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Optimization of a method for soil sulphur extractionE. Bloem a , S. Haneklaus a & E. Schnug aa Institute of Plant Nutrition and Soil Science , Federal Agricultural Research Centre ,Bundesallee 50, Braunschweig, D-38116, GermanyPublished online: 23 Aug 2006.

To cite this article: E. Bloem , S. Haneklaus & E. Schnug (2002) Optimization of a method for soil sulphur extraction,Communications in Soil Science and Plant Analysis, 33:1-2, 41-51, DOI: 10.1081/CSS-120002376

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OPTIMIZATION OF A METHOD FOR SOILSULPHUR EXTRACTION

E. Bloem,* S. Haneklaus, and E. Schnug

Institute of Plant Nutrition and Soil Science,

Federal Agricultural Research Centre, Bundesallee 50,

D-38116 Braunschweig, Germany

ABSTRACT

Numerous methods for the determination of soil sulphur (S) have

been developed and tested in field conditions, but so far none of

them have shown a satisfying relationship to crop yield.

Therefore, these methods are not suitable to be used to evaluate

the sulphur supply or to determine the sulphur fertilizer demand.

In this paper a successful approach was adapted and optimized for

routine analysis in soils in humid conditions. Modifications

included a comparison of soil incubation with shaking, changes in

the concentration of the extractant, the soil-to-extractant ratio, the

time of shaking, particle size of the soil and method of detection.

The best results in terms of a high reproducibility and sensitivity

of the method for soils with extremely low, but also high, sulphur

contents were obtained when the soil was extracted in a 1:5 ratio

with 0.025 M KCl, shaken for 3 hr and then filtered. The method is

suitable for ICP and IC measurement, whereby IC is preferable on

low sulphur soils because of the higher detection limit.

41

Copyright q 2002 by Marcel Dekker, Inc. www.dekker.com

*Corresponding author.

COMMUN. SOIL SCI. PLANT ANAL., 33(1&2), 41–51 (2002)

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INTRODUCTION

Several investigations have shown that the relationship between inorganic

soil sulphate (SO4) and crop yield is only weak, or indeed not evident in field

conditions (1–4). For a soil method to be reliable, there has to be a close

relationship between the available content of the soil nutrient and yield or the

nutrient content of the plant, respectively. A significant relationship was only

found in pot trials using controlled growth conditions (4–8). Missing or poor

correlations are the major reason for the great number of different methods and

ongoing research for new methods (9–13).

The methods differ in preparation of soil samples, concentration and type

of extractant, duration of the extraction procedure, the soil-to-extractant ratio, the

conditions of extraction, and the method that is used for the determination of

sulphur (S) or SO4-S in the extract (Table 1). The methods differ in the S fractions

that are extracted: most methods (Table 1) extract easily soluble plant available

Table 1. Different Extraction Parameters Used in Soil Analysis for the Determination of

Plant Available Soil Sulphur

Method/Parameter Treatment/Equipment

Preparation of soil samples † Air drying † Fine grinding

† Heating (1058C) † Fresh

Extractant † H2O † KCl

† CaCl2 † NH4Cl

† LiCl † HCl

† NH4OAc † Ca(H2PO4)2 £ H2O

† KH2PO4 † Ca(C2H3O2)2

† NaHCO3 þ Na2CO3 † K2NO3

Concentration of the extractant † 0–1 M

Duration of extraction † 15 min–24 hr

Soil-to-extractant ratio † 1:2–1:20

Conditions during extraction † Temperature † Charcoal treatment

† Alkaline treatment † Repeated percolation

† Shaking † Ion exchange

† Centrifugation † Membrane

† Filtration † Perfusion system

Method for the determination † Turbidimetric † IC

† Colorimetric † AAS

† ICP † HPLC

† CEC

References: (5,14–32).

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SO4. Soils with a high SO4 adsorption capacity are low in pH so that phosphate-

containing extractants extract more SO4 than other salt solutions because of ion-

exchange processes. Some special treatments, such as heating of the samples,

alkaline conditions or incubation studies, allow the measurement of either the

easily mineralized organic S pool or the rapidly mineralized organic S. Both

pools are determined by ICP (Inductively-coupled plasma), which captures the

total soluble S concentration (organic and inorganic).

The method developed by Blair et al. (5), referred to as the BLAIR method,

uses an incubation step of soil and extractant for 3 hr at 408C and determines both

the inorganic SO4-S and the fraction of the organic S pool that is supposed to be

plant available S.

This method provided a closer relationship ðr 2 ¼ 0:73Þ between plant

available S and yield of pasture than methods that only extracted inorganic SO4.

The disadvantage of the BLAIR method is that it is too time-consuming to be

used in routine analysis. It was the aim of this study to adapt and optimize the

BLAIR method with a view to reproducibility, sensitivity, and speed of the

analysis because it is currently the most promising approach to determine the

plant available S supply in soils. The BLAIR method was modified to be easily

measurable not only by ICP but also by IC (ion chromatography).

MATERIALS AND METHODS

Topsoil samples (0–30 cm) of an alluvial soil were collected in

Nienwohlde (5285100100N, 1083400100E, Germany). This soil was chosen because

of a high organic matter content and additionally high SO4-S contents where the

differences between IC and ICP-AES measurement were expected to be highest

and possible problems with coloring of the extracts, too. The soil was a podzol-

gleyzol with more than 80% sand in the top soil, a pH of approximately 6.0 and

organic matter content of 4.1% Corg. The soil was influenced by groundwater and

had total S content of 427 mg kg21 S in the top soil and also inorganic SO4-S

content of 4.3–24.5 mg kg21 SO4-S (measured with modified method “G”, Table

2) depending on the sampling date, with higher levels in summer and lower

values in spring (33). The crop rotation was sugar beet, winter wheat and summer

barley.

Soil samples were extracted with the BLAIR method and individual

method parameters subsequently modified to test their effect on sensitivity,

reproducibility, and time of analysis (Table 2).

Extraction procedure “A” was the original BLAIR method: 3 g of air-dry

soil plus 20 mL 0.25 M KCl were incubated for 3 hr at 408C. Then the samples

were centrifuged at 5200 £ g for 20 min, filtered (Schleicher and Schuell, No.

593), and analyzed by ICP-AES (inductively-coupled plasma atomic emission

SOIL SULPHUR EXTRACTION 43

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spectrometry). The measurement with ICP-AES was favored by Blair et al. (5)

because of the ability to determine not only inorganic SO4-S, but also a small but

relevant fraction of the plants’ available S organic compounds. In this

investigation ICP-AES (Perkin–Elmer) and IC (Dionex-Quick System with pre-

column AG4A, measurement column AS4A and a mixture of 1.7 mM NaHCO3

and 1.8 mM Na2CO3 as effluent) were used for the final determination of total

soluble S and SO4-S. The original extracts of the BLAIR method could not be

used for IC analysis because of the high salt concentration of the extracts that

interfered with the measurement. Therefore procedures “B–F” (Table 2) were

tested for further improvement of the method and optimized steps were

amalgamated in procedure “G”. In procedure “G” (Table 2), the method was

modified in such a way that SO4-S could be determined by IC or ICP with high

accuracy: 10 g air dry and sieved (,2 mm) soil was shaken with 50 mL 0.025 M

KCl for 3 hr on a horizontal shaker. The samples were filtered (Schleicher and

Schuell, No. 593) and the extracts ready for measurement with ICP-AES or IC.

All treatments were extracted and analyzed in five-fold repetition.

The SPSS software package (34) was used for statistical analysis.

RESULTS AND DISCUSSION

Different methods for extraction of SO4 provided different results because

of the strong influence of soil characteristics (35). Therefore, it was necessary to

assess the suitability of methods for different sites. In this study, the BLAIR

method was tested because of its close relationship to crop yield (5); however, no

relationship was found in humid conditions, and low SO4-S values in S deficient

soils were below the detection limit of ICP-AES (33). Therefore, the BLAIR

method was modified to get a fast and accurate method that enables use of IC

instead of ICP-AES for lower detection limits.

The chosen soil material was high in plant available SO4-S and organic

matter. High organic matter content is problematic because of extract coloring

that influences the measurement; therefore, it was important to prevent a coloring

of the extracts. On the other hand, with high organic matter content, differences

between IC or ICP-AES measurement were expected to be highest, because the

amount of plant available organic S has to be higher in organic matter rich soils,

too. Additionally with high SO4-S content, differences in the SO4 extraction force

between the methods are more distinct.

The practical detection limit (36) of S determined by ICP-AES proved to

be 0.5 mg L21 S corresponding to 3.3 mg kg21 S (3:20 extract) in the soil. On S

deficient sites, SO4-S of only 2 mg kg21 S was measured in the top soil (33) so

that the original BLAIR method was not suitable for low SO4-S soils because

the SO4-S content of the soils were regularly below the detection limit of the

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ICP-AES. IC was much more sensitive with a practical detection limit of

0.1 mg L21 SO4-S (corresponding to 0.67 mg kg21 S in a 3:20 extract), allowing

SO4-S to be determined in low in SO4 soils. In northern Europe, more and more

soils are becoming S deficient, e.g., Refs. (37,38,39), because of low S input and

high mobility of SO4, which causes high losses during winter due to leaching.

On S deficient soils IC would be the favorable method of determination and

modifications of the BLAIR method were adapted preferably for IC.

Figure 1 summarizes the results of S and SO4-S determinations of the

modified methods (Table 2). Samples extracted with 0.25 M KCl (A, B, D–F)

showed a distinctly higher SO4-S level than samples extracted with 0.025 M KCl

(C þ G). The reproducibility of the results in the 0.25 M KCl extract was reduced

because of an unsatisfactory peak separation. So, all samples were diluted (1:1)

and measured again by IC. The SO4-S level of the diluted samples corresponded

with those determined in 0.025 M KCl.

Higher SO4-S levels in 0.25 M KCl extracts could be traced back to the

chloride peak, which could not be clearly separated from the SO4 peak (Fig. 2)

Figure 1. Influence of different modifications of the BLAIR method on the amount of

extracted SO4-S or soluble S and standard deviation of the measurements ðn ¼ 5Þ:

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resulting in over-estimated SO4-S values. Therefore using IC, only extractants

with a low chloride content should be used. The investigations further revealed

that the concentration of the extractant could be reduced to 0.025 M KCl without

influencing the amount of SO4-S extracted but with the advantage of a clear peak

separation and improved reproducibility of the method (Figs. 1 and 2).

The difference between results obtained by IC (diluted samples) and ICP-

AES (undiluted samples) was only minor and not significant (Fig. 1). This finding

shows that the soil contained nearly no available S from the organic S pool

despite its high organic matter content. The lowest standard deviation of

measurements was determined for method “G”.

Differences in extracted S determined by ICP-AES depending on the

concentration of the extractant and temperature during extraction was not

significant (F-test p . 0.05). Other parameters such as particle size, the soil-to-

extractant ratio, and shaking, however, had a significant influence on the amount

of extracted S. A wider soil-to-extractant ratio of 1:5 resulted in a lower

extraction force. In the different analytical methods described in literature (Table

1), the soil-to-extractant ratio ranged from 1:2 (18) to 1:20 (31). For soils with

low SO4-S, it is important that the chosen ratio extracts S in amounts exceeding

the practical detection limit of the method used (see above). This criterion was

achieved with a soil-to-extractant ratio of 1:5 (“D” in Fig. 1). A soil-to-extractant

ratio of 1:5 is also the most frequently used ratio in soil analysis (10).

Fine grinding of soil material (“F” in Fig. 1) did significantly increase the

extraction force, but yielded higher variation. Practically, fine grinding means an

extra time-consuming sample preparation step for little gain in precision.

Figure 2. Differences in the peak separation with ion chromatography in dependence on

the concentration of the extractant KCl.

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Shaking (“E” in Fig. 1), instead of incubating the samples at 408C for 3 hr

resulted in higher extractable SO4-S but also higher variation. The combination

of a wider soil-to-extractant ratio of 1:5 together with shaking for 3 hr yielded

results that were comparable to the original BLAIR method (Fig. 1). Method “G”

(Shaking 10 g soil with 50 mL 0.025 M KCl for 3 hr at room temperature before

filtration of the samples) combined all parameter modifications, and proved to be

the best method from an analytical point of view. Method “G” is an optimized,

easy and fast extraction procedure, whereby the extractants can be accurately

measured, either by ICP or IC. This method has the advantage that it may be

applied on soils with low or high SO4-S. Only on soils with a high adsorption

capacity, which are usually low in pH such as forest sites, are phosphate

containing extractants like Ca(H2PO4)2 favorable (18,40,41) because of the

extraction of adsorbed plant available SO4-S.

On agricultural soils, adsorbed SO4-S is of minor relevance because the pH

ranges usually between 6 and 8 so that adsorption of sulphate is negligible

(40,42,43), and a phosphate containing extractant would not extract higher

amounts of SO4-S.

The original BLAIR method and the modified procedure “G” (Fig. 1)

delivered no significant relationship between the SO4-S content of the soil and S

concentration in plants in humid conditions (44). The reason is to be seen in the

generally high temporal and spatial variability of the soil SO4 which follows the

water movement within soils with no relevant SO4 adsorption (44). Nevertheless

with the modified BLAIR method, a method is available which is fast, highly

accurate, and has a high accuracy to get a reliable value for the transient SO4-S

concentration of the soil.

CONCLUSIONS

The BLAIR method for SO4 extraction provided a closer and significant

relationship between extractable S and yield in a semi-arid region than other

procedures (5), but no relationship was found in humid conditions (33). The SO4

levels of S deficient soils were below the detection limit of ICP-AES. Therefore

the BLAIR method was modified to obtain a fast and accurate method enabling

the use of IC instead of ICP-AES for the measurement of low SO4-S in soils. The

optimized modified extraction method “G” presented in this paper proved to be a

fast and precise method for SO4 extraction of agricultural soils. The advantages of

the modified method “G” compared to the original BLAIR method are the

reduced time needed for analysis, the general suitability for ICP and IC, the higher

accuracy, and the distinctly lower detection limit of only 0.7 mg kg21 SO4-S when

using IC. Therefore the modified extraction method “G” together with IC

measurement is preferable on soils in humid areas with both low and high in SO4.

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REFERENCES

1. Freney, J.R.; Spencer, K. Diagnosis of Sulphur Deficiency in Plants by Soil

and Plant Analysis. J. Austr. Inst. Agric. Sci. 1967, 33, 284–288.

2. Haneklaus, S.; Fleckenstein, J.; Schnug, E. Comparative Studies of Plant

and Soil Analysis for the Sulphur Status of Oilseed Rape and Winter Wheat.

Z. Pflanzenernaehr. Bodenkd. 1995, 158, 109–111.

3. Mitchell, C.C.; Mullins, G.L. Sources, Rates and Time of Sulfur

Application to Wheat. Sulphur Agric. 1990, 14, 20–24.

4. Schnug, E. Quantitative und Qualitative Aspekte der Diagnose und

Therapie der Schwefelversorgung von Raps (Brassica napus L.) Unter

Besonderer Berucksichtigung Glucosinolatarmer Sorten. Habilitation;

Christian-Albrechts-Universitat: Kiel, Germany, 1988.

5. Blair, G.J.; Chinoim, N.; Lefroy, R.D.B.; Anderson, G.C.; Crocker, G.J. A

Soil Sulfur Test for Pastures and Crops. Aust. J. Soil Res. 1991, 29,

619–626.

6. Sanford, J.O.; Lancaster, J.D. Biological and Chemical Evaluation of the

Readily Available Sulfur Status of Mississippi Soils. Soil Sci. Soc. Proc.

1962, 26, 63–65.

7. Westermann, D.T. Indexes of Sulfur Deficiency in Alfalfa. I. Extractable

Soil SO4-S. Agron. J. 1974, 66, 578–580.

8. Yli-Halla, M. Assessment of Extraction and Analytical Methods in

Estimating the Amount of Plant Available Sulfur in Soils. Acta Agric.

Scand. 1987, 37, 419–425.

9. Alewell, C.; Matzner, E. Water NaHCO3-, NaH2PO4- and NaCl-extractable

SO224 in Acid Forest Soils. Z. Pflanzenernaehr. Bodenk. 1996, 159,

235–240.

10. Anderson, G.; Lefroy, R.; Chinoim, N.; Blair, G. Soil Sulphur Testing.

Sulphur in Agric. 1992, 16, 6–14.

11. Eriksen, J.; Murphy, M.; Schnug, E. The Soil Sulphur Cycle. In Sulphur in

Agroecosystems; Schnug, E., Ed.; Kluwer Academic Publishers: Dordrecht,

Netherlands, 1998; Vol. 2, 39–73.

12. Schnug, E.; Haneklaus, S. Diagnosis of Sulphur Nutrition. In Sulphur in

Agroecosystems; Schnug, E. Ed.; Kluwer Academic Publishers: Dordrecht,

Netherlands, 1998; Vol. 2, 1–38.

13. Warman, P.R.; Sampson, H.G. Evaluation of Soil Sulfate Extractants and

Methods of Analysis for Plant Available Sulfur. Commun. Soil Sci. Plant

Anal. 1992, 23, 793–803.

14. Alewell, C. Effects of Organic Sulfur Compounds on Extraction and

Determination of Inorganic Sulfate. Plant Soil 1993, 149, 141–144.

SOIL SULPHUR EXTRACTION 49

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ded

by [

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r U

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] at

06:

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ORDER REPRINTS

15. Autrey, R.A.; Fitzgerald, J.W. Relationship Between Microbial Activity,

Biomass and Organosulfur Formation in Forest Soil. Soil Biol. Biochem.

1993, 25, 33–39.

16. Banerjee, M.R.; Chapman, S.J.; Sinclair, A.M.; Kilham, K. Evaluation of a

Perfusion System for Investigation of the Sulphur Supplying Capacity of

Soils. Commun. Soil Sci. Plant Anal. 1994, 25, 2613–2625.

17. Barrow, N.J. Studies on Mineralization of Sulphur from Soil Organic

Matter. Aust. J. Agric. Res. 1961, 12, 306–319.

18. Camberato, J.J.; Kamprath, E.J. Solubility of Adsorbed Sulphate in Coastal

Plain Soils. Soil Sci. 1986, 142 (4), 211–213.

19. Chesnin, L.; Yien, C.H. Turbidimetric Determination of Available Sulfates.

Soil Sci. Soc. Am. Proc. 1950, 18, 149–151.

20. Fleckenstein, J., Paulsen, H.M., Bloem, E., Boreczek, B., Schnug,

E. Kapillarionenelektrophorese mit Leitfahigkeitsdetektion zur Analyse

von Anionen in Bodeneluaten; VDLUFA-Schriftenreihe, Kongrebband,

1996, 325–328.

21. Fox, R.L.; Atesalph, H.M.; Kampbell, D.H.; Rhoades, H.F. Factors

Influencing the Availability of Sulfur Fertilizers to Alfalfa and Corn. Soil

Sci. Soc. Am. Proc. 1964, 28, 406–408.

22. Freney, J.R. Determination of Water-soluble Sulfate in Soils. Soil Sci.

1958, 86, 241–244.

23. Hoeft, R.G.; Walsh, L.M.; Keeney, D.R. Evaluation of Various Extractants

for Available Soil Sulfur. Soil Sci. Soc. Am. Proc. 1973, 37, 401–405.

24. Hue, N.V.; Adams, F. Indirect Determination of Micrograms of Sulfate by

Barium Absorption Spectroscopy. Commun. Soil Sci. Plant Anal. 1979, 10,

841–851.

25. Johnson, C.M.; Nishita, H. Microestimation of Sulfur in Plant Materials,

Soils and Irrigation Waters. Anal. Chem. 1952, 24, 736–742.

26. Maynard, D.G.; Kalra, Y.P.; Radford, F.G. Extraction Determination of

Sulfur in Organic Horizons of Forest Soils. Soil Sci. Soc. Am. J. 1987, 51,

801–805.

27. Meiwes, K.J. Der Schwefelhaushalt Eines Buchenwald-und Eines

Fichtenwaldokosystems im Solling. Gottinger Bodenkundl. Ber. 1979,

60, 1–108.

28. Novozamsky, I.; van Eck, R.; van der Lee, J.J.; Houba, V.J.G.;

Tenminghoff, E. Determination of Total Sulfur and Extractable Sulphate

in Plant Materials by Inductively-Coupled Plasma Atomic Emission

Spectrometry. Commun. Soil Sci. Plant Anal. 1986, 17, 1147–1157.

29. Probert, M.E. Studies on Available and Isotopically Exchangeable Sulphur

in Some North Queensland Soils. Plant Soil 1976, 45, 461–475.

BLOEM, HANEKLAUS, AND SCHNUG50

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06:

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ORDER REPRINTS

30. Searle, P.L. The Extraction of Sulphate and Mineralisable Sulphur from

Soil with an Anion Exchange Membrane. Commun. Soil Sci. Plant Anal.

1992, 23, 2087–2095.

31. Shanley, J.B. Sulfate Retention and Release in Soils at Panola Mountain.

Georgia. Soil Sci. 1992, 153, 499–508.

32. Tan, Z.; McLaren, R.G.; Cameron, K.C. Forms of Sulfur Extracted from

Soils After Different Methods of Sample Preparation. Aust. J. Soil Res.

1994, 32, 823–834.

33. Bloem, E. Schwefel-Bilanz von Agraroekosystemen Unter Besonderer

Beruecksichtigung Hydrologischer und Bodenphysikalischer Standortei-

genschaften; Landbauforschung Voelkenrode, Sonderheft 192: Braunsch-

weig, 1998, 156 pp.

34. Pfeifer, A. Statistik-Auswertung mit SPSSx und BMDP; Gustav Fischer

Verlag: Stuttgart, Germany, 1988.

35. Gowrisankar, D.; Shukla, L.M. Evaluation of Extractants for Predicting

Availability of Sulphur to Mustard in Inceptisols. Commun. Soil Sci. Plant

Anal. 1999, 30, 2643–2654.

36. Gottwald, W. Statistik fuer Anwender; Wiley-VCH: Weinheim, Germany,

2000.

37. Booth, E.; Walker, K.C.; Schnug, E. The Effect of Site, Foliar Sulfur and

Nitrogen Application on Glucosinolate Content and Yield of Oilseed Rape.

Proc. Int. Rapeseed Cong., Saskatoon 1991, 2, 567–572.

38. Kjellquist, T.; Gruvaeus, I. Sulphur Deficiency in Oilseed Rape and

Cereals: Experience from Swedish field trials. Z. Pflanzenernaehr.

Bodenkd. 1995, 158, 101–103.

39. Knudsen, L.; Pedersen, C.A. Sulfur Fertilization in Danish Agriculture.

Sulphur in Agric. 1993, 17, 29–31.

40. Curtin, D.; Syers, J.K. Extractability and Adsorption of Sulphate in Soils.

J. Soil Sci. 1990, 41, 305–312.

41. Kang, B.T.; Okoro, E.; Acquaye, D.; Osiname, O.A. Sulfur Status of Some

Nigerian Soils from the Savanna and Forest Zones. Soil Sci. 1981, 132,

220–227.

42. Ajwa, H.A.; Tabatabai, M.A. Metal-Induced Sulfate Adsorption by Soils.

I. Effect of pH and Ionic Strength. Soil Sci. 1995, 159, 32–42.

43. Zhang, G.Y.; Brummer, G.M.; Zhang, X.N. Effect of Perchlorate, Nitrate,

Chloride and pH on Sulfate Adsorption by Variable-Charge Soils.

Geoderma 1996, 73, 217–229.

44. Bloem, E.; Haneklaus, S.; Sparovek, G.; Schnug, E. Spatial and Temporal

Variability of Sulphate Concentration in Soils. Commun. Soil Sci. Plant

Anal. 2001, 32 (9–10), 1391–1403.

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