Society of America Journal 54, 1298-1304.
. Soil Science Society of America
Proceedings 35, 33-38.
Syers JK, Browman MG, Smillie GW, Corey RB (1973) Phosphate
sorption by soils evaluated by the Langmuir adsorption equation. In Thai soils, kaolin and sesquioxides are abundant constituents and are especially abundant
in upland soils in the north-east, lower north, and peninsular south,
covering about 47% of the total area of the country (Suddhiprakarn et
al. 2). Reactions of soil with applied P depend to a large extent on
mineralogy and texture (Uehara and Gillman 1981). 1987). Norrish and Taylor (1961) concluded that
DCB-extractable Fe and Al in Australian soils originated from Fe oxides,
which in their research was mostly goethite.
The P sorption data fitted to the Langmuir (plotted c v. Klong Chak (Kc) SGCL 3.2
11. Chumphon (Cp) Sawee district, Chumphon 10[degrees]15’59″
Holford ICR, Wedderburn RWM, Mattingly GEG (1974) A Langmuir
two-surface equation as a model for phosphate adsorption by soils.
Journal of Soil Science 25, 242-255.
These soils are highly weathered, nutrient-depleted, and infertile so that P inputs are needed to sustain crop yields (Greenland 1981).
Phosphorus sorption by most tropical soils is usually attributed to
kaolin and oxides of iron and aluminium although Al-OM complexes can
play a major role in some acid soils (Singh and Gilkes 1992). 1. 1993; Agbenin 2003) but this association has not
been demonstrated for Thai soils.
Phosphate sorption coefficients in relation to soil properties
Uehara G, Gillman GP (1981) ‘The mineralogy, chemistry, and
physics of tropical soils with variable charge clays.’ (Westview
Press: Boulder, CO)
[FIGURE 6 OMITTED]
[FIGURE 2 OMITTED]
x = a[x.sub.m]c/(1 + ac)
There were no significant relationships between Langmuir Xm or
Freundlich b and either soil pH or OM (Table 2). Sadao (Sd) C 0.7
Particle size distribution in soils was determined by the pipette method (Kilmer and Alexander 1949; Day 1965). The energy of P sorption (Langmuir
coefficient a and Freundlich b) is not closely related to any soil
property. Klong Thom (Km) 99[degrees]17’28″ 2-3 Palm
3. The Freundlich k coefficient
for subsoils (median 288 [micro]g/g) is generally higher than for
surface soils (median 112 [micro]g/g). The lack of a close relationship
possibly reflects the diverse range of surfaces at which sorption occurs
and the diverse processes (energies) that are involved on these surfaces
and at different equilibrium solution P concentrations. (Ed. Yasothon (Yt) 103[degrees]0’43″ 2-3 Mixed deciduous
8. 1987; Singh and Gilkes
1991 ; Sanyal et al. Chumphon (Cp) 99[degrees]3’47″ 3-4 Coconut
10. Chiang Khong (Cg) Doi Saket district, 18[degrees]53’42″
Soil series Longitude Slope Land use
1. Chiang Khong (Cg) 99[degrees]13’15″ 2-3 Mixed deciduous
Soil series Textural Avail. Pak Chong (Pc) C 24.7
12. Soil Science Society of
America Journal 67, 589-595.
Borggaard OK (1983) The influence of iron oxides on phosphate
adsorption by soil. The highest values of
[Fe.sub.d] for Thai soils are for soils developed on basalt (range 26-74
g/kg, median 48 g/kg) followed by soils on shale/limestone (10-47 g/kg,
19 g/kg), sandstone (4-36 g/kg, 8 g/kg), and granite (4-16 g/kg, 7
Kilmer VJ, Alexander LT (1949) Method of making mechanical analysis
of soils. The Freundlich
k value is also closely related to SSA (r = 0.86). Extraction of soils with
DCB and oxalate is considered to be reasonably specific for crystalline
Fe ([Fe.sub.d]) and amorphous/poorly crystalline Fe ([Fe.sub.o]),
respectively, but these extractants may not be as specific for
corresponding Al compounds (McKeague et al. P sorption
capacity is very closely related to dithionite- and oxalate-extractable
Al and surface area; therefore, [Al.sub.d] or [Al.sub.o] could be used
as a routine soil test for predicting P sorption as a component of land
capability evaluation practice. In
‘Proceedings of a Scientific Workshop on Diffuse Pollution in
Subtropical and Tropical Developing Countries and Its Abatement’.
Bangkok, Thailand. FE Khasawneh) pp. Yasothon (Yt) LS 2.0
8. Thai Muang (Tim) 98[degrees]20’14″ 5-6 Para rubber
15. Soil Science 68, 15-24.
Anjos LH, Fernandes MR, Pereira MG, Franzmeir DP (1998) Landscape
and pedogenesis of an Oxisol-Inceptisol-Ultisol sequence in Southern
Brazil. Australian Journal of
Agricultural Research 18, 601-612. Surin (Su) Khonburi district, 14[degrees]29’34″
‘Methods of soil analysis. Phosphate sorbed was calculated from the
difference between P added and P in the equilibrium solution.
Greenland DJ (1981) ‘Characterization of soils, in relation to
their classification of soils, in relation to their classification and
management for crop production: examples from some areas of the humid
tropics.’ (Clarendon Press: New York)
The Freundlich k coefficient, which is a measure of reactive
surface area (abundance of sorption sites) (Singh and Gilkes 1991;
Burkitt et al. CA Black) pp. The pH(KCl) values were lower (range 3.3
5.6, median 3.8) than those measured in water, indicating that the clay
minerals in the soils have a negative charge. Wiriyakitnateekul (A,B), A. Pathiu (Ptu) C 6.7
14. Although SSA provides
an excellent prediction of [x.sub.m] for Thai soils, the SSA procedure
is expensive and slow so it is preferable to predict P sorption maximum
[FIGURE 5 OMITTED]
Barrow NJ (1978) The description of phosphate adsorption curves.
Journal of Soil Science 29, 447-462.
Siradz SA (1985) Distribution, properties and phosphorus
requirements of soils of the Cobiac valley, Darling Range Western
Al may be present in the structure of iron oxides, in kaolin, or other
clay minerals and Al-OM complexes. But as 73%
of the variation in P sorption maximum can be explained by Aid alone
incorporation of more variables (and costly laboratory analyses) is not
Phosphorus sorption studies
Dithionite-citrate-bicarbonate (DCB) extractable Fe and Al
([Fe.sub.d] and [Al.sub.d]) were determined following the procedure of
Mehra and Jackson (1960). This is consistent with the findings of
Siradz (2000) for Indonesian red soils. Most of these
values were 0.1, which indicates that crystalline iron oxides are
dominant for these soils (Fitzpatrick and Schwertmann 1982). Physical and mineralogical
methods’. Pak Chong (Pc) Pak Chong, Nakhon 14[degrees]37’47″
12. The relationship between [x.sub.m] and [Al.sub.o] was
slightly improved, with [R.sup.2] increasing from 0.62 to 0.64 when the
data of the Tha Mai soil series, which are outliers, were excluded.
Conversely, [R.sup.2] for the relationship of [x.sub.m] with [Fe.sub.o]
decreased from 0.57 to 0.43. 2002), ranged from 27 to 1364 [micro]g/g, with a median
of 220 [micro]g/g, thus resembling Western Australian soils (k, range
1-1681 [micro]g/g) (Singh and Gilkes 1991) and Indonesian red soils (k,
range 388-1569 [micro]g/g) (Siradz 2000). Soil
Science Society of America Proceedings 37, 358-363.
Norrish K, Taylor RM (1961) The isomorphous replacement of iron by
aluminium in soil goethite. This indicates that the iron oxides in
the soils developed on basalt have a high degree of crystallinity
compared with the other soils.
The Freundlich equation is as follows (Barrow 1978):
The Langmuir adsorption coefficient, a, ranged from 0.5 to 15.0
mL/[micro]g, with a median of 3.6 mL/[micro]g. Hang Chat (Hc) 99[degrees]17’55″ 3 Tamarind
18. Krabi (Kbi) SCL 0.7
9. Ammonium oxalate extraction in the dark was
used to estimate non-crystalline and poorly crystalline Fe and Al
compounds ([Fe.sub.o] and [Al.sub.o]) (Rayment and Higginson 1992).
Langmuir [x.sub.m] and Freundlich k, which are both measures of
maximum P sorption capacity, were closely and positively related to
[Fe.sub.d], [Fe.sub.o], [Al.sub.d], [Al.sub.o], clay percentage, and SSA
(Table 2). 1987). Soil Science Society of America Proceedings 24, 420-421.
Barrow (1978) has shown that previously sorbed P should be taken
into account in P-fertilised soils when fitting equations to sorption
data for freshly added P. Stepwise correlation equations for predicting P sorption
maximum ([x.sub.m]) from some soil properties for Thai soils (n = 42)
Step Equation [R.sup.2]
1 109.19 + 0.86% [Al.sub.d] 0.73
2 45.33 + 0.58% [Al.sub.d] + 0.40% [Al.sub.o] 0.81
3 45.45 + 0.74% [Al.sub.d] + 0.38% 0.82
[Al.sub.o] -0.17% [Fe.sub.o]
4 40.35 + 0.63% [Al.sub.d] + 0.41% [Al.sub.o] 0.83
-0.20% [Fe.sub.o] + 0.13% [Fe.sub.d]
(B) Present address: Office of Science for Land Development, Land
Development Department, Chatuchak, Bangkok 10900, Thailand.
Phosphorus sorption coefficients
Beauchemin S, Samard RR (2000) Phosphorus status of intensively
cropped soils of the St. J. Communications in Soil Science and
Plant Analysis 30, 1013-1024.
Pena F, Torrent J (1984) Relationships between phosphate sorption
and iron oxides in Alfisols from a river terrace sequence of
Mediterranean Spain. Part 1. The lowest
median value of [Fe.sub.o]/[Fe.sub.d] for Thai soils is for soils
developed on basalt (median [Fe.sub.o]/[Fe.sub.d] = 0.06), increasing in
the sequence sandstone ([Fe.sub.o]/[Fe.sub.d] = 0.09) granite
([Fe.sub.o]/[Fe.sub.d] = 0.10) shale/limestone
([Fe.sub.o]/[Fe.sub.d] = 0.12). Field information for soils used in this publication
LS, Loamy sand; SL, sandy loam; SC, sandy clay; SCL, sandy clay loam;
SiL, silt loam; C, clay; CL, clay loam; VG, very gravelly, SG, slightly
gravelly; Co, coarse
Soil series Location Latitude
1. (ASA/SSSA: Madison, WI)
Results and discussion
Suddhiprakarn A, Kheoruenromne I, Sindhusen P, Yoothong K (1985)
Clay minerals and iron oxides of selected red and yellow soils in
north-east plateau and south coast, Thailand. Sawi (Sw) Khiri Ratthanikhom 9[degrees]1’15″
7. The values of [Fe.sub.o]/[Fe.sub.d] for the Thai
soils ranged from 0.01 to 0.28, with a median of 0.09. Australian Journal of
Soil Research 40, 497-513.
[FIGURE 8 OMITTED]
Poudal DD, West LT (1999) Soil development and fertility
characteristics of a volcanic slope in Mindanao, the Philippines. Soil Science and Plant Nutrition 35,
Udo EJ, Uzu FO (1972) Characteristics of phosphate adsorption by
some Nigerian soils. Kohong (Kh) 100[degrees]25’18″ 2-5 Para rubber
2. The [Fe.sub.o] values for the Thai
soils were similar to those for Indonesian red soils (0.4-12.4 g/kg)
(Siradz 2000) and quite similar to values for Oxisols from southern
Brazil (median 2.5 g/kg) (Anjos et al. Applied Clay Science 11, 357-371. Soil pH was determined for
a 1:1 soil:solution ratio using both distilled water and 1 M KCl
(Natural Resources Conservation Service 1996) and organic carbon by
Walkley-Black titration (Walkley and Black 1934). Chalong (Chl) 99[degrees]18’47″ 2-3 Para rubber
16. The pH(water) values ranged from 3.9
to 6.3 with a median of 4.7. 1985; Yoshinaga et al. 6. Geoderma 27, 335 347. Beauchemin and Samard (2000)
considered that the greater P sorption capacity of subsoils is due to
their greater clay content. 8,
demonstrating the strength of these relationships and that there is no
systematic deviation of data for any parent material from the regression
lines. Ao Luk (Ak) 98[degrees]55’51″ 5 Fruit trees
1. Average [x.sub.m] values follow the sequences
basalt [approximately equal to] shale/limestone granite
Mosugu ME, Chude VO, Esu IE, Parmwang TK, Malgwi WB (1999) Contents
and profile distribution of three forms of free iron oxides in three
Ultisols and an Alfisol in Nigeria. Pak Chong (Pc) 101[degrees]17’38″ 2-3 Custard apple
12. 1973; Holford et al. Site information, soil
classification, and interpreted parent materials are given in Table 1.
The soil samples were air-dried, crushed using a ceramic mortar and
pestle, and then passed through a 2-mm stainless steel sieve.
Sjarif S (1990) Some characteristics of Andosols from western
Indonesia. P sorption by soils developed on basalt conforms less well to
both Langmuir (linear regression coefficient r, range 0.88-0.99, median
0.99) and Freundlich (r, range 0.71-0.99, median 0.92) equations
compared with soils on other parent materials.
Borling K (2003) Phosphorus sorption, accumulation and leaching:
Effects of long-term inorganic fertilization of cultivated soils. More than 70% of the
soils were acidic, with pH 5.0. Sawi (Sw) 99[degrees]3’24″ 4-5 Para rubber
7. Sawi (Sw) SL 2.6
7. Phuket (Pk) 99[degrees]18’30″ 3-4 Para rubber
17. Chumphon (Cp) VGSL 1.0
10. doi: 10.1016/0016-7061 (82)90022-2
where x is amount of phosphate sorbed ([micro]g/g soil), c is P
concentration in the equilibrium solution ([micro]g/mL), k is an
empirical coefficient which is a measure of total sorption surface, and
b is an empirical coefficient related to the energy of sorption.
Dithionite- and oxalate-extractable iron and aluminium
Typical P sorption isotherms for the Thai soils, including those
with the highest and lowest P sorption capacities for each parent
material, are given in Fig. 122-132.
The objectives of this study were to determine the accuracy of
predictions of P sorption by Thai soils based upon values of dithionite-
and oxalate-extractable Fe and Al.
(A) Department of Soil Science, Kasetsart University, Bangkok
The amounts of DCB- and oxalate-extractable Al were similar, with
median values of 1.6 and 0.95 g/kg, respectively (Fig. doi:
Yoshinaga N, Yoshiro K, Makoto N (1989) Mineralogy of red- and
yellow-colored soils from Thailand. Krabi (Kbi) 98[degrees]45’30″ 4-5 Para rubber
9. Soil Science
Society America Proceedings 38, 250-255.
Rayment GE, Higginson ER (1992) ‘Australian laboratory
handbook of soil and water chemical methods.’ (Inkata Press:
Singh B (1991) Mineralogical and chemical characteristics of soils
from south-western Australia. doi: 10.1016/S0003-2670(00)88444-5
Concentrations of Fed in soils ranged from 4 to 74 g/kg, with a
median of 16.3g /kg. 263-310. Fang Danag (Fd) Tha Chang district, 9[degrees]12’49″
6. Soil Science 119, 167-177.
Loganathan P, Isiriman NO, Nwachuku DA (1987) Phosphorus sorption
by Ultisols and Inceptisols of Niger delta on southern Nigeria. Mae Taeng (Mt) Wang Thong district, 16[degrees]46’37″
22. Tha Mai (Ti) Tha Mai district, 12[degrees]38’36″
19. There are
close positive relationships between P sorption and the abundance of
crystalline (dithionite) and amorphous (oxalate) iron oxides in many
soils from diverse environments (Ballard and Fiskell 1974; Borggaard
1983; Pena and Torrent 1984; Loganathan et al. The sites are nearly flat to
undulating, with slopes of 2-8% and are mostly used for agriculture.
These soils are classified as belonging to the kaolinitic mineralogical
classes of Ultisol, Oxisol, and Alfisol. (USDA: Washington, DC)
Oxalate-extractable Fe concentrations ranged from 0.2 to 13.8 g/kg,
with a median of 1.5 g/kg (Fig. However, other differences between surface
soils and subsoils include abundant organic matter in topsoils, which
can bind onto clay and sesquioxides and inhibit sorption of phosphate
(Sample et al. Soil Science 157, 36-45.
[FIGURE 1 OMITTED]
Manuscript received 21 February 2005, accepted 16 June 2005
Sanyal SK, De Datta SK, Chan PY (1993) Phosphate
sorption-desorption behavior of some acidic soils of South and Southeast
Asia. Lopez-Hernandez and Barnham (1974) reported
that there was no significant relationship between OM and P sorption in
some British and tropical soils, as did Udo and Uzu (1972) for some
well-drained Nigerian soils.
Fitter AH, Sutton CD (1975) The use of the Freundlich isotherm for
soil phosphate sorption data. Klong Thom (Km) SL 2.2
3. Soil Science 59, 39-45.
Sayin M, Mermut AR, Tiessen H (1990) Phosphate sorption-desorption
characteristics by magnetically separated soil fractions. Specific surface
area (SSA) was measured using the [N.sub.2]-BET method (Aylmore et al.
1970) with a Micrometrics Gemini III 2375 surface area analyser.
Pena F, Torrent J (1990) Predicting phosphate sorption in soils of
Mediterranean regions. Fertilizer Research 23, 173-179. The organic matter content
of the soils ranged from 0.9 to 26.5 g/kg, with a median of 6.4g/kg.
Values of OM ranged from 4.1 to 26.5 g/kg (median 11.2 g/kg) for surface
soils and 0.9 to 12.2g/kg (4.9 g/kg) for subsoils. After
shaking, the soil suspensions were centrifuged and the supernatant liquid was decanted and analysed for P by the molybdate blue method
(Murphy and Riley 1962). Chok Chai (Ci) 102[degrees]19’16″ 2-4 Cassava
21. 1974; Fitter and Sutton 1975).
Karim MI, Adams WA (1984) Relationships between sesquioxides,
kaolinite, and phosphate sorption in a catena of Oxisols in Malawi. The close relationship between P sorption
and SSA for Thai soils was also observed for southern Nigerian soils
(Loganathan et al. 545-566. Particle size analysis
confirmed the field observations of texture; the soils developed on
sandstone and granite generally contained much sand, whereas those on
shale/limestone and basalt mostly had 50% clay. Field soil texture for the Thai soils ranged from sandy loam to clay.
Some soils contained a few particles 2 mm. Soil Science Society of America Journal 62, 1651-1658.
Forty-five soil samples from 22 profiles were taken from surface
and subsurface horizons of soils on sandstone, shale/limestone, granite,
and basalt, which are representative of many of the soils used for
agriculture in Thailand (Vijarnsorn 2000). Soil Science Society of America
Proceedings 33, 438-444.
Siradz SA (2000) Mineralogy and chemistry of red soils of
Indonesia. Journal of Soil Science 12, 294-306.
Lopez-Hernandez ID, Barnham CP (1974) The covariance of phosphate
sorption and other soil properties in some British and tropical soils.
Journal of Soil Science 25, 196-206.
Singh B, Gilkes RJ (1991) Phosphorus sorption in relation to soil
properties for the major soil types of south-western Australia.
Australian Journal of Soil Research 29, 603-518. Signifcant relationships of P sorption capacity values with
dithionite- and oxalateextractable Fe and Al have been reported by many
authors (Syers et al. Journal of Soil Science 26, 241-246.
Bromfield SM (1965) Studies on the relative importance of iron and
aluminum in the sorption of phosphate by some Australian soils.
Australian Journal of Soil Research 3, 31-44. Fang Danag (Fd) SC 2.0
6. (Ed. (American Society of
Agronomy: Madison, WI)
Holmgren GGS (1967) A rapid citrate-dithionite extractable iron
procedure. Some of the surface soils developed on
shale/limestone (Pc, Ak, and Ptu) and basalt (Ci) were only slightly
acid with pH(water) 6.0-6.5. Soil Science 112, 267-275.
The ratio of [Fe.sub.o]/[Fe.sub.d] has been taken as an indicator
of the maturity or crystallinity of free iron oxides in soils (Blume and
Schwertmann 1969). Hang Chat (Hc) SL 15.1
18. Maataloustietullinen Aikakaukirza 35,
W. The Freundlich b coefficient, which is an
indicator of the energy of adsorption, ranged from 0.21 to 0.66, with a
median of 0.39. Sandy soils tended to sorb
less P so that P sorption maximum values for soils developed on
sandstone (132 [micro]g/g) and granite (313 [micro]g/g) were generally
less than for shale/limestone and basalt (579 [micro]g/g). Journal of Soil Science 43, 645-567.
(D) Corresponding author. However, in this study it appears that both [Al.sub.d] and
[Al.sub.o] are superior indicators for P sorption for these soils, in
accordance with many previous studies (Bromfield 1965; Sayin et al.
1990; Singh and Gilkes 1991; Agbenin and Tiessen 1994; Siradz 2000;
Agbenin 2003). Chalong (Chl) C 5.5
16. Kohong (Kh) LS 3.2
2. 5. Soil Science 124, 370-376.
Burkitt LL, Moody PW, Gourley CJP, Hannah MC (2002) A simple
phosphorus buffering index for Australian soils. Kasetsart Journal of
Natural Science 19, 265-271.
Materials and methods
Barrow NJ, Shaw TC (1975) The slow reactions between soil and
anion. Tasae (Te) SL 2.6
5. Lawrance lowlands. Phuket (Pk) Ban Na San district, 8[degrees]42’12″
17. We have not followed this procedure in the
present research because we wanted to use the same procedures as in the
previous studies (where this modification was not made) with which we
are comparing our results.
We gratefully acknowledge the support of this work by the Royal
Golden Jubilee PhD program under the Thailand Research Fund for
financial support. Chiang Khong (Cg) CL-C 1.7
Table 2. These values are similar to those for Ultisols from
Nigeria (5 80g/kg) (Mosugu et al. Analytica Chimica Acta 27,
31-36. doi: 10.1016/00167061
Accurately weighed amounts of about 1.0 g of air-dried soil samples
(2 mm fraction) in 20 mL 0.01 M Ca[Cl.sub.2] containing K[H.sub.2]
P[O.sub.4] at various concentrations were shaken on an end-over-end
shaker at 25 [+ or -] 1[degrees]C for 17 h, and a few drops of toluene were added to suppress microbial action (Ozanne and Shaw 1967). Soil Science 37, 29-38.
Fitzpatrick RW, Schwertmann U (1982) Al-substitution goethite–an
indicator of pedogenic and other weathering environments in South
Africa. Tasae (Te) 100[degrees]30’55″ 4-5 Para rubber
5. Tha Mai (Ti) 102[degrees]2’42″ 5-8 Para rubber
19. Hang Chat (Hc) Hang Chat district, 18[degrees]19’25″
18. Chok Chai (Ci) Khonburi district, 14[degrees]31’58″
21. The highest values of DCB- and
oxalate-Al were for soils developed on basalt (median [Al.sub.d] 3.5 and
[Al.sub.o] 1.3 g/kg), followed by those on shale/limestone (median
[Al.sub.d] 2.3 and [Al.sub.o] 1.1 g/kg), granite (median [Al.sub.d] 1.4
and [Al.sub.o] 0.8 g/kg), and sandstone (median [Al.sub.d] 0.7 and
[Al.sub.o] 0.4 g/kg). Available P was
determined by the Bray II method (Bray and Kurtz 1945). 2. These values are similar to those for Ultisols and Inceptisols of the Niger delta in southern Nigeria (337 [micro]g/g) (Loganathan et
al. pp. 1971).
Agbenin JO, Tiessen H (1994) The effects of soil properties on the
differential phosphate sorption by semi-arid soils from Northeast
Brazil. MSc thesis, University of Western Australia.
Agbenin JO (2003) Extractable iron and aluminum effects on
phosphate sorption in a savanna Alfisols. Holmgren (1967) reported that DCB-extractable Al
is thought to be the Al that is substituted for [Fe.sup.3+] in
crystalline Fe oxides. logx) equations are shown in Fig. Tha Mai (Ti) C 82.0
19. Fang Danag (Fd) 99[degrees]8’12″ 5-8 Para rubber
6. 1971; Udo and Uzu 1972; Juo and Fox 1977; Jones
1981; Karim and Adams 1984; Loganathan et al. The SSA of these
soils ranged from 2 to 78 [m.sup.2]/g, with a median of 23 [m.sup.2]/g.
About 80% of the samples had SSA 40 [m.sup.2]/g (Fig. PhD thesis, University of Western
[FIGURE 3 OMITTED]
Juo AS R, Fox RL (1977) Phosphorus sorption characteristics of some
bench-mark soils of West Africa. The
highest values of SSA were for soils developed on basalt (range 28 78
[m.sup.2]/g, median 41 [m.sup.2]/g), followed by those on
shale/limestone (7-61 [m.sup.2]/g, 32 [m.sup.2]/g), granite (5-24
[m.sup.2]/g, 14 [m.sup.2]/g), and sandstone (2-30 [m.sup.2]/g, 8
The frequency distributions of DCB- and oxalate-soluble Fe and Al
values for 45 soil samples are given in Fig. Klong Chak (Kc) 102[degrees]29’12″ 5-8 Para rubber
11. Pathiu (Ptu) Pathiu district, 10[degrees]43’38″
14. Effect of time and temperature on the decrease in phosphate
concentration in the soil solution. Gilkes (C)
Blume HP, Schwertmann U (1969) Genetic evaluation of profile
distribution of Al, Fe and Mn oxides. Tasae (Te) Hadyai district, Songkla 7[degrees]6’12″
5. Sadao (Sd) 99[degrees]26’50″ 4-5 Forest plantation
4. Chalong (Chl) Ban Na San district, 8[degrees]47’18″
16. The regression
coefficient (r) for the Langmuir equation (range 0.88-0.99, median 0.99)
was mostly larger than for the Freundlich equation (0.71-0.99, median
0.96). The soils developed on basalt and
shale/limestone exhibit greater P sorption than those on granite and
Sorption of phosphate by Thai soils ranges from moderate ([x.sub.m]
= 35 [micro]g/g) to high (1111 [micro]g/g). Mae Taeng (Mt) 100[degrees]25’16″ 2-3 Mango
22. doi: 10.1071/SR9910603
Values of Langmuir P sorption maximum ([x.sub.m]) for the Thai
soils ranged from 35 to 1111 [micro]g/g, with a median of 370 [micro]g/g
(Fig. Soil Science Society of
America Journal 64, 659-670.
Natural Resources Conservation Service (1996) ‘Soil survey
laboratory methods manual.’ Soil Survey Investigation Report No.
42, version 3.0. Yasothon (Yt) Kumuang district, Buriram 15[degrees]14’33″
8. Matrix of correlation coefficients (r) for linear
relationships between P sorption parameters and some soil
properties for Thai soils
Number of samples = 44
[x.sub.m] a (mL/
Parameters ([micro]g/g) [micro]g)
[Fe.sub.d] 0.69 *** 0.38 *
[Fe.sub.o] 0.65 *** 0.47 **
[Al.sub.d] 0.88 *** 0.47 **
[Al.sub.o] 0.80 *** 0.38 *
Clay 0.69 *** 0.32 *
SSA 0.88 *** 0.46 **
pH(1 : 1 [H.sub.2]O) 0.27 0.08
pH(1 : 1 KCl) 0.27 0.05
OM 0.06 -0.14
Parameters k ([micro]g/g) b
[Fe.sub.d] 0.64 *** -0.40 *
[Fe.sub.o] 0.85 *** -0.14
[Al.sub.d] 0.89 *** -0.18
[Al.sub.o] 0.86 *** -0.00
Clay 0.60 *** -0.29
SSA 0.86 *** -0.30 *
pH(1 : 1 [H.sub.2]O) 0.21 -0.25
pH(1 : 1 KCl) 0.23 -0.22
OM -0.04 0.07
* P 0.05; ** P 0.01; *** P 0.001.
Table 3. Surin (Su) VGC 3.6
20. 4. 1989; Yoothong et al. PhD thesis, University of Western Australia.
Ballard R, Fiskell JGA (1974) Phosphorus concentration in coastal
plain forest soils. Thai Muang (Tim) Takua Tung district, 8[degrees]16’20″
15. They are also similar to values for Alfisols in the northern
Guinea savanna in Nigeria (range 103-460 [micro]g/g) (Agbenin 2003) but
are much lower than values for some other tropical soils, including
Andosols in Indonesia (4510 [micro]g/g) (Sjarif 1990), Oxisols developed
on volcanic ash in the Philippines (6944-14208 [micro]g/g) (Poudal and
West 1999), and Indonesian red soils (719-2747 [micro]g/g) (Siradz
2000). Geoderma 33, 283-296. The relatively high concentration of [Al.sub.d]
for the soils on basalt where most [Fe.sub.d] occurs may indicate that
Al substitution in iron oxides may be more abundant in these soils than
in the other soils. Much [Al.sub.d] is present in iron oxides
(Holmgren 1967) and the DCB reagent may extract Al substituting for Fe
in goethite and hematite, in addition to the amorphous and poorly
crystalline forms of Al dissolved by the other extractants (Singh and
Gilkes 1991). doi: 10.1071/SR9650031
Vijarnsorn P (2000) Land use conversions in Thailand. Klong Thom (Km) Pathiu district, Chumphon 10[degrees]45’40″
3. The Langmuir and Freundlich equations
are often used (Olsen and Watanabe 1957; Kaila 1963; Bache and Williams
1971; Pena and Torrent 1990) to fit P sorption data but may provide good
fits for only a limited range of P concentrations in solution (Syers et
al. Thai Muang (Tim) Co-SCL 211.0
15. Ao Luk (Ak) C 0.8
13. The much closer
relationships between the maximum P sorption coefficients ([x.sub.m] and
k) are due to all possible surfaces having sorbed P to reach their
maximum P capacity regardless of the energy of sorption involved.
Kaila A (1963) Dependence of the phosphate sorption capacity on the
aluminium and iron oxide in soils. doi: 10.1071/AR9670601
Yoothong K, Moncharoen L, Vijarnsorn P, Eswaran H (1997) Clay
mineralogy of Thai soils. Bivarate plots for [x.sub.m] are shown in Fig. 2). Klong Chak (Kc) Muang districe, Trad 12[degrees]17’14″
11. Values of [x.sub.m] for subsoils (range 84-1111 [micro]g/g,
median 400 [micro]g/g) were higher than for surface soils (35-909
[micro]g/g, median 256 [micro]g/g) as shown in Fig. PhD
thesis, Swedish University of Agricultural Sciences, Sweden.
x = k[c.sup.b]
Aylmore LAG, Sills ID, Quirk JP (1970) Surface area of homoionic
illite and montmorillonite clay minerals as measured by the sorption of
nitrogen and carbon dioxide. In ‘The role of phosphorus in
agriculture’. Freundlich k values for the Thai
soils were in the sequence basalt (range 218-1364 [micro]g/g, median 505
[micro]g/g) shale/limestone (72-742 [micro]g/g, 404 [micro]g/g)
granite (68-379 [micro]g/g, 168 [micro]g/g) sandstone (27-288
[micro]g/g, 100 [micro]g/g). Also thanks to Michael Smirk, University of Western
Australia, for assisting with the analyses.
McKeague JA, Brydon JE, Miles NM (1971) Differentiation of forms of
extractable iron and aluminium in soils. 1). Ao Luk (Ak) Ban Ta khun district, 8[degrees]56’57″
13. Surin (Su) 102[degrees]18’41″ 2-3 Cassava
20. 3), with no systematic
departure of data from the regression lines for any parent material.
Sample EC, Soper RL Racz GJ (1980) Reactions of phosphate
fertilizers in soils. Krabi (Kbi) Ao Luk district, Krabi 8[degrees]24″59″
9. Similarly for soils
from Nigeria, soil pH had no significant relationship with P sorption
(Loganathan et al. Email: email@example.com
Mehra OP, Jackson ML (1960) Iron oxide removal from soils and clays
by a dithionate-citrate system buffered with sodium bicarbonate. This may be due to liming, which is used
for agriculture in these areas. The highest concentrations of
amorphous Fe for Thai soils were for soils developed on basalt (range
1.5-13.8 g/kg, median 3.4 g/kg), followed by shale/limestone (0.9-6.9
g/kg, 2.2 g/kg), sandstone (0.2-1.4 g/kg, 0.7 g/kg), and granite
(0.3-2.5 g/kg, 0.6 g/kg).
Walkley A, Black IA (1934) An examination of the Degtjareff method
for determining soil organic matter and a proposed modification of the
chromic acid titration method. The
initial concentration needed ranged from 2 to 30[micro]g P/mL in order
to achieve final equilibrium concentrations ranging from 0.1 to 1.0
[micro]g P/mL in solution for each soil (5 points per soil). Suddhiprakarn (A,D), I.
Kheuruenromne (A), and R. 1998) and soils from Spain
(0.2-3.7 g/kg) (Pena and Torrent 1990). 1987) and for Ultisols and Alfisols formed from
acidic and basic rocks in West Africa (Juo and Fox 1977). Chok Chai (Ci) C 2.1
mathematical models have been proposed for describing the relationship
between the amount of P sorbed per unit of soil and the coexisting
concentration of P in solution. Pathiu (Ptu) 99[degrees]15’26″ 2-3 Durian
14. The same trend
was observed for soils from the northern Guinea savanna of Nigeria (103
[micro]g/g in surface soil and 460 [micro]g/g in subsoil) (Agbenin 2003)
and also for Swedish soils (Borling 2003). Soil
Science Society of America Journal 48, 406-409.
Murphy J, Riley JP (1962) A modified single solution method for the
determination of phosphate in natural waters. Soil Science Society of America Journal 57, 937-945.
Day DR (1965) Particle fractionation and particle-size analysis. The Langmuir coefficient,
a, is related (inversely) to the energy of P adsorption and values are
in the sequence: basalt (range 1.3-15.0 mL/[micro]g, median 5.1
mL/[micro]g) shale/ limestone (0.7-14.0 mL/[micro]g, median 4.5
mL/[micro]g) sandstone (0.5-7.3mL/[micro]g, median 3.4mL/[micro]g)
granite (0.5-13.5 mL/[micro]g, median 2.6 mL/[micro]g) (Fig. It is evident that the P sorption characteristics of Thai
soils closely resemble those of similar soils from other tropical
(C) School of Earth and Geographical Science, Faculty of Natural
and Agricultural Science, University of Western Australia, Crawley, WA
The frequency distributions for soil properties are given in Fig.
Table 1. 1999) and Indonesian red soils
(24-82g/kg) (Siradz 2000) but higher than for Western Australian soils
(median [Fe.sub.d] 6.2g/kg) (Singh 1991). 2. This is the reverse of the trend for Australian soils whose P
sorption data were described better by the Freundlich equation (Barrow
and Shaw 1975; Siradz 1985; Singh and Gilkes 1991 ; Burkitt et al.
2002). Journal of Soil Science 34, 333-341.
There were no highly significant relationships between soil
properties and Langmuir a or Freundlich b coefficients, which are
measures of P sorption energy. 1987; Pena and Torrent
1990; Singh and Gilkes 1991; Agbenin and Tiessen 1994; Siradz 2000;
Agbenin 2003; Boding 2003). PhD thesis, University of Western Australia.
The Langmuir equation has the form (Barrow 1978):
DCB- and oxalate-extractable Fe and Al were positively and quite
closely related to SSA for these soils (Fig. Relationship to soil properties. Values of Freundlich b were in the sequence granite
sandstone shale/limestone basalt, although there was
considerable overlap between values for soils on the 4 parent materials
and Clay Minerals 7, 317-327.
Bache BW, Williams EG (1971) A phosphate sorption index for soils.
Journal of Soil Science 22, 289-301.
[FIGURE 4 OMITTED]
Ozanne PG, Shaw TC (1967) Phosphate sorption by soils as a measure
of the phosphate requirement for pasture growth. Soil
Science 144, 330-338.
Syers JK, Evans TD,Williams DH, Muradocks JT (1971) Phosphate
sorption parameters of representative soils from RioGrande Do Sul,
Brazil. Sadao (Sd) Bang Sa Phan Noi district, 11[degrees]0’10″
4. c/x) and
Freundlich (logc v. Mae Taeng (Mt) C 11.5
22. Clays and Clay Minerals 18, 91-96.
[FIGURE 7 OMITTED]
Singh B, Gilkes RJ (1992) Properties of soil kaolins from
south-western Australia. Phuket (Pk) SiL 1.8
17. 6). 6).
Land suitable for agriculture comprises about 52% of the total area
of Thailand and most soils are phosphate (P) deficient (Vijarnsorn
2000). Kohong (Kh) Hadyai district, Songkla 6[degrees]45’18″
Science Society of America Proceedings 21,144-149.
Bray RA, Kurtz LT (1945) Determination of total organic and
available phosphorus in soil. It is an important process affecting the availability
of phosphate to plants and the effectiveness of P fertiliser. doi:
The term ‘phosphate sorption’ is used here to describe
any process in which P ions in solution react with atoms on the surface
of soil particles. Soil
Science Society of America Journal 63, 1258-1273.
Jones RC (1981) X-ray diffraction line profile analysis vs
phosphorus sorption by 11 Puerto Rican soils. 1980). Soil Science Society of America Proceedings 36,
Olsen SR, Watanabe FS (1957) A method to determine a phosphorus
adsorption maximum of soils as measured by the Langmuir isotherm. Soil Science Society of
America Journal 45, 828-825.
where x is the amount of phosphate sorbed per unit of soil
([micro]g/g soil), c is the phosphate concentration in equilibrium
solution ([micro]g/mL), a is a coefficient which is related to bonding
energy (mL/[micro]g), and [x.sub.m] is the sorption maximum ([micro]g/g
Stepwise regression analysis was used to obtain the most predictive
equation for maximum P sorption capacity as shown in Table 3