Coconut: Acid Sulphate Soils
The acid sulphate soils which are in the coconut areas in our Group of estates were mapped according to the soil identification key drawn up by Paramanathan (1981) and subsequently modified as per Table 1.
(AFTER PARAMANATHAN)
Horizonation and Nature of Subsoil |
A/C or O/A/CSulfidic Materials |
A/B/C |
A/B/C |
A/B/C |
A/B/C |
A/BC/C or A/C or O/A/C Non-Sulfidic Materials |
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Depth to sulfuric Horizon/C Horizon |
High ‘n’ value |
Low ‘n’ value |
50 cm |
100 cm |
100 cm |
50-100 cm |
50 cm |
High ‘n’ value |
Low ‘n’ value |
|||||||
Colour Group |
Yellow (Jarosite) |
Olive |
Brown |
Red |
Olive |
Brown |
Red |
Olive |
Brown |
Red |
||||||
Properties of subsoil |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Matrix light-gray coarse angular blocky sticky few pieces of woods |
mKranji* |
mMerbok |
mparit |
mTongkang |
mBernam |
mPerepat |
mParit Botak(B) |
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e Briah |
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mKuala Perlis 1 |
bTelok 2 |
mKangkong |
eKechai Kundor |
eChengai |
mSedaka |
mRotan |
mTebengau |
mSerong |
mBakau |
|||||||
eCarey |
mKundor |
eKangar |
mKuala Kedah |
mPiandang |
||||||||||||
fTualang |
fIdris |
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Matrix bron fine/ medium subangular blocky, friable many pieces of wood |
Linau |
bSedu2 |
bJawa |
bSelangor |
bSabrang |
bSerkat |
blinau |
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bGuar1 |
NOTES: | |||
m – |
Marine deposit
|
* – |
Conductivity high (>2.0 mm nos/cm) with 50 cm depth
|
e – |
Estuarine deposit
|
* – |
Marine clay (C) with 50 cm
|
b – |
Brackish water deposit
|
2 – |
Marine clay between 50-100 cm
|
f – |
Fluviatile, often riverine over marine
|
Our experience with coconuts in the acid sulphate areas and other coastal soil areas is limited to the soil series shown in Table 2.
Horizonation |
A/B/C |
A/B/C |
A/B/C |
||||
Nature of subsoil |
Sulfuric |
Cambic |
Cambic |
||||
Colour group |
Yellow |
Brown |
Brown |
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Depth (cm) to sulfuric or C horizon |
50 |
100 |
100 |
100 |
100 |
50-100 |
50-100 |
Soil Series |
SEDU |
JAWA |
BERNAM |
BRIAH |
SELANGOR |
PEREPAT |
SABRANG |
Area (ha) |
252 |
86 |
617 |
718 |
97 |
200 |
204 |
No. of estates |
2 |
2 |
1 |
3 |
3 |
1 |
2 |
Out of 2174 ha of coconuts (mostly underplanted with cocoa), only 338 ha (15 per cent) are on acid sulphate soils of the Sedu and Java Series.
The coconut areas on acid sulphate soils are located in the Bagan Serai (Estate 1) district, and as discussed later, the problem is compounded by difficulties in water management and the markedly seasonal rainfall pattern.
A comparison of the coconuts and cocoa grown on acid sulphate soils in this estate and comparable areas on two other estates on Sabrang and Briah series (Estate 2 in Kuala Kurau district) and on Bernam/Selangor series (Estate 3 in Sabak Bernam district) is given in this paper.
Rainfall patterns for the estates are shown in Appendix 1.
APPENDIX 1. RAINFALL PATTERNS (1971 – 1982) IN COCONUT ESTATES
Month
|
Estate 1 Bagan Serai |
Estate 2 Kuala Kurau |
Estate 3 Sabak Bernam |
|||
Mean |
Years |
Mean |
Years |
Mean |
Years |
|
January |
71 |
8 |
59 |
10 |
164 |
5 |
February |
114 |
4 |
113 |
6 |
150 |
3 |
March |
104 |
6 |
103 |
7 |
131 |
4 |
April |
241 |
2 |
224 |
2 |
231 |
2 |
May |
156 |
4 |
142 |
2 |
226 |
2 |
June |
116 |
5 |
129 |
4 |
109 |
6 |
July |
125 |
6 |
138 |
6 |
162 |
5 |
August |
130 |
5 |
139 |
6 |
140 |
3 |
September |
239 |
2 |
271 |
1 |
220 |
2 |
October |
304 |
0 |
320 |
0 |
317 |
1 |
November |
194 |
3 |
186 |
3 |
310 |
0 |
December |
131 |
4 |
121 |
5 |
257 |
2 |
Total |
1925 mm |
|
1945 mm |
|
2417 mm |
|
Reference
Chew P.S., Kee K.K. and Ooi L.H. 1984. Management of coconuts and cocoa on acid sulphate soils. The Planter. Incorporated Society of Planters, Kuala Lumpur 60 (704) : 483-498.
Note: The full list of references quoted in this article is available from the above paper.