contours of the peatland. Although the slope of peatlands is relatively shallow
(e.g. 50–100 cm/km) development of the drainage system without considering the
contours may lead to rapid drainage in some areas and pooling of water in others.
This may lead to difficulties to maintain even GWL without many water control
structures. Recent best practice has involved the development of drainage systems
linked to land contours—in which collection drains are dug along the contours as far
as possible. This will mean that the GWL along the canal is relatively even,
minimizing the need to add water control structures. This reduces the number of
water control structures needed and also means that the drains can be used for water
transport.
For plantations on peatland which did not design their drainage system based on
contours, the existing water management system can be adjusting by establishing
water zones which group nearby areas together, in which a common GWL is
maintained by establishing blocks or bunds along the zone boundaries. Water zoning
can be used to stabilize and control GWL—but needs to be designed through a
detailed hydrology and water management study.
18.5.2 Nutrient Management
The requirement of nutrients in oil palm is generally high in order to sustain longterm high yields (Parish et al. 2019a). The nutrients are immobilized in the growing
trunk of oil palm and removed through fresh fruit bunches (FFB). Unlike mineral
soils, depending on the type of peat, retaining the applied nutrients in peat is difficult
especially the highly required potassium nutrient due to low bulk density, high
infiltration rate and porosity. As GWL in peatland is maintained relatively high,
the chances of nutrients loss from the applied fertilizer through surface run off and
leaching are high during wet seasons. Peat contains high carbon, low nitrogen, low
available and total phosphorous, low magnesium and calcium and low potassium.
Imbalance of potassium and nitrogen by fertilizer application in peatland is common
in oil palms resulting in white stripe leaf symptom. Micro-nutrients requirement is
another important aspect for palms planted in peatland. Boron, copper and zinc are
considered routine micro-nutrients required for the palms. Recently in replanting,
iron deficiency has been reported; High yields are reported in peat with appropriate
balanced fertilization and agro-management practices.
The fertilizer requirement in palms planted on peatland is not the same as that of
mineral soils. An experienced agronomist should be engaged to draw annual fertilizer recommendations depending on the data on climate, field observation, palm age,
palm growth, potential FFB production and information of peat and palm leaf
nutrient statuses. Agronomists should draw annual fertilizer recommendations
based on the month of application, rates or dosage of individual fertilizer and total
tonnage of fertilizer required for the year. At the time of survey, a peat profile sample
should be collected and analysed for basic information of inherent characters such as
Loss of Ignition, pH, carbon, nitrogen, available and total phosphorous, cation
18 Role of the Roundtable on Sustainable Palm Oil (RSPO) in Tropical Peatland. . .
519
(e.g. 50–100 cm/km) development of the drainage system without considering the
contours may lead to rapid drainage in some areas and pooling of water in others.
This may lead to difficulties to maintain even GWL without many water control
structures. Recent best practice has involved the development of drainage systems
linked to land contours—in which collection drains are dug along the contours as far
as possible. This will mean that the GWL along the canal is relatively even,
minimizing the need to add water control structures. This reduces the number of
water control structures needed and also means that the drains can be used for water
transport.
For plantations on peatland which did not design their drainage system based on
contours, the existing water management system can be adjusting by establishing
water zones which group nearby areas together, in which a common GWL is
maintained by establishing blocks or bunds along the zone boundaries. Water zoning
can be used to stabilize and control GWL—but needs to be designed through a
detailed hydrology and water management study.
18.5.2 Nutrient Management
The requirement of nutrients in oil palm is generally high in order to sustain longterm high yields (Parish et al. 2019a). The nutrients are immobilized in the growing
trunk of oil palm and removed through fresh fruit bunches (FFB). Unlike mineral
soils, depending on the type of peat, retaining the applied nutrients in peat is difficult
especially the highly required potassium nutrient due to low bulk density, high
infiltration rate and porosity. As GWL in peatland is maintained relatively high,
the chances of nutrients loss from the applied fertilizer through surface run off and
leaching are high during wet seasons. Peat contains high carbon, low nitrogen, low
available and total phosphorous, low magnesium and calcium and low potassium.
Imbalance of potassium and nitrogen by fertilizer application in peatland is common
in oil palms resulting in white stripe leaf symptom. Micro-nutrients requirement is
another important aspect for palms planted in peatland. Boron, copper and zinc are
considered routine micro-nutrients required for the palms. Recently in replanting,
iron deficiency has been reported; High yields are reported in peat with appropriate
balanced fertilization and agro-management practices.
The fertilizer requirement in palms planted on peatland is not the same as that of
mineral soils. An experienced agronomist should be engaged to draw annual fertilizer recommendations depending on the data on climate, field observation, palm age,
palm growth, potential FFB production and information of peat and palm leaf
nutrient statuses. Agronomists should draw annual fertilizer recommendations
based on the month of application, rates or dosage of individual fertilizer and total
tonnage of fertilizer required for the year. At the time of survey, a peat profile sample
should be collected and analysed for basic information of inherent characters such as
Loss of Ignition, pH, carbon, nitrogen, available and total phosphorous, cation
18 Role of the Roundtable on Sustainable Palm Oil (RSPO) in Tropical Peatland. . .
519