Major soil groups of the world ecology, genesis, properties and classification

Tai Lieu Chat Luong Jean-Paul Legros an informa business www.taylorandfrancisgroup.com 6000 Broken Sound Parkway, NW Suite 300, Boca Raton, FL 33487 711 Third Avenue New York, NY 10017 Park Square, Milton Park Abingdon, Oxon OX14 4RN, UK Jean-Paul Legros Jean-Paul Legros K16058 Major Soil Groups of the World Major Soil Groups of the World Major Soil Groups of the World About the Book About the Book About theSoils Book Soils of the exhibit considerable diversity both both in their features, of world the world exhibit considerable diversity in their features, Soilsproperties of the world exhibit considerable diversity both in their features, and in their ages and genetic conditions Thorough knowledge of of properties and in their ages and genetic conditions Thorough knowledge properties and in their ages and genetic conditions Thorough knowledge of thesethese characteristics is indispensable for the utilization and and characteristics is indispensable for study, the study, utilization theseconservation characteristics is indispensable for the study, utilization and of the natural environment This profusely illustrated book conservation of the natural environment This profusely illustrated book conservation ofanthe natural environment profusely illustrated book givesgives an exhaustive account of theofprincipal types of soils ourofplanet The The exhaustive account theThis principal types of of soils our planet gives an exhaustive account of of theweathering principal types of soils of our planet “progressive descent of weathering fronts” model, recognized and The used by by “progressive descent fronts” model, recognized and used “progressive descent of weathering fronts” model, recognized and used by eminent international scientists is the guiding principle of choice to link the eminent international scientists is the guiding principle of choice to link the eminent international is the principle of coherent choice to link observations and scientists to give the reader a synthetic and viewthe of theof the observations and to give theguiding reader a synthetic and coherent view observations and to give the reader a synthetic and coherent view of the differentiation of soils In each case, the introductory reminders summarize differentiation of soils In each case, the introductory reminders summarize differentiation of soils In each case, the introductory reminders summarize the the physicochemical and mineralogical principles necessary for for physicochemical and mineralogical principles necessary the understanding physicochemical and mineralogical principles necessary for the text The The nomenclatures rely rely systematically and and understanding the text nomenclatures systematically understanding the text The nomenclatures rely systematically and simultaneously on the two most commonly used classifications: Soil Soil simultaneously on the two most commonly used classifications: simultaneously on the two most commonly used classifications: Soil Taxonomy and World Reference Base This reference manual is particularly Taxonomy and World Reference Base This reference manual is particularly Taxonomy andatWorld Reference Base reference isdegree particularly directed students of theof Bachelor's and Master's degree courses, but isbut is directed at students the This Bachelor's and manual Master's courses, directed at students of the Bachelor's and Master's degree courses, but is also intended for workers and scientists in this subject area (geologists, also intended for workers and scientists in this subject area (geologists, also pedologists, intended for workers and scientists in this subject area (geologists, agronomists, land-use planners, foresters, etc.) as well foras allfor all pedologists, agronomists, land-use planners, foresters, etc.) as as well pedologists, agronomists, land-use planners, foresters, etc.) as well as for all thosethose concerned with or interested in protection of the environment concerned with or interested in protection of the environment those concerned with or interested in protection of the environment Jean-Paul Legros is an is agricultural scientist and has Doctorate in Science Jean-Paul Legros an agricultural scientist andahas a Doctorate in Science Jean-Paul Legros is an agricultural scientist and has a Doctorate in Science He has spent almost his entire career in the Institut National de la Recherche He has spent almost his entire career in the Institut National de la Recherche He has spent almost(INRA) his entire in the Institut National dealso la Recherche Agronomique at career Montpellier (France) He has taught for a for a Agronomique (INRA) at Montpellier (France) He has also taught Agronomique (INRA) at Montpellier (France) He has also taught for a dozen yearsyears as anas Invited Professor at theatÉcole Polytechnique Fédérale de de dozen an Invited Professor the École Polytechnique Fédérale dozen years as an Invited Professor at the École Polytechnique Fédérale de Lausanne He has been President of the Association Franỗaise pour l'ẫtude Lausanne He has been President of the Association Franỗaise pour l'ẫtude Lausanne He beenand President of the Franỗaise l'ẫtude du Sol President of Association theofAcadémie des Sciences et Lettres of of du(2009-2010), Solhas (2009-2010), and President the Académie despour Sciences et Lettres du Sol (2009-2010), and President of the Académie des Sciences etfrom Lettres Montpellier (2008) He wrote the book Mapping of the Soil, theofsame Montpellier (2008) He wrote the book Mapping of thealso Soil, also from the same Montpellier (2008) He wrote the book Mapping of the Soil, also from the same publisher publisher publisher V.A.K Sarma retired in 1994 as Principal Scientist (Pedology) fromfrom the the V.A.K Sarma retired in 1994 as Principal Scientist (Pedology) V.A.K Sarma retired in 1994 as Principal Scientist (Pedology) from the National Bureau of Soil Survey and Land Use Planning, an institute of the National Bureau of Soil Survey and Land Use Planning, an institute of the National Bureau of Soil Survey and Land Use Planning, an institute of the Indian Council of Agricultural Research He had worked on the Indian Council of Agricultural Research He earlier had earlier worked on the Indian Council of Agricultural Research He had earlier worked on the faculties of the Indian Agricultural Institute at New Delhi, Punjab faculties of the Indian Agricultural Institute at New Delhi, Punjab faculties of the Indian Agricultural Institute New Delhi, Agricultural Punjab Agricultural University in Ludhiana, andatand Government Agricultural University in Ludhiana, Government Agricultural Agricultural University in Ludhiana, and Government Agricultural College, Thiruvananthapuram, India College, Thiruvananthapuram, India College, Thiruvananthapuram, India Major Soil Groups Major Soil Groups Major Soil Groups of the World of the World of the World Ecology, Genesis, Properties Ecology, Genesis, Properties Ecology, Genesis, Properties and Classification Classification and and Classification Jean-Paul Legros Jean-Paul Legros Jean-Paul Legros Translated from French by by Translated from French Translated from French by V.A.K Sarma V.A.K Sarma V.A.K Sarma A Science Publishers Book Major Soil Groups of the World Ecology, Genesis, Properties and Classification This page intentionally left blank Major Soil Groups of the World Ecology, Genesis, Properties and Classification Jean-Paul Legros Directeur de Recherche (h) Institut National de la Recherche Agronomique (INRA) Montpellier, France Translated from the French by V.A.K Sarma p, A SCIENCE PUBLISHERS BOOK CRC Press Taylor & Francis Group 6000 Broken Sound Parkway NW, Suite 300 Boca Raton, FL 33487-2742 © 2012 by Taylor & Francis Group, LLC CRC Press is an imprint of Taylor & Francis Group, an Informa business No claim to original U.S Government works Version Date: 20120829 International Standard Book Number-13: 978-1-4665-0243-7 (eBook - PDF) This book contains information obtained from authentic and highly regarded sources Reasonable efforts have been made to publish reliable data and information, but the author and publisher cannot assume responsibility for the validity of all materials or the consequences of their use The authors and publishers have attempted to trace the copyright holders of all material reproduced in this publication and apologize to copyright holders if permission to publish in this form has not been obtained If any copyright material has not been acknowledged please write and let us know so we may rectify in any future reprint Except as permitted under U.S Copyright Law, no part of this book may be reprinted, reproduced, transmitted, or utilized in any form by any electronic, mechanical, or other means, now known or hereafter invented, including photocopying, microfilming, and recording, or in any information storage or retrieval system, without written permission from the publishers For permission to photocopy or use material electronically from this work, please access www.copyright.com (http://www.copyright.com/) or contact the Copyright Clearance Center, Inc (CCC), 222 Rosewood Drive, Danvers, MA 01923, 978-750-8400 CCC is a not-for-profit organization that provides licenses and registration for a variety of users For organizations that have been granted a photocopy license by the CCC, a separate system of payment has been arranged Trademark Notice: Product or corporate names may be trademarks or registered trademarks, and are used only for identification and explanation without intent to infringe Visit the Taylor & Francis Web site at http://www.taylorandfrancis.com and the CRC Press Web site at http://www.crcpress.com Epigraph ‘Rhazes said, in his book The Physics of Auscultation, that with time rock changes to clay according to the action of the sun and of rain’ In: The Book of Agriculture by IBN-AL-AWAN, Arab author who lived in Seville in the 12th century, citing Rhazes, Arab physician of the 10th century [(from the French translation of J.J Clément-Mullet (1864)] This page intentionally left blank Introduction Objectives The objectives of this book are the following: • to explain the mechanisms of formation of the soils seen on our Planet; • for this, to present a unifying viewpoint: the weathering-front model This approach is introduced in Chapter 3; it is developed later in the various chapters of the second part, except in the very last that it does not pertain to; • to extend the idea to our understanding of nature; we profit from the study of certain mechanisms for explaining what every inquisitive naturalist can observe while strolling and travelling; for example, the appearance of karsts, the phenomenon of willo’-the-wisp, the red tropical landscapes, etc Soil Science is one of the gateways to understand better and love our Earth Readership This book is addressed to students who have soil science courses in their studies, to geographers and geologists, to agronomists and, lastly, to lovers of nature who wish to know it better The essential prerequisites are limited to some elementary concepts in chemistry Pedagogic aspects This book provides a foundation When one has read it, the vocabulary and concepts being included, one should find it easy to tackle all scientific publications, even specialized and difficult, covering the same subjects It starts out with discussion of the very mature soils that required millions of years to form and ends with the soils affected by processes that have to be studied on the scale of a month or even a minute Thus there is a progressive slide from pedogenesis to dynamics Descent of weathering fronts explains the general differentiation of soils but does viii Introduction not concern present-day dynamics, for example the rapid movements of oxygen or of salts Thus, the unifying view is no longer mentioned in Chapters 12 and 13 But we revisit it in the conclusion because it is central to the concepts that underpin this book The order of presentation is also chosen to enable the reader to easily acquire, one by one, the ideas the totality of which is necessary for understanding a chapter further along in the text Beyond that, the chapters are largely independent Where required, cross-references are made The content is centered on a dozen major soil groups This is not exhaustive but will suffice to explain the main principles We have wanted to avoid a heavy and useless ‘catalogue’ In the matter of classification, the terminology of the World Reference Base (WRB) that is accepted in a large part of the world serves as our language But the terms in Soil Taxonomy are also provided To make easy the decoding of the latter we have systematically split the terms into the formative elements For example, we write Verm-ust-oll instead of Vermustoll (Chernozem) However, in this book, typology is simplified and indicative It gives only the paths for later tackling the manuals devoted to these questions Moreover, if knowing how to name a thing is relevant, understanding its dynamics and functions is otherwise exciting… We have distinguished what has been agreed to by all from what is poorly understood or still debatable Pedology is a living science Its difficulties are not hidden Point of view and limitations In this book, all that touches on humus, biology and organic matter has been kept to the minimum They are treated specially when it is essential to so, as in the case of Andosols, Podzols and soils saturated with water Our point of view, therefore, is partial but not biased When an infant takes its first steps, the psychologist says ‘He has succeeded in learning that one can live outside his mother’s skirts’, the physician indicates ‘He now has the mechanical means of fighting against gravity’ and the neurologist adds ‘Coordination of movement is henceforth established’ All of them are right Fortunately, there is no single point of view for admiring the Earth and its major soils Unless otherwise mentioned, the soils studied here are found where there have been no disruption such as colluviation, aeolian deposition, lateral slippage, truncation by erosion, etc In other words, we examine the broad mechanisms but not the infinite variety of cases in which they weaken, particularly on slopes Introduction ix Typical plan of a chapter The following sections are always presented in a highly structured manner: • prerequisites (e.g., concept of amorphous material in the case of Andosols); • distinctive characteristics of the soil under study; • ecology and distribution in the world; • genesis and dynamics, age; • paths for an agronomic approach But the sequence of sections varies slightly from one chapter to another according to pedagogic imperatives Acknowledgements It is easier to accomplish a synthesis sitting at a comfortable desk than facing mosquitoes in Amazonia, the heat in the fringes of the Sahara or the storms in the mountains if it is required to take hydraulic measurements when water is flowing Thanks, therefore, firstly to the field workers whose work I have used Thanks also to Patrick Herrmann, who gave me, for many years, the opportunity to teach pedogenesis within the framework of Montpellier SupAgro I am grateful to all the scientists who consented to proofread the chapters according their specialization: Messrs R Bertrand, L Bock, M Bornand, G Bourrié, K Djili, J-C Favrot, F Feder, P Herrmann, S Marlet, P Quantin, P Ross, J.P Rossignol, D Schwartz and, very specially, J-P Party who reread the entire book Thanks to the publishers who believed in me as much for the French version (PPUR) as for the English version (Science Publishers) I am particularly thankful to the INRA (Institut National de Recherche Agronomique), where I spent my whole career, for providing the necessary facilities so that the updating of the French version of this book could be carried out in a good scientific environment And many thanks to V.A.K Sarma who translated the text into English with great care not only with regard to style but also to the content, as he is a soil scientist himself The exchanges with him were very pleasant I am grateful to my wife, children and grandchildren, who picked up the habit of supporting me whether present or absent, mind elsewhere, roaming the Earth, keeping fingers poised over a computer keyboard… Thanks to my father whom I neglected too much during all these years devoted to synthesis and writing Saline Soils: Solonchaks and Solonetz 441 be reduced by devising optimum technologies for desalinization and irrigation Irrigated area Canal for supply of fresh water C olorado Canal for supply of fresh water Salton Sea CALIFORNIA Reservoir Drainage system MEXICO Overall view Detailed view Fig 13.19 Distribution of water and drainage in the Coachella valley in California CONCLUSION In summary, for the best use of an environment with salinity problems, it is necessary to the following in space and time: • detect the origin of the salts, • examine the characteristics of the soils (salinity, sodicity, pH, permeability, presence of crystalline salts…), • level the land if necessary, • calculate irrigation and drainage requirements; draw up the development plan for the area; establish installations (for application of fresh water and elimination of drainage water, pumping stations, etc.); examine the durability of the system (simulations), • take the soils to an appropriate condition (preliminary leaching, fertilization, gypsum applications for saturating the exchange complex with Ca, etc.), • select tolerant and remunerative crops, • monitor all year round the movement of fresh water and used water (maintenance of canals), check the changes in salinity of the irrigation water, of drainage water and of the soils, and also monitor the state of the crop Regarding saline environments, the main thing has long been understood since most of the concepts brought out in this chapter were covered in a basic publication, hardly outdated, which has had the 442 Major Soil Groups of the World honour of having been digitized for publication on the Internet as a historic document: Saline and Alkali Soils (USDA 1954) Since that time, we have known how to bring saline soils under cropping, at least in technologically advanced countries such as Australia (Peck and Hatton) But in many regions, technological difficulties on the one hand and economic obstacles on the other are considerable and have caused many projects to fail, especially in the downstream portions of the stream courses because saline waters accumulate there (Barbiéro et al 2004; Banat et al 2006; Yoshinobu et al 2006) A quick glance through Google Earth is revealing: in the dry countries, we discover many irrigated areas that have been abandoned… APPENDIX: BRIEF GLOSSARY FOR SALINE SOILS Black crust: efflorescence of carbonate and bicarbonate of sodium There is alkalization (pH > 8.5) with consequent dispersion of clays and organic matter, and also phytotoxicity Chott: Arabic word meaning beach Around saline lakes of the high plains of Algeria, wrongly called ‘chott’, the slopes of access to the sebkra are chott in the strict sense of the word (J.H Durand) Foggara: subterranean system of capture and channelling of water It consists of a narrow tunnel cut manually, generally deeper than a permeable surface formation overlying impermeable hard rock The tunnel intercepts the water and leads it by gravity to the point it is utilized Vertical wells, regularly spaced, serve as air ducts, access for digging, and then maintenance of the system Halite: another name for sodium chloride, NaCl Halomorphic soil: one of the many names for saline soils Hygroscopic crust or even wet crust: efflorescence containing plenty of MgCl2 and possibly CaCl2 Mangrove swamp: saline, organic marsh located on the shore of a warm sea In the strict sense, mangrove means mangrove trees In the broad sense, it also includes marshes with halophytes Natron: Na2CO3, 10H2O Sebha or Sebkra: Arabic term signifying a depression rendered infertile by accumulation of salts The saline lakes of the high plateaus of North Africa are sebkra (J.H Durand) Shorre: grassy zone on the sea shore flooded only at very high tides Slikke: mud flats that can be furrowed with small channels Equivalent to poto-poto of the tropical zone Saline Soils: Solonchaks and Solonetz 443 REFERENCES Al Droubi A, B Fritz and Y Tardy, 1976 Équilibres entre minéraux et solutions Programmes de calcul appliqués la prédiction de la salure des sols et des doses optimales d’irrigation Cah ORSTOM, Sér Pédol 14 (1): 13-38 Amezketa E and R Aragüés, 1995 Hydraulic conductivity, dispersion and osmotic explosion in arid-zone soils leached with electrolyte solutions Soil Sci., 159: 287-295 Banat KM, FM Howari and MB Abdullah, 2006 Mineralogy and hydrochemical characteristics of the late marshes and swamps 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Marcel Dekker pp 149-181 Franzen D, 2005 Managing Saline Soils in North Dakota (www.ext.nodak edu) Furquim SAC, L Barbiéro, RC Graham, JP (de) Queiroz-Neto, RP Dias Ferreira and S Furian, 2010 Neoformation of micas in soils surrounding an alkaline-saline lake of Pantanal wetland, Brazil Geoderma, 158: 331-342 Gallez A, M Stitou and JE Dufey, 1981 Dessalage et désodification d’un sol marocain irrigué Agronomie, (4): 265-272 Gueddari M, 1984 Géomorphologie et Thermodynamique des Évaporites Continentales Étude du Lac Natron en Tanzanie et Étude du Chott el Jerid en Tunisie Mémoire no 76, Sciences Géologiques, CNRS 143 pp + app Saline Soils: Solonchaks and Solonetz 445 Jacoby B, 1994 Mechanisms involved in salt tolerance by plants In: Handbook of Plant and Crop Stress Mohammad Pessarakli (ed.), Marcel Dekker pp 97-123 Job JO, 1992 Les Sols Salés de l’Oasis d’El Guettar Thèse Université de Montpellier II 150 pp Job JO and G Cochonneau, 1985 Bilion: un programme de calcul des bilans ioniques et des ions appariés dans les solutions Journées Informatiques sur l’Application de l’Informatique la Valorisation des Données Physico-chimiques, Doc ORSTOM, Bondy 14 pp Kovda VA, 1977 Arid land irrigation and soil fertility: problems of salinity, alkalinity, compaction In: Arid Land Irrigation in Developing Countries E.B Worthington (ed.) pp 211-235 Laraque A, 1991 Comportement Hydrochimique des Aỗudes du Nordeste Brộsilien Semi-aride Evolution et Prộvision pour un Usage en Irrigation Thèse, Université de Montpellier II – ORSTOM 315 pp + app Loyer JY, 1991 Classification des sols salés: les sols salic Cah ORSTOM, Sér Pédol 26 (1): 51-61 Maas EV and GJ Hoffman, 1977 Crop salt tolerance, current assessment Journal of the Irrigation and Drainage Division, American Society of Civil Engineers, 103 (IR2): 115-134 Machín J and A Navas, 1998 Spatial analysis of gypsiferous soils in the Zaragoza province (Spain), using GIS as an aid to conservation Geoderma, 87: 57-66 Mees F and A Singer, 2006 Surface crust on soils/sediments of the southern Aral Sea basin, Uzbekistan Geoderma, 136: 152-159 Meyer L, 1997 Étude du Transport des Sels au Cours des Écoulements et de l’Évolution des Propriétés Physiques du Sol au Contact de Différentes Solutions Salines Travail pratique de diplôme, EPFL Lausanne, Génie Rural et IATE 38 pp + app Paquet H, G Bocquier and G Millot, 1966 Néoformation et dégradation des minéraux argileux dans certains solonetz solodisés et Vertisols du Tchad Bull Ser Carte Géol Als Lorr 19 (3-4): 295-322 Paris-Pireyre N, 1988 Les plantes en milieu salé Bull Acad Sci et Lettres de Montpellier, 19: 165-172 Peck AJ and T Hatton, 2003 Salinity and the discharge of salts from catchments in Australia Journal of Hydrology, 272: 191-202 Pédro G, 1979 Caractérisation générale des processus de l’altération hydrolytique Science du Sol, 2-3: 93-105 Pons Y and A Gerbaud, 2005 Classification agronomique des sols de marais partir de la relation entre sodicité et stabilité structurale Étude et Gestion des Sols, 12 (3): 229-243 446 Major Soil Groups of the World Rengasamy P, 2002 Sodic soils, processes, characteristics and classification In: Encyclopedia of Soil Science, Rattan Lal (ed.), Marcel Dekker pp 1221-1223 Rhoades JO, 1974 Drainage for salinity control In Drainage for Agriculture, Van Schilfaarde (ed.) Amer Soc Agronomy Monograph, 17: 433-462 Ribolzi O, V Vallès and L Barbiéro, 1993 Contrôle géochimique des eaux par la formation de calcite en milieu méditerranéen et en milieu tropical Arguments d’équilibre et argument de bilan Science du Sol, 31 (1/2): 77-95 Rieu M, R Vaz, F Cabrera and F Moreno, 1998 Modelling the concentration or dilution of saline soil-water systems European Journal of Soil Science, 49: 53-63 Rogel JÁ, RO Silla, NV de Oro and FA Ariza, 2001a The application of the FAO and US soil taxonomy systems to saline soils in relation to halophytic vegetation in SE Spain Catena, 45: 73-84 Rogel JÁ, RO Silla and FA Ariza, 2001b Edaphic characterization and soil ionic composition influencing plant zonation in a semiarid Mediterranean salt marsh Geoderma, 99: 81-98 Rogers ME and DW West, 1993 The effects of rootzone salinity and hypoxia on shoot and root growth in Trifolium species Annals of Botany, 72: 503-509 Servant J, 1970 Étude expérimentale de l’influence des conditions salines sur la perméabilité des sols – Conséquences pédologiques Science du Sol, 2: 87-101 Servant J, 1974 Sur le rôle des cristaux de chlorure de sodium dans la genèse d’une structure poudreuse la surface de certains sols salés C.R Acad Sci Paris, 278 (série D): 589 Servant J, 1975 Contribution l’Étude Pédologique des Terrains Halomorphes L’exemple des Sols Salés du Sud-ouest de la France Thèse, Université Montpellier 194 pp + app Servant J, 1978 La salinité dans les sols et les eaux: caractérisation et problèmes d’irrigation-drainage Bull du BRGM (2nd series), section III, no 2: 123-142 Servant J and E Servat, 1966 Introduction l’étude des sols salés littoraux du Languedoc-Roussillon Ann Agron 17 (1): 53-73 Szabolcs I, 1994 Soils and salinization In: Handbook of Plant and Crop Stress Mohammad Pessarakli (ed.), Marcel Dekker pp 3-11 Tardy Y and JY Gac, 1979 Contrôle de la composition chimique des solutions par la précipitation des minéraux dans les sols Science du Sol, 2-3: 107-123 Tejada M, C Garcia, JL Gonzalez and MT Hernandez, 2006 Use of organic amendment as a strategy for saline soil remediation: influence on the Saline Soils: Solonchaks and Solonetz 447 physical, chemical and biological properties of soil Soil Biology and Biochemistry, 38: 1413-1421 Thomson WW, 1975 The structure and function of salt glands In Plants in Saline Environments, A Poljakoff-Mayerber and J Gale (eds.), Springer-Verlag pp 118-146 USDA, 1954 Diagnosis and Improvement of Saline and Alkali Soils Handbook no 60 159 pp Vallès V, 1985 Étude et Modélisation des Transferts d’Eau et de Sels dans un Sol Argileux, Application au Calcul des Doses d’Irrigation Thèse Institut National Polytechnique de Toulouse Vallès V, 1988 Porsal, modèle de prévision de la localisation des sels et minéraux dans les micro-sites de la porosité Science du Sol, 26 (1): 13-28 Visconti F, JM (de) Paz and JL Rubio, 2010 What information does electrical conductivity of soil water extracts of one to five ratio (w/v) provide for salinity assessment of agricultural irrigated lands? Geoderma, 154: 387-397 Wang YR, SZ Kang, L Fu-Sheng, L Zhang and JL Zhang, 2007 Saline water irrigation scheduling through a crop-water-salinity production function and a soil-water-salinity dynamic model Pedosphere, 17: 303-317 Wildes RA, 1983 Irrigation with saline groundwater as a strategy for salinity control in the Shepperton region of northern Victoria In: Salinity in Watercourses and Reservoirs, RH French (ed.) pp 255-264 Yoshinobu K, T Yano, T Honna, S Yamamoto and K Inosako, 2006 Causes of farmland salinization and remedial measures in the Aral Sea basin – Research on water management to prevent secondary salinization in rice-based cropping system in arid land Agricultural Water Management, 85: 1-14 Zhang F T Tiyip, JL Ding, NT Gregory and HE Qi-Sheng, 2009 The Effects of the Chemical Components of Soil Salinity on Electrical Conductivity in the Region of the Delta Oasis of Weigan and Kuqa Rivers, China Agricultural Sciences in China, 8: 985-993 14 Chernozems; General Conclusions Many other soils will remain to be studied However, the poorly differentiated young-looking soils, for example, Regosols, Leptosols, Fluvisols or even Umbrisols, raise fewer questions on genesis and are, therefore, conceptually less interesting than the rest This means that we could comprehend the broad lines of their evolution without devoting specific chapters to them For Cryosols of the Arctic regions, many aspects remain to be discovered, so that the time has not come, at least for the author of this book, to present their genesis The Chernozem can also give rise to a simplified presentation Also, the Americans have not deigned to individualize it in their Soil Taxonomy But it is a well-known soil and most classifications make reference to it In Europe, it is the fourth soil group by area (Ibáñez et al 2009) Furthermore, it will enable us to revisit climatic zonality of soils, which is at the core of pedogenesis and by which we have begun as well as we will end this book, before a few words in conclusion 14.1 THE CHERNOZEM The term comes from chern (black, in Russian) and zemlja (land or region, in the same language) Chernozem (WRB), alias Tchernozem or Tchernoziom, is very famous Firstly, the English gave it great publicity when one of them declared on his return from Russia ‘The Tchernozem is to Russia what coal is to England’ (Boulaine 2006) Then, it was while studying this soil for his thesis that the father of pedology, Vassiliyevitch Dokuchaev, discovered the fundamentals of pedogenesis When he went to Paris on the occasion of the World Fair of 1900, this person took care to take along with him a six-cubic-metre block of Chernozem This sample Chernozems; General Conclusions 449 was displayed in the Russian Pavilion, at the foot of the Eiffel Tower There is, in Russia, an agricultural research station devoted to study of the Tchernozem Societies of soil science have added to the glory of Tchernozem by naming it Soil of the Year 2005! Description The Chernozem is deep, black, humus-rich (up to 16%) about 50 cm or, at times, m deep (Fig 14.1) Its structure is granular, distinct and stable It constitutes an extraordinary ‘garden soil’ over millions of hectares The vertical profile is poorly differentiated, although accumulations of CaCO3, gypsum and even salts are sometimes found at a depth of two or three metres The soil is base-saturated with pH near Its cation exchange capacity is high, around 50 cmol (+) kg–1 Biological activity is high Small burrowing animals (rats and specialized squirrels) are active Their burrows, filled with material from the upper horizons of the soil, are krotovinas Fig 14.1 Left, typical Chernozem of Germany with krotovinas (Profile DE 014 from ISRIC-ISIS database, Wageningen, Netherlands); right, cultivated to potato in Poland (photo G Trouche, Dijon, France) Ecology and distribution Generally, Chernozems overlie deep loess deposited south of the great icecaps that covered the North of the planet in the cold periods of the Quaternary These soils occur under an annual rainfall of 350–500 mm In their major Euro-Asiatic area, they form a kind of strip with 450 Major Soil Groups of the World boundaries more or less parallel to the latitudes They have escaped the depletion phenomena that begin further north in the Phaeozems (kind of precursors of continental Luvisols) They also have kept clear of the phenomena of calcification and salinization that take place further south in Kastanozems and Solonchaks In short, Chernozems correspond to very fertile regions They are a little cold but are perfectly well suited to certain crops: wheat, potato, etc This applies in particular to Ukraine, the wheat granary of Russia and in the heartland of North America, the Corn Belt (Dakota, Minnesota, Montana, Nebraska, Iowa, etc.) The complete climatosequence of continental soils comprises, from north to south: Cryosols, Podzols, Albeluvisols, Luvisols, Phaeozems, Chernozems, Kastanozems, Solonchaks, Solonetz and, lastly, sandy deserts Figure 14.2 presents the terms of this progression that concerns us here The Chernozem, which corresponds to a P – PET not very far from zero, is therefore the least differentiated vertically Fig 14.2 Typical sequence in the continental areas From left to right: Phaeozem or Luvic Chernozem of Poland with the beginnings of clay depletion from the surface and start of a light-coloured horizon (photo: G Trouche); typical Chernozem of Germany, rich in organic matter (photo: Elke Schulz); Kastanozem with accumulation of CaCO3 in the B horizon (photo: A Ruellan); and, lastly, Solonchak with accumulation of salts on the surface (photo: A Ruellan) Figure 14.3 illustrates the distribution of these soils in North America, East Europe and Asia It has been drawn from the FAO Soil Map of the World In Eastern Europe and Asia, zonality is almost perfect On the other hand, it is much less discernible in North America because of all kinds of disruptions: less massive continent, therefore less shielded from marine influence, more heterogeneous geological substratum, mountain ranges oriented north to south, etc It was better to be Russian than American Chernozems; General Conclusions 451 Fig 14.3 Distribution of the principal continental soils at the scale of North America, Europe and Asia; from the FAO map for discovering, in the nineteenth century, the climatic zonality of soils! This remark is not intended to lessen the merits of Dokuchaev but to underscore the fact that luck is always important in the matter of scientific discovery There was at least one precursor to Dokuchaev: the Frenchman Anatole Leroy-Beaulieu (12 February 1842–5 June 1912), historian, geographer and essayist Exactly ten years before Dokuchaev published his thesis on Russian Tchernozems, Leroy-Beaulieu (1873) published an article in Revue des Deux Mondes In it he perfectly described three pedoclimatic bands, that of Chernozems, that of the ‘fertile steppes’ (Kastanozems) and that of saline soils of the south (Solonetz) From Asia and Russia, Chernozems go westward and reach Vienna (Austria) and very surely up to the central part of Germany (Dultz and Kühn 2005) In France, soils related to Chernozems are found in two regions protected from westerly winds by mountainous massifs and thereby benefiting from particularly dry continental climates (annual rainfall close to 500 mm) They are found on the one hand in the Limagne, in the lee of the Monts Dômes and on the other hand, leeward of the Vosges mountains in the Alsace plain The areas involved are small, but the black soils of Limagne (local name) are the best soils of France! Genesis Chernozems have a positive carbon balance Actually, they are developed under grassland and this is favourable for the accumulation of humus (Chap 2, § 2.5.3) Also, they started their development a long time ago, at the retreat of the last glaciation (Khokhlova et al 2001) On the other hand, the cold winters and dry summers of the continental regions 452 Major Soil Groups of the World not promote mineralization of organic matter Lastly, the calcium they contain protects carbonaceous materials But the utilization of these soils for intensive farming (irrigation, fertilization, ploughings, etc.) enhances biological activity and mineralization Chernozems are under threat of becoming, over time, ordinary soils, that is, poor in humus! Classification Table 14.1 concerns the classification of continental soils, restricted to the closest relatives of Chernozems The exact equivalents in Soil Taxonomy are hard to give We should not forget that the ancestor of Soil Taxonomy, the first version of the 7th Approximation, was conceived by Guy Smith, Director of Soil Survey Investigations of the USDA in 1952, that is to say, at the peak of McCarthyism in USA This was an epoch in which it was unimaginable to call the soils of USA by Russian names! Thus, the Americans knowingly clouded the issue and buried the Kastanozems and Chernozems within the Mollisols! Table 14.1 The soils of continental climates arranged from the north to the south in the Northern Hemisphere; only the Chernozems (16-4%) and the Kastanozems (4-2%) are really rich in humus WRB Soil Taxonomy Equivalent old terms Phaeozem Alb-oll Grey Forest soil, Brunizem Chernozem Ud-oll and Ust-oll Tchernoziom Kastanozem Xer-oll Steppe Chestnut soil Calcaric Cambisol Xer-oll Sierozem (Russian) The block of Chernozem, brought by Dokuchaev to the World Fair, remained in Paris and was offered to the Sorbonne University Professor Gèze broke off a fragment that he carried to the institution where he taught Geology, the Institut National Agronomique Broken and cracked with age, the piece could have ended up in the dustbin The young generations, who have lost the sense of beauty, have seen only dirty coal dust where a relic should be imagined Very fortunately, a vestigial residue has been saved It is today preserved at Orléans, in the stores of the INRA-INFOSOL unit GENERAL CONCLUSIONS We have put soils back in the more general framework of evolution of the ‘altérites’ of geologists, that is to say, in a context where Chernozems; General Conclusions 453 the principal phenomena are: geochemical wasting and the appearance of weathering fronts In the tropical zone, the corresponding manifestations are spectacular and, therefore, relatively easy to observe In the present book, we have attempted to generalize to the temperate environments where the weathering fronts are nothing but the horizon boundaries The phenomena are certainly less distinct because the periods of pedogenesis are shorter and weathering less drastic But the laws of physics and chemistry remain the same all over the Earth… Soil is nothing but a residue By being weathered, it slowly dissolves, collapses into itself and is differentiated vertically at the cost of considerable loss of material that disappears This is the essential fact as proved by the weathering balances It is thus wrong to focus pedogenetic studies on vertical transport of some substances (iron, aluminium, carbon, clay, calcium carbonate and various salts) through the skeleton grains (sands + silts) Of course all this does happen and is clearly visible, but these are superimposed, accessory processes It is necessary to think of this when we wish to understand the genesis of Luvisols and of Podzols It is the same thing in Ferralsols in which only what is left behind is seen, that is, at times less than 15 per cent of the original material! The progress achieved in the last decade in dating methods, and also increase in the number of analyses done, leads us to revise the ages earlier assigned to soils In fact, many profiles were differentiated over time periods too long to allow us consider as invariant their topographic, hydrological and climatic environments Lake Chad was enormous 6000 years ago Therefore, the local Vertisols were submerged since their age is 40,000 years! We can multiply examples Many soils are thus ‘polyphasic’ and have under gone a long history full of tribulations and various vicissitudes The pedogenetic mechanisms that we have presented account for the differentiation of the most typical soils but neglect the problems that have affected many others We have already said this in the introduction: we not pretend to explain all the cases Fewer than a dozen processes are sufficient to understand the essentials of diversity of soils of the world: collapse of the profile on itself, desilication, rubefaction, anoxia, salinization, etc Pedogenesis is easy! Of course, the discipline still suffers from a vocabulary hard to comprehend For example, the terms in Soil Taxonomy have frightened many scientists and petrified in place more than one farmer 454 Major Soil Groups of the World But this difficulty in mastering the terminology has come in handy as a pretext for many to exempt themselves from minimal knowledge in Soil Science Can one reasonably farming, study physical geography and geomorphology, and build urban housing, airports or highways, etc., without considering the soils? Finally we hope that the youngest readers of this book, educated in the extraordinary and superb diversity of soils of the world and the patrimonial wealth they represent, will become the direct actors in a novel approach to the protection and utilization of the natural environment REFERENCES Boulaine J, 2006 Le chernozem chez les franỗais Lettre de lAssociation Franỗaise pour l’Étude du Sol, 77 11 pp Dultz S and P Kühn, 2005 Occurrence, formation, and micromorphology of gypsum in soils from the Central-German Chernozem region Geoderma, 129: 230-250 Ibáñez JJ, R Pérez-Gómez and F San José Martinez, 2009 The spatial distribution of soils across Europe: A fractal approach Ecological Complexity, 6: 294-301 Khokhlova OS, SN Sedov, AA Golyeva and AA Khokhlov, 2001 Evolution of Chernozems in the Northern Caucasus, Russia during the second half of the Holocene: carbonate status of paleosols as a tool for paleoenvironmental reconstruction, Geoderma, 104: 115-133 Leroy-Beaulieu A, 1873 La Russie et les Russe La nature russe, le tchernoziom et la population Revue des Deux Mondes, 15 August issue, pp 737-778 Jean-Paul Legros an informa business www.taylorandfrancisgroup.com 6000 Broken Sound Parkway, NW Suite 300, Boca Raton, FL 33487 711 Third Avenue New York, NY 10017 Park Square, Milton Park Abingdon, Oxon OX14 4RN, UK Jean-Paul Legros Jean-Paul Legros K16058 Major Soil Groups of the World Major Soil Groups of the World Major Soil Groups of the World About the Book About the Book About theSoils Book Soils of the exhibit considerable diversity both both in their features, of world the world exhibit considerable diversity in their features, Soilsproperties of the world exhibit considerable diversity both in their features, and in their ages and genetic conditions Thorough knowledge of of properties and in their ages and genetic conditions Thorough knowledge properties and in their ages and genetic conditions Thorough knowledge of thesethese characteristics is indispensable for the utilization and and characteristics is indispensable for study, the study, utilization theseconservation characteristics is indispensable for the study, utilization and of the natural environment This profusely illustrated book conservation of the natural environment This profusely illustrated book conservation ofanthe natural environment profusely illustrated book givesgives an exhaustive account of theofprincipal types of soils ourofplanet The The exhaustive account theThis principal types of of soils our planet gives an exhaustive account of of theweathering principal types of soils of our planet “progressive descent of weathering fronts” model, recognized and The used by by “progressive descent fronts” model, recognized and used “progressive descent of weathering fronts” model, recognized and used by eminent international scientists is the guiding principle of choice to link the eminent international scientists is the guiding principle of choice to link the eminent international is the principle of coherent choice to link observations and scientists to give the reader a synthetic and viewthe of theof the observations and to give theguiding reader a synthetic and coherent view observations and to give the reader a synthetic and coherent view of the differentiation of soils In each case, the introductory reminders summarize differentiation of soils In each case, the introductory reminders summarize differentiation of soils In each case, the introductory reminders summarize the the physicochemical and mineralogical principles necessary for for physicochemical and mineralogical principles necessary the understanding physicochemical and mineralogical principles necessary for the text The The nomenclatures rely rely systematically and and understanding the text nomenclatures systematically understanding the text The nomenclatures rely systematically and simultaneously on the two most commonly used classifications: Soil Soil simultaneously on the two most commonly used classifications: simultaneously on the two most commonly used classifications: Soil Taxonomy and World Reference Base This reference manual is particularly Taxonomy and World Reference Base This reference manual is particularly Taxonomy andatWorld Reference Base reference isdegree particularly directed students of theof Bachelor's and Master's degree courses, but isbut is directed at students the This Bachelor's and manual Master's courses, directed at students of the Bachelor's and Master's degree courses, but is also intended for workers and scientists in this subject area (geologists, also intended for workers and scientists in this subject area (geologists, also pedologists, intended for workers and scientists in this subject area (geologists, agronomists, land-use planners, foresters, etc.) as well foras allfor all pedologists, agronomists, land-use planners, foresters, etc.) as as well pedologists, agronomists, land-use planners, foresters, etc.) as well as for all thosethose concerned with or interested in protection of the environment concerned with or interested in protection of the environment those concerned with or interested in protection of the environment Jean-Paul Legros is an is agricultural scientist and has Doctorate in Science Jean-Paul Legros an agricultural scientist andahas a Doctorate in Science Jean-Paul Legros is an agricultural scientist and has a Doctorate in Science He has spent almost his entire career in the Institut National de la Recherche He has spent almost his entire career in the Institut National de la Recherche He has spent almost(INRA) his entire in the Institut National dealso la Recherche Agronomique at career Montpellier (France) He has taught for a for a Agronomique (INRA) at Montpellier (France) He has also taught Agronomique (INRA) at Montpellier (France) He has also taught for a dozen yearsyears as anas Invited Professor at theatÉcole Polytechnique Fédérale de de dozen an Invited Professor the École Polytechnique Fédérale dozen years as an Invited Professor at the École Polytechnique Fédérale de Lausanne He has been President of the Association Franỗaise pour l'ẫtude Lausanne He has been President of the Association Franỗaise pour l'ẫtude Lausanne He beenand President of the Franỗaise l'ẫtude du Sol President of Association theofAcadémie des Sciences et Lettres of of du(2009-2010), Solhas (2009-2010), and President the Académie despour Sciences et Lettres du Sol (2009-2010), and President of the Académie des Sciences etfrom Lettres Montpellier (2008) He wrote the book Mapping of the Soil, theofsame Montpellier (2008) He wrote the book Mapping of thealso Soil, also from the same Montpellier (2008) He wrote the book Mapping of the Soil, also from the same publisher publisher publisher V.A.K Sarma retired in 1994 as Principal Scientist (Pedology) fromfrom the the V.A.K Sarma retired in 1994 as Principal Scientist (Pedology) V.A.K Sarma retired in 1994 as Principal Scientist (Pedology) from the National Bureau of Soil Survey and Land Use Planning, an institute of the National Bureau of Soil Survey and Land Use Planning, an institute of the National Bureau of Soil Survey and Land Use Planning, an institute of the Indian Council of Agricultural Research He had worked on the Indian Council of Agricultural Research He earlier had earlier worked on the Indian Council of Agricultural Research He had earlier worked on the faculties of the Indian Agricultural Institute at New Delhi, Punjab faculties of the Indian Agricultural Institute at New Delhi, Punjab faculties of the Indian Agricultural Institute New Delhi, Agricultural Punjab Agricultural University in Ludhiana, andatand Government Agricultural University in Ludhiana, Government Agricultural Agricultural University in Ludhiana, and Government Agricultural College, Thiruvananthapuram, India College, Thiruvananthapuram, India College, Thiruvananthapuram, India Major Soil Groups Major Soil Groups Major Soil Groups of the World of the World of the World Ecology, Genesis, Properties Ecology, Genesis, Properties Ecology, Genesis, Properties and Classification Classification and and Classification Jean-Paul Legros Jean-Paul Legros Jean-Paul Legros Translated from French by by Translated from French Translated from French by V.A.K Sarma V.A.K Sarma V.A.K Sarma A Science Publishers Book