clearly show that if nutrients and oxygen are supplied from the land surface, plants
can grow well even at high GWLs. The AeroHydro culture media enhance the
functions of plant roots to absorb nutrients and oxygen from the ground surface of
peatlands, where nutrients and oxygen become severely limiting factors. Furthermore, the media releases nutrients slowly so that most nutrients will be absorbed by
plants without leaving the planted area.
Until now, most peatlands have been managed with a drainage system to decrease
GWL, called drainage-based water management (drainage-based WM) (Chap. 2).
Instead of this drainage-based WM, an irrigation system to maintain a high
ground water level called “stock-based water management” (stock-based WM) is
proposed (Chap. 2). However, a stock-based WM system with a high GWL creates
challenges for oxygen availability and soil nutrient absorption without AeroHydro
culture technology.
7.3 Observation and Case Study on AeroHydro Culture
7.3.1 Case Studies on Oil Palm Growth at High GWL
It is widely believed that oil palm must grow at a low GWL (less than 40 cm). This
idea is mainly based on the assumption that oil palm species are adapted to more dry
conditions, and therefore, oil palm cannot grow in peatlands with high GWL.
However, there is an exception for oil palm growth even at high GWLs. Oil
palm in some plantations can grow well even at high GWLs. For example, an oil
palm plantation of United Plantations Berhad in Malaysia succeeded in growing oil
palm at a high GWL (less than 40 cm) in a tropical peatland. This oil palm plantation
became the world’s first certified producer of sustainable palm oil by the Roundtable
on Sustainable Palm Oil (RSPO) on 26th August 2008. One key component of their
system is land or soil surface management using natural compost and grass
mulching. Natural compost (piles of old fronds) and grass mulching maintain
wetness on the land surface, and the roots are distributed on the land surface. It is
accordingly assumed that the roots are supplied with enough O 2 even at high GWLs
and that the roots can absorb enough nutrients from the land surface (Fig. 7.4).
Another case of good oil palm culture practices under high GWL (less than
40 cm) is a small oil palm plantation located at Mega Timur Village, Sungai
Ambawang District, Kubu Raya Regency, Pontianak, Indonesia. The productivity
(fresh fruit bunches (FFBs)) of this plantation is approximately 35 ton/ha/year (very
high productivity). This farmer applies a unique technology for nutrient application:
(1) natural compost in the field (only piles of old palm fronds) and (2) chicken
manure and compost in netting bags. Oil palm roots grow into the natural compost
and the netted bags, and then the roots absorb nutrients with enough oxygen supplied
from the air. The roots are lateral roots but look like aerial roots (called aerial-like
roots, here). In addition, here, K
+ is supplied from sea water because of the lack of
symptoms of K deficiency in the leaves (Fig. 7.4).
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R. I. Wetadewi et al.
can grow well even at high GWLs. The AeroHydro culture media enhance the
functions of plant roots to absorb nutrients and oxygen from the ground surface of
peatlands, where nutrients and oxygen become severely limiting factors. Furthermore, the media releases nutrients slowly so that most nutrients will be absorbed by
plants without leaving the planted area.
Until now, most peatlands have been managed with a drainage system to decrease
GWL, called drainage-based water management (drainage-based WM) (Chap. 2).
Instead of this drainage-based WM, an irrigation system to maintain a high
ground water level called “stock-based water management” (stock-based WM) is
proposed (Chap. 2). However, a stock-based WM system with a high GWL creates
challenges for oxygen availability and soil nutrient absorption without AeroHydro
culture technology.
7.3 Observation and Case Study on AeroHydro Culture
7.3.1 Case Studies on Oil Palm Growth at High GWL
It is widely believed that oil palm must grow at a low GWL (less than 40 cm). This
idea is mainly based on the assumption that oil palm species are adapted to more dry
conditions, and therefore, oil palm cannot grow in peatlands with high GWL.
However, there is an exception for oil palm growth even at high GWLs. Oil
palm in some plantations can grow well even at high GWLs. For example, an oil
palm plantation of United Plantations Berhad in Malaysia succeeded in growing oil
palm at a high GWL (less than 40 cm) in a tropical peatland. This oil palm plantation
became the world’s first certified producer of sustainable palm oil by the Roundtable
on Sustainable Palm Oil (RSPO) on 26th August 2008. One key component of their
system is land or soil surface management using natural compost and grass
mulching. Natural compost (piles of old fronds) and grass mulching maintain
wetness on the land surface, and the roots are distributed on the land surface. It is
accordingly assumed that the roots are supplied with enough O 2 even at high GWLs
and that the roots can absorb enough nutrients from the land surface (Fig. 7.4).
Another case of good oil palm culture practices under high GWL (less than
40 cm) is a small oil palm plantation located at Mega Timur Village, Sungai
Ambawang District, Kubu Raya Regency, Pontianak, Indonesia. The productivity
(fresh fruit bunches (FFBs)) of this plantation is approximately 35 ton/ha/year (very
high productivity). This farmer applies a unique technology for nutrient application:
(1) natural compost in the field (only piles of old palm fronds) and (2) chicken
manure and compost in netting bags. Oil palm roots grow into the natural compost
and the netted bags, and then the roots absorb nutrients with enough oxygen supplied
from the air. The roots are lateral roots but look like aerial roots (called aerial-like
roots, here). In addition, here, K
+ is supplied from sea water because of the lack of
symptoms of K deficiency in the leaves (Fig. 7.4).
256
R. I. Wetadewi et al.