Response of Sago Palm (Metroxylon sagu Rottb.) Cultivated on Tropical Peat
Soils to N Fertilizers
Benito H. Purwanto, Ken-ichi Kakuda, and Ho Ando
Faculty of Agriculture, Yamagata University
Sago palms (Metroxylon sagu Rottb.) are important source of carbohydrate
in Southeast Asia and New Guinea. Sago palms growing in peat soils are observed
to grow more slowly and to show lower production than palms growing in mineral
soils. This difference is related to physical and chemical constraints of
peat soils. Therefore, addition of nutrients to peat soils might accelerate
growth and improve productivity of the palms. However, the effect of addition
of soluble N fertilizer on foliar concentration of N and growth of the palms
was reported insignificant. Controlled release N fertilizer, which is capable
of providing a more permanent source of available N might promote the growth
of sago palm.
Objective: to investigate the influence of N fertilizer on the growth performance
of sago palm on peat soils.
Materials and Methods: Study site: Tebing Tinggi, Indonesia. Treatments:
controlled release N (LP-100), urea, and control, with 6 palms per treatment.
Application rate of fertilizers: LP-100 or urea was applied every 6 months
each at a rate of 500 g N per plant per application. Parameters: Leaf formation,
plant height, and foliar concentration of N.
Results:
1. Insignificant effects of N fertilizers on plant height and leaf formation
were observed. The leaf samples collected in 1998 and 1999 did not reveal
any significant effects of N fertilizer on the foliar concentration of N.
2. A significantly higher concentration of N (p〈 0.01) was present in young
leaves collected in 2000 from the LP-100- and urea-treated palms than the
control palms.
3. There was no significant difference in the foliar concentration of N between
the LP-100 and urea treatments.
This study indicated that sago palms not supplied with N fertilizers are
not capable of maintaining N levels in leaves. This situation may hinder
the physiological function of the leaf, which in turn could retard growth
optimization and starch accumulation.
講演要旨一覧に戻る
栽培土壌ホームページへ戻る