含量は土壌の全塩基含量や交換性塩基含量と関係が 認められなかった。しかし葉身中の塩基含量は土壌溶液中の塩基濃度の影響を受けていた。一方、土壌溶液中の 窒素濃度、交換性窒素濃度と葉身中の窒素濃度には一定の関係が認められなかった。

３．真の無機化を速度論的に解析した結果、可分解性有機態窒素量は571-2445 mgkg^-1であり、 平均で1150mgkg^-1　となった。活性化エネルギーは281-8181 J mol^-1で、平均 2253 J mol^-1であった。泥炭土壌の活性化エネルギーは多様であるので、大、中、小の３つのカテゴリーに わけた。

４．速度定数はalkyl C/O-alkyl C比との間には負の相関関係が認められた。一方、活性化エネルギーと alkyl C/O-alkyl Cには関係が認められなかった。hexosamine N/amino Nと無機化速度定数、活性化エネルギーとの 間には関係が認められなかった

５．施肥試験では施肥によってサゴヤシの生育（樹高、葉の展開速度）に影響が認められなかった。 また、葉身中の窒素濃度も施肥によって高まることはなかった。一方、施肥を継続した場合葉身の窒素濃度が上昇した。