Free Standard AU & NZ Shipping For All Book Orders Over $80!
Register      Login
Soil Research Soil Research Society
Soil, land care and environmental research
RESEARCH ARTICLE

Coastal acid sulfate soils in the Saloum River basin, Senegal

Aïdara C. A. Lamine Fall A D , Jean-Pierre Montoroi B and Karl Stahr C
+ Author Affiliations
- Author Affiliations

A Department of Geography, University of Ziguinchor, BP 523 Ziguinchor, Senegal.

B Institute of Research for Development (IRD), UMR 242, IEES Paris, 32 Avenue Henri Varagnat, 93143 Bondy, France.

C Institute of Soil Science and Land Evaluation, University of Hohenheim, 70593 Stuttgart, Germany.

D Corresponding author. Email: chérif.fall@univ-zig.sn

Soil Research 52(7) 671-684 https://doi.org/10.1071/SR14033
Submitted: 4 February 2014  Accepted: 19 June 2014   Published: 10 October 2014

Abstract

Soils in boundary conditions of contrasting ecosystems generally show unique features. Transition often leads to changes in soil-forming processes, whereby the environment never comes to equilibrium and therefore the soil chemistry and mineralogy show different influences. Such an environment was analysed in the Saloum River basin, west-central Senegal. The objective was to identify the main pedogenic processes prevailing in this saline and acid pedoenvironment and to assess the influence of environmental factors (climate, topography, soil salinity and acidity) on local soil formation and mineral distribution. The terrace landscape is built up by a floodplain, a low terrace, which is still influenced by groundwater, and a middle terrace. The results show that soil properties are strongly influenced by hydrology, salinity and acidity in the entire toposequence: Gleyic Hyposalic and Hypersalic Solonchaks (Sulfatic) in the floodplain, Haplic Gleysols (Thionic) in the low terrace, and Endogleyic Arenosols in the middle terrace. The oxidation of pyrite followed by the redistribution of the main products (Fe2+ and SO42–) represents the major chemical process responsible for iron oxide and jarosite formation. Mineral distribution and crystallinity are linked to the landscape position, which controls the hydrological behaviour and reactions of Fe and S ions. Finally, we observed intrapedon processes such as gleysation, sulfidisation and sulfurisation, as well as interpedon processes such as salinisation, colluvio-alluviation and lateral eluviation. The combination of processes depends strongly on the landscape positions.

Additional keywords: acidity, acid sulfate soil, iron oxide, jarosite, salinity, Senegal.


References

Barbiéro L, Mohamedou AO, Roger L, Furian S, Aventurier A, Remy JC, Marlet S (2005) The origin of vertisols and their relationship to acid sulfate soils in the Senegal valley. Catena 59, 93–116.
The origin of vertisols and their relationship to acid sulfate soils in the Senegal valley.Crossref | GoogleScholarGoogle Scholar |

Bartlett R, James B (1980) Studying dried stored soil samples. Some pitfalls. Soil Science Society of America Journal 44, 721–724.
Studying dried stored soil samples. Some pitfalls.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DyaL3cXls1KksLY%3D&md5=7abf8b210bb09562c0147807b8639177CAS |

Barusseau JP, Ba M, Descamps C, Diop EHS, Giresse P, Saos JL (1995) Coastal evolution in Senegal and Mauritania at 103, 102 and 101-year scales: Natural and human records. Quaternary International 29-30, 61–73.
Coastal evolution in Senegal and Mauritania at 103, 102 and 101-year scales: Natural and human records.Crossref | GoogleScholarGoogle Scholar |

Bigham JM, Schwertmann U, Pfab G (1996) Influence of pH on mineral speciation in a bioreactor simulating acid mine drainage. Applied Geochemistry 11, 845–849.
Influence of pH on mineral speciation in a bioreactor simulating acid mine drainage.Crossref | GoogleScholarGoogle Scholar |

Bloom PR, Skyllberg UL, Sumner ME (2005) Soil acidity. In ‘Chemical processes in soils’. Book Series 8. (Eds MA Tabatabai, DL Sparks) pp. 411–459. (Soil Science Society of America: Madison, WI, USA)

Blume HP, Schwertmann U (1969) Genetic evaluation of profile distribution of aluminium, iron, and manganese oxides. Soil Science Society of America Proceedings 33, 438–444.
Genetic evaluation of profile distribution of aluminium, iron, and manganese oxides.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DyaF1MXktFGisrg%3D&md5=3a258ced0b7f27044dd1f4da1f4eb6eaCAS |

Boivin P (1991) ‘Caractérisation physique des sols sulfatés acides de la vallée de Katouré (Basse Casamance, Sénégal). Etude de la variabilité spatiale et relation avec les caractéristiques pédologiques.’ Études et Thèses. (Orstom: Paris)

Boman A, Åström M, Fröjdö S (2008) Sulfur dynamics in boreal acid sulfate soils rich in metastable ironsulfide—the role of artificial drainage. Chemical Geology 255, 68–77.
Sulfur dynamics in boreal acid sulfate soils rich in metastable ironsulfide—the role of artificial drainage.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD1cXhtVOqs7jJ&md5=b288fd3a00fee2dd7ba6fd1d80a47599CAS |

Buol SW, Hole FD, McCracken RJ (1997) ‘Soil genesis and classification.’ (Iowa State University Press: Ames, IA, USA)

Burton ED, Bush RT, Sullivan LA (2006) Sedimentary iron geochemistry in acidic waterways associated with coastal lowland acid sulfate soils. Geochimica et Cosmochimica Acta 70, 5455–5468.
Sedimentary iron geochemistry in acidic waterways associated with coastal lowland acid sulfate soils.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD28XhtFyksLvE&md5=1f28cd38e27beaaec7fd4bfe7b4289fbCAS |

Burton ED, Sullivan LA, Bush RT, Powell B (2008) Iron-sulfide and trace element behaviour in sediments of Coombabah Lake, southern Moreton Bay (Australia). Marine Pollution Bulletin 56, 1353–1358.
Iron-sulfide and trace element behaviour in sediments of Coombabah Lake, southern Moreton Bay (Australia).Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD1cXotFCku7g%3D&md5=6d0721d3762e116f9e5cc15c81cdbc01CAS | 18502448PubMed |

Bush RT, Sullivan LA, Lin C (2000) Iron monosulfide distribution in three coastal floodplain acid sulfate soils, eastern Australia. Pedosphere 10, 237–245.

Claff SR, Sullivan LA, Burton ED, Bush RT (2010) A sequential extraction procedure for acid sulfate soils: Partitioning of iron. Geoderma 155, 224–230.
A sequential extraction procedure for acid sulfate soils: Partitioning of iron.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BC3cXitlWgtbs%3D&md5=cb50ca5dcf80892f45eef674170c4fdcCAS |

Deckers J, Raes D, Merckx R, Diallo A (1993) The fate of salic and thionic fluvisols under irrigated rice in the Senegal river delta. Pédologie 43, 389–401.

Dent DL (1986) ‘Acid sulfate soils: a baseline for research and development.’ (ILRI: Wageningen, The Netherlands)

Dent DL, Ahmed F (1995) Resurrection of soil survey. A case study of acid sulfate soils on the floodplain of the River Gambia. I. Data validation, taxonomic and mapping units. Soil Use and Management 11, 69–76.

Dent DL, Pons LJ (1995) A worldperspective on acid sulfate soils. Geoderma 67, 263–276.
A worldperspective on acid sulfate soils.Crossref | GoogleScholarGoogle Scholar |

Diop S (1990) ‘La côteouestafricaine. Du Saloum (Sénégal) à la Mellacorée (Rép. de Guinée).’ Études et Thèses. (Orstom: Paris)

Dürr M, Wakelin SA, Rogers SL, White I, Macdonald BCT, Welch S (2006):Archealdiversityof an acid sulfate soil in coastal northern NSW. In ‘Regolith 2006—Consolidation and dispersion of ideas’. (Eds RW Fitzpatrick, P Shand) pp. 63–66. (CRC LEME: Bentley, W. Aust.)

Fanning DS, Burch SN (1997) Acid sulfate soils and some associated environmental problems. Advances in GeoEcology 30, 145–158.

Fanning DS, Fanning MCB (1989) ‘Soil: morphology, genesis, and classification.’ (John Wiley and Sons: New York)

Fanning DS, Rabenhorst MC, Burch SN, Islam KR, Tangren SA (2002) Sulfides and sulfates. In ‘Soil mineralogy with environmental applications’. (Eds JE Amonette, WF Bleam, DG Schulze, JB Dixon) pp. 229–256. (Soil Science Society of America, Inc.: Madison, WI, USA)

Fanning DS, Rabenhorst MC, Balduff DM, Wagner DP, Orr RS, Zurheide PK (2010) An acid sulfate perspective on landscape/seascape soil mineralogy in the U.S. Mid-Atlantic region. Geoderma 154, 457–464.
An acid sulfate perspective on landscape/seascape soil mineralogy in the U.S. Mid-Atlantic region.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD1MXhs1Wltb%2FK&md5=e884b873fa8d86de2fb6f498491a6415CAS |

Faye S, Faye SC, Ndoye S, Faye A (2003) Hydrogeochemistry of the Saloum (Senegal) superficial coastal aquifer. Environmental Geology 44, 127–136.

Fitzpatrick RW, Baker AKM, Raven M, Rogers S, Degens B, George R, Kirby J (2005) Mineralogy, biogeochemistry, hydro-pedology and risks of sediments, salt efflorescences and soils in open drains in the wheatbelt of Western Australia. In ‘Regolith 2005—Ten Years of CRC LEME’. (Ed. IC Roach) pp. 97–101. (CRC LEME: Bentley, W. Aust.)

Furian S, Mohamedou AO, Hammecker C, Maeght JL, Barbiéro L (2011) Soil cover and landscape evolution in the Senegal floodplain: a review and synthesis of processes and interactions during the late Holocene. European Journal of Soil Science 62, 902–912.
Soil cover and landscape evolution in the Senegal floodplain: a review and synthesis of processes and interactions during the late Holocene.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BC38Xmt1anug%3D%3D&md5=f3170fbb0f429e6b974bf86ae32dfb90CAS |

Habibullah AK, Greenland DJ, Brammer H (1971) Clay mineralogy of some seasonally flooded soils of East Pakistan. Soil Science 22, 179–190.
Clay mineralogy of some seasonally flooded soils of East Pakistan.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DyaE3MXltFWmu70%3D&md5=c666d269faee5c626ab6620d24194831CAS |

Husson O, Verburg PH, Phung MT, van Mensvoort MEF (2000) Spatial variability of acid sulphate soils in the Plain of Reeds, Mekong delta, Vietnam. Geoderma 97, 1–19.
Spatial variability of acid sulphate soils in the Plain of Reeds, Mekong delta, Vietnam.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD3cXktlCmtr4%3D&md5=b3340a1a996364471e37d9f7be94b4b6CAS |

Igwe CA, Zarei M, Stahr K (2005) Mineral and elemental distribution in soils formed on the River Niger floodplain, eastern Nigeria. Australian Journal of Soil Research 43, 147–158.
Mineral and elemental distribution in soils formed on the River Niger floodplain, eastern Nigeria.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD2MXivVOjur8%3D&md5=021506f5bc5c8d6c13243b4b3cb047a9CAS |

IUSS Working Group WRB (2006) ‘World Reference Base for soil resources. A framework for international classification, correlation and communication.’ World Soil Resources Reports, 103. (FAO: Rome)

Johnston SG, Slavich PG, Hirst P (2005) Changes in surface water quality after inundation of acid sulfate soils of different vegetation cover. Australian Journal of Soil Research 43, 1–12.
Changes in surface water quality after inundation of acid sulfate soils of different vegetation cover.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD2MXhtl2rsr0%3D&md5=a0436fbd9ebe0f913dd3a1fbc9bb00d4CAS |

Johnston SG, Keene AF, Bush RT, Burton ED, Sullivan LA, Isaacson L, McElnea AE, Ahern CR, Douglas Smith C, Powell B (2011) Iron geochemical zonation in a tidally inundated acid sulfate soil wetland. Chemical Geology 280, 257–270.
Iron geochemical zonation in a tidally inundated acid sulfate soil wetland.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BC3MXjtVKisw%3D%3D&md5=42acb78471abe81a0dbfee5c2e3b09b3CAS |

Jones EJP, Nadeau T-L, Voytek MA, Landa ER (2006) Role of microbial iron reduction in the dissolution of iron hydroxysulfate minerals. Journal of Geophysical Research 111, G01012
Role of microbial iron reduction in the dissolution of iron hydroxysulfate minerals.Crossref | GoogleScholarGoogle Scholar |

Kalck Y (1978) Evolution des zones de mangroves à Sénégal au Quaternaire. Etudes géologiques et géochimiques. PhD Thesis, Institut de Géologie Strasbourg, France.

Keene AF, Johnston SG, Bush R, Sullivan L, Burton L (2010) Reductive dissolution of natural jarosite in a tidally inundated acid sulfate soil: geochemical implications. In ‘19th World Congress of Soil Science, Soil Solutions for a Changing World’. 1–6 August 2010, Brisbane, Australia. (International Union of Soil Sciences)

Knight RJ, Sylva RN (1974) Precipitation in hydrolysed iron(III) solutions. Journal of Inorganic and Nuclear Chemistry 36, 591–597.
Precipitation in hydrolysed iron(III) solutions.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DyaE2cXkvFKksbc%3D&md5=3fa688b0a5f4682c235b46bc11557506CAS |

Kraal P, Burton ED, Bush RT (2013) Iron monosulfide accumulation and pyrite formation in eutrophic estuarine sediments. Geochimica et Cosmochimica Acta 122, 75–88.
Iron monosulfide accumulation and pyrite formation in eutrophic estuarine sediments.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BC3sXhs1yqsrvP&md5=475f31fb2e525a6cdbd96b457c9f4462CAS |

Lappartient JR (1985) Le continental terminal et le pléistocène ancien du bassin sénégalo-mauritanien. Stratigraphie, sédimentation, diagenèse, altérations. Reconstitution des paléorivages au travers des cuirasses. PhD Thesis, Aix-Marseille III University, Marseille, France.

Le Brusq JY, Loyer JY, Mougenot B, Carn M (1987) Nouvelles paragénèses à sulfates d’aluminium, de fer et de magnésium, et leur distribution dans les sols sulfatés acides du Sénégal. Science du Sol 25, 173–184.

Lézine A-M (1997) Evolution of the West African mangrove during the Late Quaternary: A review. Géographiephysique et Quaternaire 51, 405–414.
Evolution of the West African mangrove during the Late Quaternary: A review.Crossref | GoogleScholarGoogle Scholar |

Lin C, Melville MD (1993) Control of soil acidification by fluvial sedimentation in an estuarine floodplain, eastern Australia. Sedimentary Geology 85, 271–284.
Control of soil acidification by fluvial sedimentation in an estuarine floodplain, eastern Australia.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DyaK2cXhslaktrs%3D&md5=738db56b9d4f487ab649407087f14e32CAS |

Marius C (1985) ‘Les mangroves du Sénégal et de la Gambie.’ Travaux et Documents 193. (Orstom: Paris)

Marius C, Lucas J (1991) Holocene mangrove swamps of West Africa: sedimentology and soils. Journal of African Earth Sciences 12, 41–54.
Holocene mangrove swamps of West Africa: sedimentology and soils.Crossref | GoogleScholarGoogle Scholar |

Michel P (1973) ‘Les bassins des fleuves Senegal et Gambie: étude géomorphologique.’ Mémoires de I’Office de Recherche Scientifque et Technique d’outre-Mer (ORSTOM J 63). (Orstom: Paris)

Montoroi JP (1995) Mise en évidence d’une séquence de précipitation des sels dans les sols sulfatés acides d’une vallée aménagée de Basse-Casamance (Sénégal). Comptes Rendus de l’Académie des sciences, Paris 320, IIa, pp. 395–402. [extended abstract in English]

Montoroi J-P (1996) ‘Gestion durable des sols de la mangrove au Sénégal en période de sécheresse. Dynamique de l’eau et géochimie des sels d’un bassin versant aménagé.’ Études et Thèses. (Orstom: Paris)

Sadio S (1991) ‘Pédogénèse et potentialités forestières des sols sulfatés acides salés des tannes du Sine Saloum, Sénégal.’ (Orstom: Paris)

Schaetzl RJ, Anderson S (2005) ‘Soils: genesis and geomorphology.’ (Cambridge University Press: Cambridge, UK)

Schlichting E, Blume HP, Stahr K (1995) ‘Bodenkundliches Praktikum.’ (Blackwell Wissenschafts-Verlag: Berlin)

Schwertmann U (1966) Inhibitory effect of soil organic matter on the crystallization of amorphous ferric hydroxide. Nature 212, 645–646.
Inhibitory effect of soil organic matter on the crystallization of amorphous ferric hydroxide.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DyaF2sXitFShsw%3D%3D&md5=98391fc8d5e799bc0c332fd649efc65aCAS |

Schwertmann U, Murad E (1983) The effect of pH on the formation of goethite and hematite from ferrihydrite. Clays and Clay Minerals 31, 277–284.
The effect of pH on the formation of goethite and hematite from ferrihydrite.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DyaL3sXls1WlsLg%3D&md5=e4255e4fc0c9b9ed5acd24d6153dfa49CAS |

Schwertmann U, Fischer WR, Papendorf H (1968) The influence of organic compounds on the formation of iron oxides. In ‘Transactions 9th International Congress of Soil Science’. Adelaide, S. Aust. Vol. 1, pp. 645–655. (International Society of Soil Science and Angus and Robertson: Sydney)

Simonson RW (1978) A multiple-process model of soil genesis. In ‘Quaternary soils. 3rd Symposium on Quaternary Research’. Toronto, Canada, 21–23 May 1976. (Ed. WC Mahaney) pp. 1–25. (Geo Abstracts: Norwich, England)

Smith J, van Oploo P, Marston H, Melville MD, Macdonald BCT (2003) Spatial distribution and management of total actual acidity in an acid sulfate soil environment, McLeods Creek, northeastern NSW, Australia. Catena 51, 61–79.
Spatial distribution and management of total actual acidity in an acid sulfate soil environment, McLeods Creek, northeastern NSW, Australia.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD38XptFOjsb0%3D&md5=1a96fc9ba9c560e8dbbde12c74123067CAS |

Souza-Júnior VS, Vidal-Torrado P, Garcia-Gonzaléz MT, Otero XL, Macías F (2008) Soil mineralogy of mangrove forests from the State of São Paulo, Southeastern Brazil. Soil Science Society of America Journal 72, 848–857.
Soil mineralogy of mangrove forests from the State of São Paulo, Southeastern Brazil.Crossref | GoogleScholarGoogle Scholar |

Sullivan LA, Bush RT (1997) Quantitative elemental microanalysis of rough-surfaced soil specimens in the scanning electron microscope using a peak-to-background method. Soil Science 162, 749–757.
Quantitative elemental microanalysis of rough-surfaced soil specimens in the scanning electron microscope using a peak-to-background method.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DyaK2sXmvVyks70%3D&md5=12ea510faae2a88aa991a21618e4ebcdCAS |

Sullivan LA, Ward NJ, Bush RT, Burton ED (2009) Improved identification of sulfidic soil materials by a modified incubation method. Geoderma 149, 33–38.
Improved identification of sulfidic soil materials by a modified incubation method.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD1MXhtF2nurw%3D&md5=4795fd581e589b757f294b8c38125abcCAS |

Sylla M, Stein A, van Mensvoort MEF, van Breemen N (1996) Spatial variability of soil actual and potential acidity in the mangrove agroecosystem of West Africa. Soil Science Society of America Journal 60, 219–229.
Spatial variability of soil actual and potential acidity in the mangrove agroecosystem of West Africa.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DyaK28Xns1Srtw%3D%3D&md5=e4eb176f3c6ca65889877d5aef513dabCAS |

Torrent J, Guzmann R, Parra MA (1982) Influence of relative humidity on the crystallization of Fe(III) oxides from ferrihydrite. Clays and Clay Minerals 30, 337–340.
Influence of relative humidity on the crystallization of Fe(III) oxides from ferrihydrite.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DyaL38XltlSksr4%3D&md5=1abb862fc0eabdf11067c540498580ffCAS |

van Beers C (1962) ‘Acid sulphate soils.’ (ILRI: Wageningen, The Netherlands)

van Breemen N (1973) Soil forming processes in acid sulphate soils. In ‘Proceedings International Symposium on Acid Sulfate Soils’. 11–20 August, 1972. (Ed. H Dost) pp. 66–129. (ILRI Publication: Wageningen, The Netherlands)

van Breemen N (1975) Acidification and deacidification of coastal plain soils as a result of periodic flooding. Soil Science Society of America Proceedings 39, 1153–1157.
Acidification and deacidification of coastal plain soils as a result of periodic flooding.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DyaE28Xmt1yjtw%3D%3D&md5=b11dddb86446faa73d94767f943a003eCAS |

van Breemen N (1976) ‘Genesis and solution chemistry of acid sulfate soils in Thailand.’ Agricultural Research Report 848. (Centre for Agricultural Publishing and Documentation: Wageningen, The Netherlands)

van Breemen N (1982) Genesis, morphology and classification of acid soils in coastal plains. In ‘Acid sulfate weathering’. Special Publication 10. (Eds JA Kittrick, DS Fanning, LR Hossner) pp. 95–108. (Soil Science Society of America: Madison, WI, USA)

van Breemen N, Harmsen K (1975) Translocation of iron in acid sulfate soils: I. Soil morphology and mineralogy of iron in a chronosequence of acid sulfate soils. Soil Science Society of America Journal 39, 1140–1148.
Translocation of iron in acid sulfate soils: I. Soil morphology and mineralogy of iron in a chronosequence of acid sulfate soils.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DyaE28XlslyltA%3D%3D&md5=d3e450fd5896be2d7295805b0c884503CAS |

Vepraskas MJ, Teets SJ, Richardson JL, Tandarich JP (1995) Development of red oximorphic features in constructed wetland soils. Wetlands Research, Inc. Technical Paper No. 5, pp. 1–12.

Vieillefon J (1977) ‘Les Sols des mangroves et des tannes de Basse Casamance (Sénégal).’ Mémoires 83. (Orstom: Paris)

Willett IR, Higgins ML (1978) Phosphate sorption by reduced and reoxidized rice soils. Australian Journal of Soil Research 16, 319–326.
Phosphate sorption by reduced and reoxidized rice soils.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DyaE1MXosFOrtw%3D%3D&md5=1f37eaaf7a00672d3ae936b8e553bf32CAS |

Willett IR, Walker PH (1982) Soil morphology and distribution of iron and sulfur fraction in a coastal floodplain toposequence. Australian Journal of Soil Research 20, 283–294.
Soil morphology and distribution of iron and sulfur fraction in a coastal floodplain toposequence.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DyaL3sXhvFyntQ%3D%3D&md5=6f8f39ef5c98a76275ac2be824bd4d64CAS |

Willett IR, Muirhead WA, Higgins ML (1978) The effects of rice growing on soil phosphorus immobilization. Australian Journal of Experimental Agriculture and Animal Husbandry 18, 270–275.
The effects of rice growing on soil phosphorus immobilization.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DyaE1cXkt1aqtrk%3D&md5=0a9b9ce66c615103ccee067f4240fe28CAS |

Wright JB, Hastings DA, Jones WB, Williams HR (1985) ‘Geology and mineral resources of West Africa.’ (Springer: Dordrecht, The Netherlands)