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Soil, land care and environmental research
RESEARCH ARTICLE

Long-term application of olive-mill wastewater affects soil chemical and microbial properties

V. Kavvadias A B , M. Doula A , M. Papadopoulou A and Sid. Theocharopoulos A
+ Author Affiliations
- Author Affiliations

A Department of Soil Science of Athens, Hellenic Agricultural Organisation – Demeter, Sofokli Venizelou Str. 1, 14 123, Likovrisi, Greece.

B Corresponding author. Email: vkavvadias.kal@nagref.gr

Soil Research 53(4) 461-473 https://doi.org/10.1071/SR13325
Submitted: 8 November 2013  Accepted: 2 February 2015   Published: 10 June 2015

Abstract

Disposal of untreated olive-mill wastewater (OMW) is a major environmental problem in many Mediterranean countries. This study assessed the impact of OMW application on soil microbiological properties and explored the relationship to soil chemical properties during a 9-month, periodical soil-sampling campaign in a pilot study area in Crete, South Greece. Cases studied involved: direct application of OMW on soil; OMW disposal in active evaporation ponds; sites hosting evaporation ponds that have been inactive for the past 9 years; sites downstream of active evaporation ponds; and control soils, upstream of the waste-disposal ponds. Long-term OMW disposal on land affected the main soil chemical properties. Applicability of the results from the systematic monitoring was confirmed by results obtained in other OMW disposal sites around the pilot area. Soil microbial properties (microbial activity, microbial biomass carbon, and metabolic quotient) were considerably affected by OMW disposal. Moreover, seasonal changes of soil properties revealed short- and long-term residual effects due to OMW disposal. Significant correlations were observed among soil microbial characteristics and soil chemical properties, clearly indicating a close relationship between chemical properties and the transformation of microbial communities in soil after OMW land spreading. The determination of a key set of chemical and microbiological parameters that can be used as indicators for monitoring soil quality at olive-mill waste-disposal areas will verify the efficiency of the techniques used for the land disposal of OMW and will consequently promote their sustainable management.


References

Abdel-Sabour MF (1991) Nickel accumulation parameters, coefficients of transfer, tolerance index, and nutrient uptake by red clover grown on nickel polluted soil. The International Journal of Environmental Studies 37, 25–34.
Nickel accumulation parameters, coefficients of transfer, tolerance index, and nutrient uptake by red clover grown on nickel polluted soil.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DyaK3MXit1Oqtrs%3D&md5=885971beda70dedfadac93cbbacfff87CAS |

Alloway BJ (1995) ‘Heavy metals in soils.’ (Blackie Academic Professional: London)

Anderson TH, Domsch KH (1989) Ratios of microbial biomass carbon to total organic carbon in arable soils. Soil Biology & Biochemistry 21, 471–479.
Ratios of microbial biomass carbon to total organic carbon in arable soils.Crossref | GoogleScholarGoogle Scholar |

Anderson TH, Domsch KH (1990) Application of ecophysiological quotients qCO2 and qD on microbial biomass from soils of different cropping histories. Soil Biology & Biochemistry 22, 251–255.
Application of ecophysiological quotients qCO2 and qD on microbial biomass from soils of different cropping histories.Crossref | GoogleScholarGoogle Scholar |

Aqeel AM, Hameed KM, Alaudatt M (2007) Effect of olive mill by-products on mineral status, growth and productivity of faba bean. Journal of Agronomy 6, 403–408.
Effect of olive mill by-products on mineral status, growth and productivity of faba bean.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD1cXpslCrtw%3D%3D&md5=e93165b67c8bacfa82328c91c743d4a9CAS |

Arunachalam A, Arunachalam K (2000) Influence of gap size and soil properties on microbial biomass in a subtropical humid forest of north-east India. Plant and Soil 223, 185–193.
Influence of gap size and soil properties on microbial biomass in a subtropical humid forest of north-east India.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD3cXnt1ymsrc%3D&md5=5fdbdfeb415a865587c87ea9d655443fCAS |

Benbi K, Brara SPS (1992) Dependence of DTPA-extractable Zn, Fe, Mn, and Cu availability on organic carbon presence in arid and semiarid soils of Punjab. Arid Soil Research and Rehabilitation 6, 207–216.
Dependence of DTPA-extractable Zn, Fe, Mn, and Cu availability on organic carbon presence in arid and semiarid soils of Punjab.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DyaK3sXht1emur0%3D&md5=d8cb078a9d5401a8c089d973657fdc12CAS |

Benitez E, Melgar R, Nogales R (2004) Estimating soil resilience to a toxic organic waste by measuring enzyme activities. Soil Biology & Biochemistry 36, 1615–1623.
Estimating soil resilience to a toxic organic waste by measuring enzyme activities.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD2cXnslKht7w%3D&md5=dc9526934db9d96c5074b4200f15fe6fCAS |

Biasioli M, Barberis R, Ajmone-Marsan F (2006) The influence of a large city on some soil properties and metal content. The Science of the Total Environment 356, 154–164.
The influence of a large city on some soil properties and metal content.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD28Xhs1yqtLc%3D&md5=55979053942a927bcbdb12ef76a7536aCAS | 15941578PubMed |

Bonifacio E, Falsone G, Piazza S (2010) Linking Ni and Cr concentrations to soil mineralogy: does it help to assess metal contamination when the natural background is high? Journal of Soils and Sediments 10, 1475–1486.
Linking Ni and Cr concentrations to soil mineralogy: does it help to assess metal contamination when the natural background is high?Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BC3cXhsVCktLjL&md5=282652e0e2d7d58373ee5b1a5286f81cCAS |

Box JD (1983) Investigation of the Folin–Ciocalteu phenol reagent for the determination of polyphenolic substances in natural waters. Water Research 17, 511–525.
Investigation of the Folin–Ciocalteu phenol reagent for the determination of polyphenolic substances in natural waters.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DyaL3sXitVCjtLs%3D&md5=e29ac4cd08bf4d18270f967d513fa2feCAS |

Capasso R, Evidenti A, Schivo L, Orru G, Marcialis MA, Cristinzio G (1995) Antibacterial polyphenols from olive oil mill waste waters. The Journal of Applied Bacteriology 79, 393–398.
Antibacterial polyphenols from olive oil mill waste waters.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DyaK2MXps1Cjt7Y%3D&md5=46cc65ede31c4ac4c17662e0a773dfaeCAS | 7592132PubMed |

Castaldi P, Garau G, Melis P (2004) Influence of compost from sea weeds on heavy metal dynamics in the soil–plant system. Fresenius Environmental Bulletin 13, 1322–1328.

Clesceri LS, Greenberg AE, Eaton AD (1998) ‘Standard methods for the examination of water and wastewater.’ 20th edn (APHA, AWWA, WEF: Washington, DC)

Di Bene C, Pellegrino E, Debolini M, Silvestri N, Bonari E (2013) Short- and long-term effects of olive mill wastewater land spreading on soil chemical and biological properties. Soil Biology & Biochemistry 56, 21–30.
Short- and long-term effects of olive mill wastewater land spreading on soil chemical and biological properties.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BC38XhslymtrrP&md5=59eef05a693eb439e524e1c8224cc136CAS |

Di Serio MG, Lanza B, Mucciarella MR, Russi F, Iannucci E, Marfisi P, Madeo A (2008) Effects of olive mill wastewater spreading on the physico-chemical and microbiological characteristics of soil. International Biodeterioration & Biodegradation 62, 403–407.
Effects of olive mill wastewater spreading on the physico-chemical and microbiological characteristics of soil.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD1cXht1eisbfE&md5=57814e2e6f3ec3ff6375ea27fd863e48CAS |

Doula MK, Kavvadias V, Elaiopoulos K (2013) Proposed soil indicators for olive mill waste (OMW) disposal areas. Water, Air, and Soil Pollution 224, 1621
Proposed soil indicators for olive mill waste (OMW) disposal areas.Crossref | GoogleScholarGoogle Scholar |

Economou-Eliopoulos M, Antivachi D, Vasilatos CH, Megremi I (2012) Evaluation of the Cr (VI) and other toxic element contamination and their potential sources: The case of the Thiva basin (Greece). Geoscience Frontiers 3, 523–539.
Evaluation of the Cr (VI) and other toxic element contamination and their potential sources: The case of the Thiva basin (Greece).Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BC38Xht1aqsr3J&md5=af200062ee9eb0a65488ea51028f6c8dCAS |

Environmental Protection Agency (1995) Method 3052, SW-846: Test methods for evaluating solid waste. In ‘Vol. IA: Laboratory manual physical/chemical methods, SW 846’. 3rd edn (U.S. Government Printing Office: Washington, DC)

Environmental Protection Agency (1997) ‘Method 3051a: Microwave assisted acid digestion of sediments, sludges, soils, and oils.’ 2nd edn (U.S. Government Printing Office: Washington, DC)

Gamba C, Piovanelli C, Papini R, Pezzarossa B, Ceccarini L, Bonari E (2005) Soil microbial characteristics and mineral nitrogen availability as affected by olive oil waste water applied to cultivated soil. Communications in Soil Science and Plant Analysis 36, 937–950.
Soil microbial characteristics and mineral nitrogen availability as affected by olive oil waste water applied to cultivated soil.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD2MXkslOgtrg%3D&md5=d228b87b015e476c52a167211115cb90CAS |

Giusquiani PL, Concezzi L, Businelli M, Macchioni A (1998) Fate of pig sludge liquid fraction in calcareous soil: Agricultural and environmental implications. Journal of Environmental Quality 27, 364–371.
Fate of pig sludge liquid fraction in calcareous soil: Agricultural and environmental implications.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DyaK1cXitFGgt74%3D&md5=d5b0a4d21ee7a81877be59983f69e817CAS |

Hamarashid NH, Othman MA, Hussain MH (2010) Effects of soil texture on chemical compositions, microbial populations and carbon mineralization in soil. Egyptian Journal of Experimental Biology (Bot.) 6, 59–64.

Hanchai S, Iwai CB, Topark-Ngarm B, Homchurn S, Buterng P (2010) Soil biota activities in the salt-affected area in northeast Thailand. International Journal of Environmental and Rural Development 1–2, 54–57.

Hanifi S, El Hadrami I (2009) Olive mill wastewaters: Diversity of the fatal product in olive oil industry and its valorisation as agronomical amendment of poor soils: a review. Journal of Agronomy 8, 1–13.
Olive mill wastewaters: Diversity of the fatal product in olive oil industry and its valorisation as agronomical amendment of poor soils: a review.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD1MXmt1GltLc%3D&md5=00ca36e2ef3296b7dea31be08a133234CAS |

Harter RD, Naidu R (1995) Role of organic-metal complexation in metal sorption by soils. Advances in Agronomy 55, 219–263.
Role of organic-metal complexation in metal sorption by soils.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DyaK28XktlaqsA%3D%3D&md5=a99b24a82a002dde018d4668768df577CAS |

Heckrath G, Brookes PC, Poulton PR, Goulding KWT (1995) Phosphorus leaching from soils containing different phosphorus concentrations in the Broadbalk experiment. Journal of Environmental Quality 24, 904–910.
Phosphorus leaching from soils containing different phosphorus concentrations in the Broadbalk experiment.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DyaK2MXot1Wks7k%3D&md5=241d26e9376fd8b0a3c23736dd3940c0CAS |

ILACO B.V. (1985) ‘Agricultural compendium, for rural development in the tropics and subtropics.’ International Land Development Consultants, Arnhem, The Netherlands; commissioned by the Ministry of Agriculture and Fisheries, The Hague, The Netherlands. (Elsevier Scientific Publishing Co.: Amsterdam)

ISO (1995) ‘11261: Soil quality. Determination of total nitrogen—Modified Kjeldahl method.’ (International Organization for Standardization: Geneva)

ISO (1998) ‘14235: Soil quality. Determination of organic carbon by sulfochromic oxidation.’ (International Organization for Standardization: Geneva)

ISO (2001) ‘14870: Soil quality. Extraction of trace elements by buffered DTPA solution.’ (International Organization for Standardization: Geneva)

Kapellakis IE, Tsagarakis KP, Crowther JC (2008) Olive oil history, production and by-product management. Environmental Science and Biotechnology 7, 1–26.
Olive oil history, production and by-product management.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD1cXitFKjsbk%3D&md5=7b753a14d24d0f50fdb3b91037b2f0c2CAS |

Kaplan M (1999) Accumulation of copper in soils and leaves of tomato plants in greenhouses in Turkey. Journal of Plant Nutrition 22, 237–244.
Accumulation of copper in soils and leaves of tomato plants in greenhouses in Turkey.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DyaK1MXhtlGit74%3D&md5=4f560ff3f67c8f6adc3c013a0203f89aCAS |

Kavvadias V, Doula MK, Komnitsas K, Liakopoulou N (2010) Disposal of olive oil mill wastes in evaporation ponds: Effects on soil properties. Journal of Hazardous Materials 182, 144–155.
Disposal of olive oil mill wastes in evaporation ponds: Effects on soil properties.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BC3cXhtVajtLnK&md5=d7d57324e2f9e18c9a99f7c97419b7a1CAS | 20580156PubMed |

Kavvadias V, Komnitsas K, Doula M (2011) Long term effects of olive mill wastes disposal on soil fertility and productivity. In ‘Hazardous materials: types, risks and control’. (Ed. SK Brar) pp. 433–471. (Nova Science Publishers, Inc.: Hauppauge, NY, USA)

Kavvadias V, Doula M, Theocharopoulos S (2014) Long-term effects on soil of the disposal of olive mill waste waters (OMW). Environmental Forensics 15, 37–51.
Long-term effects on soil of the disposal of olive mill waste waters (OMW).Crossref | GoogleScholarGoogle Scholar |

Komnitsas K, Zaharaki D, Doula M, Kavvadias V (2011) Origin of recalcitrant heavy metals present inolive mill wastewater evaporation ponds and nearby agricultural soils. Environmental Forensics 12, 319–326.
Origin of recalcitrant heavy metals present inolive mill wastewater evaporation ponds and nearby agricultural soils.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BC38XhtVCmsLg%3D&md5=24610e036e326b73ed6f596adf77d409CAS |

Kotsou M, Mari I, Lasaridi K, Chatzipavlidis I, Balis C, Kyriacou A (2004) The effect of olive oil mill wastewater (OMW) on soil microbial communities and suppressiveness against Rhizoctonia solani. Applied Soil Ecology 26, 113–121.
The effect of olive oil mill wastewater (OMW) on soil microbial communities and suppressiveness against Rhizoctonia solani.Crossref | GoogleScholarGoogle Scholar |

Linzon SN (1978) ‘Phytotoxicology: Excessive levels for contaminants in soil and vegetation.’ (Ministry of the Environment: Toronto, ON, Canada)

Lozano-García B, Parras-Alcántara L, del Toro Carrillo de Albornoz M (2011) Effects of oil mill wastes on surface soil properties, runoff and soil losses in traditional olive groves in southern Spain. Catena 85, 187–193.
Effects of oil mill wastes on surface soil properties, runoff and soil losses in traditional olive groves in southern Spain.Crossref | GoogleScholarGoogle Scholar |

Madrid L, Diaz-Barrientos E (1998) Release of metals from homogeneous soil columns by wastewater from an agricultural industry. Environmental Pollution 101, 43–48.
Release of metals from homogeneous soil columns by wastewater from an agricultural industry.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DyaK1cXmtFOqsL0%3D&md5=15d13296d87fbfacdbe54ca142c5ab3fCAS | 15093097PubMed |

MAFF (1988) ‘Fertilizer recommendations.’ Reference Book 209. (HMSO: London)

Margesin R, Zimmerbauer A, Schinner F (2000) Monitoring of bioremediation by soil biological activities. Chemosphere 40, 339–346.
Monitoring of bioremediation by soil biological activities.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD3cXkt1Oktw%3D%3D&md5=64c7b80c6913ecf8596ffb3ebcf69c06CAS | 10665397PubMed |

Marx ES, Hart J, Stevens RG (1999) ‘Soil test interpretation guide.’ EC 1478. (Extension & Station Communications, Oregon State University: Corvallis, OR, USA)

McDowell R, Condron LM, Mahieu N, Brookes PC, Poulton PR, Sharpley AN (2002) Analysis of potentially mobile phosphorus in arable soils using solid state nuclear magnetic resonance. Journal of Environmental Quality 31, 450–456.
Analysis of potentially mobile phosphorus in arable soils using solid state nuclear magnetic resonance.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD38XlvVCgsbg%3D&md5=db7d5dc48f54791388c3911153f36e81CAS | 11931433PubMed |

Mekki A, Dhouib A, Sayadi S (2006) Changes in microbial and soil properties following amendment with treated and untreated olive mill wastewater. Microbiological Research 161, 93–101.
Changes in microbial and soil properties following amendment with treated and untreated olive mill wastewater.Crossref | GoogleScholarGoogle Scholar | 16427511PubMed |

Mekki A, Dhouib A, Sayadi S (2009) Evolution of several soil properties following amendment with olive mill wastewater. Progress in Natural Science 19, 1515–1521.
Evolution of several soil properties following amendment with olive mill wastewater.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BC3cXhtFequ7c%3D&md5=c66f90315aefb2ff4e9ce1e4831e58aaCAS |

Mekki A, Dhouib A, Sayadi S (2013) Review: Effects of olive mill wastewater application on soil properties and plants growth. International Journal of Recycling of Organic Waste in Agriculture 2, 15
Review: Effects of olive mill wastewater application on soil properties and plants growth.Crossref | GoogleScholarGoogle Scholar |

Mendes M, Pala A (2003) Type I error rate and power of three normality tests. Pakistan Journal of Information Technology 2, 135–139.
Type I error rate and power of three normality tests.Crossref | GoogleScholarGoogle Scholar |

Mitra GN, Sahu SK, Nayak RK (2009) Ameliorating effects of potassium on iron toxicity in soils of Orissa. In ‘The role and benefits of potassium in improving nutrient management for food production, quality and reduced environmental damage. IPI-OUAT-IPNI International Symposium’. 5–7 November 2009. (OUAT: Bhubaneswar, Orissa, India)

Moraetis D, Stamati FE, Nikolaidis NP, Kalogerakis N (2011) Olive mill wastewater irrigation of maize: Impacts on soil and groundwater. Agricultural Water Management 98, 1125–1132.
Olive mill wastewater irrigation of maize: Impacts on soil and groundwater.Crossref | GoogleScholarGoogle Scholar |

Mühlbachová G (2011) Soil microbial activities and heavy metal mobility in long-term contaminated soils after addition of EDTA and EDDS. Ecological Engineering 37, 1064–1071.
Soil microbial activities and heavy metal mobility in long-term contaminated soils after addition of EDTA and EDDS.Crossref | GoogleScholarGoogle Scholar |

Murphy DV, Cookson WR, Braimbridge M, Marschner P, Jones DL, Stockdale EA, Abbott LK (2011) Relationships between soil organic matter and the soil microbial biomass (size, functional diversity, and community structure) in crop and pasture systems in a semi-arid environment. Soil Research 49, 582–594.
Relationships between soil organic matter and the soil microbial biomass (size, functional diversity, and community structure) in crop and pasture systems in a semi-arid environment.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BC3MXhsV2kur3J&md5=4d2b40e18193b6999a8bc2f7689dc6c7CAS |

Nsouli B, Darwish T, Thomas JP, Zahraman K, Roumié M (2004) Ni, Cu, Zn and Pb background values determination in representative Lebanese soil using the thick target PIXE technique. Nuclear Instruments and Methods in Physics Research Section B 219–220, 181–186.
Ni, Cu, Zn and Pb background values determination in representative Lebanese soil using the thick target PIXE technique.Crossref | GoogleScholarGoogle Scholar |

Ohlinger R (1995) ‘Methods in soil biology.’ (Eds F Schinner, E Kandeler, R Ohlinger, R Margesin) pp. 95–97. (Springer: Berlin)

Oorts K, Ghesquiere U, Swinnen K, Smolders E (2006) Soil properties affecting the toxicity of CuCl2 and NiCl2 for soil microbial processes in freshly spiked soils. Environmental Toxicology and Chemistry 25, 836–844.
Soil properties affecting the toxicity of CuCl2 and NiCl2 for soil microbial processes in freshly spiked soils.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD28XitVais74%3D&md5=c12e2892e19beac129aa14a8d4ef303cCAS | 16566169PubMed |

Page AL, Miller RH, Keeney DR (1982) ‘Methods of soil analysis, part 2. Chemical and microbiological properties.’ Agronomy Series No. 9. (Eds CA Black et al.) (American Society of Agronomy: Madison, WI, USA)

Paredes C, Cegarra J, Roig A, Sanchez-Monedero MA, Bernal MP (1999) Characterization of olive mill wastewater (alpechin) and its sludge for agricultural purposes. Bioresource Technology 67, 111–115.
Characterization of olive mill wastewater (alpechin) and its sludge for agricultural purposes.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DyaK1cXnslOrt7k%3D&md5=225e656f53970d15fb57e7eae8c58312CAS |

Paz-González A, Taboada-Castro T, Taboada-Castro M (2000) Levels of heavy metals (Co, Cu, Cr, Ni, Pb and Zn) in agricultural soils of Northwest Spain. Communications in Plant Analysis and Soil Science 31, 1773–1783.
Levels of heavy metals (Co, Cu, Cr, Ni, Pb and Zn) in agricultural soils of Northwest Spain.Crossref | GoogleScholarGoogle Scholar |

Piotrowska A, Iamarino G, Rao MA, Gianfreda L (2006) Short-term effects of olive mill waste water (OMW) on chemical and biochemical properties of a semiarid Mediterranean soil. Soil Biology & Biochemistry 38, 600–610.
Short-term effects of olive mill waste water (OMW) on chemical and biochemical properties of a semiarid Mediterranean soil.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD28XhsF2jtrg%3D&md5=5f2ecf15bd6f873c9b1bc9e9aaa61e53CAS |

Piotrowska A, Rao MA, Scotti R, Gianfreda L (2011) Changes in soil chemical and biochemical properties following amendment with crude and dephenolized olive mill waste water (OMW). Geoderma 161, 8–17.
Changes in soil chemical and biochemical properties following amendment with crude and dephenolized olive mill waste water (OMW).Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BC3MXhs1arsLw%3D&md5=2206fa5391c6863983c66951d38a2b16CAS |

Pollak M, Favoino E (2004) Heavy metals and organic compounds from wastes used as organic fertilisers. Final Report, July 2004. ENV.A.2./ETU/2001/0024, European Commission.

Ramos-Cormenzana A, Juárez-Jiménez B, Garcia-Pareja MP (1996) Antimicrobial activity of olive mill wastewaters (alpechin) and biotransformed olive oil mill wastewater. International Biodeterioration & Biodegradation 38, 283–290.
Antimicrobial activity of olive mill wastewaters (alpechin) and biotransformed olive oil mill wastewater.Crossref | GoogleScholarGoogle Scholar |

Saadi I, Laor Y, Raviv M, Medina S (2007) Land spreading of olive mill wastewater: effects on soil microbal activity and potential phytotoxicity. Chemosphere 66, 75–83.
Land spreading of olive mill wastewater: effects on soil microbal activity and potential phytotoxicity.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD28Xht1Cqtr7O&md5=2d925da722f519b15b5164e3ed065578CAS | 16814841PubMed |

Saviozzi A, Bufalino P, Levi-Minzi R, Riffaldi R (2002) Biochemical activities in a degraded soil restored by two amendments: a laboratory study. Biology and Fertility of Soils 35, 96–101.
Biochemical activities in a degraded soil restored by two amendments: a laboratory study.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD38XisF2qt7Y%3D&md5=eed250cc68808e0905ac2faf747f5a1dCAS |

Sierra J, Marti E, Montserrat G, Cruana R, Garau MA (2001) Characterisation and evolution of a soil affected by olive oil mill wastewater disposal. The Science of the Total Environment 279, 207–214.
Characterisation and evolution of a soil affected by olive oil mill wastewater disposal.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD3MXnslWmur0%3D&md5=ef1029b804e8c93e995a91fb062531b1CAS | 11712597PubMed |

Soil Survey Staff (2010) ‘Keys to Soil Taxonomy.’ 11th edn (USDA-Natural Resources Conservation Service: Washington, DC)

Swartjes F (1999) Risk-based assessment of soil and groundwater quality in the Netherlands: Standards and remediation urgency. Risk Analysis 19, 1235–1249.
Risk-based assessment of soil and groundwater quality in the Netherlands: Standards and remediation urgency.Crossref | GoogleScholarGoogle Scholar | 1:STN:280:DC%2BD3c3ivValtg%3D%3D&md5=e839048c77f52e201bf0c796897f57a3CAS | 10765460PubMed |

Tisdal SL, Nelson WL, Beaton JB, Havlin JL (2003) ‘Soil fertility and fertilizers.’ 5th edn (Pearson Education, Inc.: New York)

Tripathi S, Kumari S, Chakraborty A, Gupta A, Chakrabarti K, Bandyapadhyay BK (2006) Microbial biomass and its activities in salt-affected coastal soils. Biology and Fertility of Soils 42, 273–277.
Microbial biomass and its activities in salt-affected coastal soils.Crossref | GoogleScholarGoogle Scholar |

Walker DJ, Bernal MP (2008) The effects of olive mill waste compost and poultry manure on the availability and plant uptake of nutrients in a highly saline soil. Bioresource Technology 99, 396–403.
The effects of olive mill waste compost and poultry manure on the availability and plant uptake of nutrients in a highly saline soil.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD2sXht1Oru77F&md5=9c26fd6638f1965001807f44f924e0d7CAS | 17275292PubMed |

Wang Q, Wang S (2008) Soil microbial properties and nutrients in pure and mixed Chinese fir plantations. Journal of Forest Research 19, 131–135.
Soil microbial properties and nutrients in pure and mixed Chinese fir plantations.Crossref | GoogleScholarGoogle Scholar | 1:CAS:528:DC%2BD1cXotFGgtb0%3D&md5=209f1fc767099e7910d2eee9bed7c212CAS |

Yang D, Zeng DH, Zhang J, Li LJ, Mao R (2012) Chemical and microbial properties in contaminated soils around a magnesite mine in northeast China. Land Degradation & Development 23, 256–262.
Chemical and microbial properties in contaminated soils around a magnesite mine in northeast China.Crossref | GoogleScholarGoogle Scholar |

Yuan BC, Li ZZ, Liu H, Gao M, Zhang YY (2007) Microbial biomass and activity in salt affected soils under arid conditions. Applied Soil Ecology 35, 319–328.
Microbial biomass and activity in salt affected soils under arid conditions.Crossref | GoogleScholarGoogle Scholar |