ecosystems, such as wetlands, lowlands, mangroves, sandy podzolic soils, and acid
sulfate soils.
7.2 Key Concepts of AeroHydro Culture
7.2.1 The Mystery of Plant Growth in Native Tropical
Peatlands
A native tropical peatland is a mysterious ecosystem. Plant growth productivity
(biomass/ha/year) in peatlands is excellent compared with that in mineral soils.
However, oxygen and nutrients cannot be supplied from peatlands or peat water
(Chap. 1). As plant growth requires both oxygen and nutrients, the poor oxygen and
nutrient conditions should seriously limit plant growth. Plant growth in peatlands
therefore presents a physiological contradiction and an ecological mystery.
It was long suspected that plants could not grow well in oxygen- and nutrientpoor environments; therefore, tropical peatlands have been imprudently developed
by digging canals to drain the water, which has been standard practice for a long time
(more than 100 years). This has resulted in global-scale disasters due to peatland
ecosystem destruction, causing enormous amounts of CO 2 emissions from peat fires
and peat oxidation by microorganisms, together with biodiversity losses and water
reservoir losses.
Here, the main question behind the function of tropical peatlands is “How does
excellent plant growth occur under extremely low oxygen/nutrient conditions?”
Thus, we need an ecological Sherlock Holmes to provide a well-reasoned answer
to this question.
7.2.2 Key Idea of AeroHydro Culture Derived from Native
Peatland Forests
Oxygen is the most serious limiting factor on plant growth under hydrological
conditions. Hydroculture is an excellent technology for studying the effects of
various nutrients and environmental conditions on plant growth and potential productivity. In hydroculture, O 2 must be supplied to the plants by bubbling air using a
compressor. Otherwise, even rice growth becomes poor or stops. By bubbling air
through capillaries into the water, small bubbles form in the water. The bubbles are
retained for a long time and then supply O 2 to plant roots. As nutrient absorption
mechanisms are energy-dependent, O 2 supply is essential for root metabolism. Thus,
we now understand that O 2 supply is an essential factor for nutrient absorption even
in native peatlands with high ground water levels. Additionally, we now understand
that if nutrients are applied by chemical fertilizers to peatlands, plant roots cannot
absorb these nutrients under high GWL.
7 Principles of AeroHydro Culture
251
sulfate soils.
7.2 Key Concepts of AeroHydro Culture
7.2.1 The Mystery of Plant Growth in Native Tropical
Peatlands
A native tropical peatland is a mysterious ecosystem. Plant growth productivity
(biomass/ha/year) in peatlands is excellent compared with that in mineral soils.
However, oxygen and nutrients cannot be supplied from peatlands or peat water
(Chap. 1). As plant growth requires both oxygen and nutrients, the poor oxygen and
nutrient conditions should seriously limit plant growth. Plant growth in peatlands
therefore presents a physiological contradiction and an ecological mystery.
It was long suspected that plants could not grow well in oxygen- and nutrientpoor environments; therefore, tropical peatlands have been imprudently developed
by digging canals to drain the water, which has been standard practice for a long time
(more than 100 years). This has resulted in global-scale disasters due to peatland
ecosystem destruction, causing enormous amounts of CO 2 emissions from peat fires
and peat oxidation by microorganisms, together with biodiversity losses and water
reservoir losses.
Here, the main question behind the function of tropical peatlands is “How does
excellent plant growth occur under extremely low oxygen/nutrient conditions?”
Thus, we need an ecological Sherlock Holmes to provide a well-reasoned answer
to this question.
7.2.2 Key Idea of AeroHydro Culture Derived from Native
Peatland Forests
Oxygen is the most serious limiting factor on plant growth under hydrological
conditions. Hydroculture is an excellent technology for studying the effects of
various nutrients and environmental conditions on plant growth and potential productivity. In hydroculture, O 2 must be supplied to the plants by bubbling air using a
compressor. Otherwise, even rice growth becomes poor or stops. By bubbling air
through capillaries into the water, small bubbles form in the water. The bubbles are
retained for a long time and then supply O 2 to plant roots. As nutrient absorption
mechanisms are energy-dependent, O 2 supply is essential for root metabolism. Thus,
we now understand that O 2 supply is an essential factor for nutrient absorption even
in native peatlands with high ground water levels. Additionally, we now understand
that if nutrients are applied by chemical fertilizers to peatlands, plant roots cannot
absorb these nutrients under high GWL.
7 Principles of AeroHydro Culture
251