Soil Atlas of Latin America and the Caribbean

Transcription

1 Soil Atlas of Latin America and the Caribbean 0 pporting the sustainable use of soil LOGO OF SASSS

2 Soil in Latin America In most people s mind, the typical soils of Latin America are red in colour, deeply weathered and under tropical rain forests. However, the truth is very different. South and Central America posseses a tremendous range of soils that provide a range of life-critical environmental goods and services to humans, and the plant as a whole. Soil is one of the fundamental components for supporting life on the planet. Plants and crops are dependent on soil for the supply of water, nutrients and as a medium for growing. is calendar and the related Soil Atlas of Latin America and the Caribbean are initiatives under the EUROCLIMA programme, which aims to encourage cooperation between Latin America and the EU on climate change issues. (XX) Soil stores, filters, buffers and transforms substances that are introduced into the environment. is capability is crucial in producing and protecting water supplies and for regulating greenhouse gases. Soil is a provider of raw materials. Soil is also an incredible habitat and gene pool in excess of tonnes of live organisms can exist in a hectare of arable soil. e main partners are the European Commission (Joint Research Centre and EuropeAid Development and Cooperation), the South American Soil Science Society, e Food and Agricultural Organization of the United Nations and soil scientists from both Europe, South America and the Caribbean. e calendar aims to bring the soils of the region to the attention of everyone who deals with this critical non-renewable, natural resource that is vital for food and fibre production, a range of ecosystem services and sustainable development. Soil is a fundamental component of our landscape and cultural heritage. Broken-up Durisol in South Africa. e field has been prepared to plant grape vines. e environment of the region is enormously diverse, from deserts and seasonally dry regions in the west to the vast tropical rainforests of the Amazon basin, and from coastal lowlands with mangroves to the high mountain ranges and volcanoes of the Andes. Southern parts of the continent are covered by extensive grasslands. As a consequence, the range of soils is tremendously varied. Soil names and terminology used in the calendar is that of the World Reference Base for Soil Resources 00, a cooperative effort of the Food and Agricultural Organization of the United Nations, ISRIC-World Soil Information, and the International Union for Soil Sciences to arrive at a common language in soil science. Soil characteristics change significantly with depth. Colour differences identify soil horizons reflecting variations in the distribution of diverse materials. In the above example from xxxxxxx, a dark-coloured surface horizon containing high levels of decaying vegetation overlays a much redder horizon where clay associated with iron has accumulated. Below that, a whitish layer represents the desintegrating rock from which this soil has formed, the so-called parent material. e name for this type of soil is Haplic Luvisol (Chromic). is calendar highlights the diversity and richness of soil in Africa; it may help the reader to understand better the characteristics of soil in this part of the world.

3 Ferralsols (from Latin ferrum, iron, and aluminium) January 0 Termites colonize soils in the tropics by building up large hills and excavating deep burrows to fetch water and clay. e above photograph shows termites in action. (ww) Soils having a strongly weathered horizon with low-nutrient retention and very low amounts of weatherable minerals (ferralic horizon). ey have a strongly micro-aggregated soil structure and are fairly porous. is combination makes them less susceptible to erosion than similar soils in the tropics. is profile from xxx shows a clear plough layer up to a depth of cm. e large cavities in the plough layer are termite chambers. e mottled horizon below.0 m is plinthite, material that hardens upon repeated exposure to air and sunlight. Ferralsols occur in tropical and subtropical regions of the world, mainly on old and stable land surfaces. In South America, they occupy mainly the Amazon Basin. Ferralsols are relatively common in Latin America and are often associated with Acrisols. ey cover around xx% of the continent. : : : : 0 0

4 Plinthosols (from Greek plinthos, meaning brick) February 0 Plinthite material is used to harden road surfaces and airstrips, and, when soft, it can be cut into blocks that are used to construct buildings. e photograph above shows xxx. (JD) Soils having either a hardened layer of accumulated iron (hydr)oxides (petroplinthic horizon), or a strongly mottled layer with iron (hydr)oxides that hardens irreversibly (plinthic horizon) upon exposure to the air and sunlight. e profile above from xxx shows a Plinthosol practically devoid of vegetation. An indurated hard layer on top covers the soil below that predominantly consists of weakly cemented large iron nodules (buck shot) which can be mined. (OS) Plinthosols occur mainly in the moist tropical regions in lowlying positions where iron from the soil and adjacent uplands is accumulating. When hardened layers become exposed, they are highly resistant to erosion and become eventually the higher parts of the landscape. is phenomenon is known as landscape inversion. e map shows the location of areas where Plinthosols are the dominant soil. Plinthosols cover around % of the area shown on the map. : : : : 0 0

5 Andosols (from Japanese an, meaning black, and do, meaning soil) March 0 Snow-covered summit of unt Kenya, an extinct volcano north of Nairobi. (ISRIC) (ISRIC) Andosols form from volcanic ash, pumice, cinder and related parent materials. Many Andosols develop a thick, dark topsoil as a result of the fixing of organic substances by aluminium that is released from volcanic minerals. is profile from xxx still shows clear layering as a result of intermittent eruptions. Evidence of soil formation can be observed in the upper part of the soil (between 0 and 0 cm) where the accumulation of organic matter and homogenization has taken place. e difference in colour can be partly attributed to the weathering of iron-rich mineral (the reddish colours) and partly to the origin of the eruptive material. Andosols are highly productive soils but suffer from phosphate fixation due to a high amount of active iron in the soil. e map shows the location of areas where Andosols are the dominant soil. Andosols cover around 0.% of the area shown on the map. : : : : 0 0

6 Phaozems (from Greek phaios, meaning dusky and Russian zemlja, for earth or land) April 0 is picture shows a Phaozem area in Northern rocco which is highly valued as agricultural land. e main source of the high organic content is the abundant grass vegetation. (AR) Phaeozems are the soils of warm, wet grassland areas and are characterized by a humus-rich surface layer. Phaeozems have a high content of available calcium ions bound to soil particles, resulting in a very permeable, well-aggregated structure. Due to the presence of at least one wet period during the year, Phaozems display an absence of calcium carbonate or salt accumulation in subsurface layers.. In the above example from xxx, the dark coloured surface horizon overlies a well-structured, chestnut brown subsoil, in which below 0 cm calcium carbonate has accumulated, mainly in the form of nodules. (AR) Phaeozems are found in the South American pampas, the North American prairies and the subtropical steppes of Asia. : : : : 0 e map shows the location where Phaozems are the dominant soil. Phaozems cover around xx% of the area shown on the map. 0

7 Acrisols (from Latin acer, very acid) May 0 (OS) Because of the low inherent fertility of Acrisols, many African farmers use slash-and-burn techniques to release nutrients from the vegetation and to counteract weeds. (OS) Soils having a subsurface horizon with distinctly higher clay content (argic horizon) than the overlying horizon. ey have a low nutrient retention and a low base saturation (total amount of Ca, Mg, K and Na with respect to the cation exchange capacity). e photograph shows an Acrisol from Madagascar. e upper, yellowish coloured part has lost clay that has been leached down and been redeposited in the lower, reddish coloured part. e round pale spots are filled animal burrows (krotovinas). Acrisols are fairly susceptible to erosion and compaction because of their poorly developed soil structure. Many Acrisols are hard-setting when drying-out, which makes them very difficult to work with the conventional African farm implements like the hoe. Acrisols occur dominantly in the wetter parts of the tropics and subtropics and the warm temperate regions in relatively young landscapes. : : : : 0 e map shows the location of areas where Acrisols are the dominant soil. Acrisols cover around % of the area shown on the map. 0

8 Lixisols (from Latin lixivia, meaning washed-out substances) June 0 Ridging is a common practice on Lixisols to concentrate the soil s fertility in the rooting zone of the crop. e photograph above shows a ridged field in northern Ghana after harvest of the sorghum; the ridges remain intact during the entire cropping season. (OS) Soils having a subsurface horizon with distinctly higher clay content (argic horizon) than the overlying horizon. ey have a low nutrient retention and a high base saturation (total amount of Ca, Mg, K and Na with respect to the cation exchange capacity). Like Acrisols, they are fairly susceptible to erosion and compaction because of their poorly developed soil structure. e example above shows a Lixisol from Ghana with a cultivated shallow topsoil, a thin lighter coloured leached horizon just below, overlying a clay-rich subsoil. athering sandstone can be seen at the base of the profile. (OS) Lixisols occur dominantly in the drier parts of the tropics and subtropics. eir high base status is partly due to low leaching, and partly from inputs of airborne dust from adjacent desert regions. : : : : 0 e map shows the location of areas where Lixisols are the dominant soil. Lixisols cover around % of the area shown on the map. 0

9 Calcisols (from the Latin, calcarius, meaning lime rich) July 0 is photograph from Greece, clearly illustrates the typical Mediterranean landscapes of olive and fruit orchards that grow well in irrigated Calcisols. Soils displaying a substantial movement (translocation) and reaccumulation of calcium carbonate. e precipitation may occur in the form of hard nodules, root channels filled with fine calcite (pseudomycelium) or even in continuous layers of soft or hard lime (calcrete). is fine example from xxx and shows.. Calcisols are common on calcareous parent material (e.g. limestone) in regions with distinct dry seasons as well as in dry areas where groundwater that is rich in carbonate is close to the surface. : : : : 0 e map shows the location of areas where Calcisols are the dominant soil (covering around % of the area shown on the map). 0

10 Cambisols (from the Latin, cambire, meaning to exchange) August 0 Cambisols are common in loess (a fine-grained deposit of wind-blown material) areas and can be very productive for agriculture. A Cambisol is a young soil where the evidence of pedogenic (soil forming) processes is week and are expressed only as variations in colour and/or the development of structure below the surface horizon. Cambisols are characterized by slight or moderate weathering of parent material and by the absence of appreciable quantities of redeposited clay, organic matter, aluminium and/or iron compounds is profile shows a Cambisol from xxxxxx. Cambisols are found across a range of landscapes (level ground to mountainous terrain), in all climates and under a wide range of vegetation types. : : : : 0 e map shows the location of areas where Calcisols are the dominant soil (covering around xx% of the area shown on the map). 0

11 Solonetz (from the Russian, sol, for salt, and etz, meaning strongly expressed) September 0 is photograph shows the typical landscape of salt tolerant vegetation that accompanies Solonetz. is example comes from xxx. A strongly alkaline (i.e. not acid) soil with a high proportion of adsorbed sodium and/or magnesium ions, a subsurface horizon of clay accumulation and well developed columnar structure. lts accumulate through the evaporation of groundwater that contains high levels of sodium bicarbonate. e above example comes from xxx and shows. Solonetz are normally associated with unconsolidated materials, mostly fine-textured sediments, in flat lands in a climate with hot, dry summers or with (former) coastal deposits that contain a high proportion of sodium ions. e map shows the location of areas where Solonetz are the dominant soil (covering around xx% of the area shown on the map). : : : : 0 0

12 Leptosols (from the Greek, leptos, meaning thin) October 0 In Leptsols, rocks are often close to the surface and many outcrops are visible. is is a view of Leptosols from xxx. Leptosols are a shallow soils overlying hard rock, very gravelly or highly calcareous (lime-rich) material. Leptosols can be regarded as young soils lacking in structure as evidence of soil formation is normally limited to a thin topsoil horizon over an weekly developed subsoil or ever directly over the unaltered parent material. Leptosols on limestone are commonly called Rendzinas while those on acid rocks, such as granite, are called Rankers. is profile comes from the xxx. On a global scale, Leptosols are very extensive. ey are found mainly in mountainous regions and in areas where the soil has been eroded to the extent that hard rock comes close to the surface. e map shows the location of areas where Leptospls are the dominant soil (covering around xx% of the area shown on the map). : : : : 0 0

13 Anthrosols (from the Greek, anthropos, meaning man) November 0 e Terra Preta do Indio is one of the most famous examples of Anthrosols in the world... Anthrosols are soils that have formed through human activities such as the addition of organic materials or household wastes, irrigation or cultivation. e anthropogenic influence is usually restricted to the surface horizons which reflect the nature of the modification (e.g. deep tillage, intensive fertilisation with manure, wet cultivation). In most cases, a buried soil can still be found at some depth. is profile from xxxx shows. e group includes the Terra Preta do Indio, Paddy soils and oasis. Soils consisting of unaltered anthropogenic material' (e.g. land fill, mine waste, construction material) do not qualify as Anthrosols as they lack evidence of pedogenetic change. Anthrosols are not dominant over large areas and so are visible on the map. However, they are very important locally. : : : : 0 0

14 Planosols/Stagnosols (from Latin planus, meaning flat) December 0 (OS) A truck driving over a temporary road on one of the terraces of the Volta River in Ghana creates huge dust clouds because of lack of any cohesion between the particles in the upper part of the Planosol. (EVR) Soils having an abrupt textural change within 00 cm from the soil surface, associated with stagnic properties (waterlogging) above or below that boundary. is profile from xxx shows a typical Planosol with a structureless topsoil of about 0 cm thick. At that depth the abrupt textural change occurs and evidence of the stagnating conditions can be seen as yellowish brown mottles between 0 and 0 cm depth. During the rainy season, water stagnates on the impermeable layer in the soil for a significant period of time. is leads to the destruction of the clay particles in the upper part of the soil, a process known as ferrolysis, and to structural degradation. Planosols occur in level landscapes throughout the world often associated with broad river valleys. e map shows the location of areas where Planosols are the dominant soil. Planosols cover around xx% of the area shown on the map. : : : : 0 0

15 Soil Atlas of Latin America and the Caribbean To raise awareness of the general public, policy makers and other scientists of the global perspective and importance of soil in Africa, particularly, in the context of the sustainable use of natural resources, the European Commission s Joint Research Centre (located in Ispra, Italy) is collaborating with soil scientists from South and Central America, the Caribbean and Europe to produce the first ever SOIL ATLAS OF LATIN AMERICA AND THE CARIBBEAN. e atlas links the theme of soil characteristics with land use, environmental services with climate change with a view of enhancing our knowledge and understanding of a threatened natural resource that is vital to human existence through the sharing of information while ensuring synergies and coordination of current and future actions. e atlas illustrates the diversity of soil from the tropics to the deserts through a series of maps supported by explanatory texts, high quality photographs and descriptive graphics. e atlas illustrates the variation of soil in Latin America and the Caribbean from a local perspective. rough supporting texts, the atlas describes the major soil types found in the region, together with their principal characteristics and the main soil forming processes. Special attention is given to the relationship between climate change and soil. For more details, please see Distribution of major soil types of Latin America and the Caribbean e map shows the dominant Reference Soil Groups according to the WRB classification and correlation system. e map is the updated output of the SOTER database for Latin America produced by FAO. 0 0 '0"W 00 0 '0"W 0 0'0"W 0 0'0 "W 0 0'0"W 0 0'0 "W 0 0'0"W 0 0'0 "W 0 0'0 "N 0 0 '0"N 0'0 "N 0 '0"N re than 0 distinct soil types can be found on the South American continent as a result of its geologic history, topography, climate, and vegetation. ree major groupings correspond to the continent s primary land regions the lowlands, the highlands, and the Andes. Low natural fertility is a conspicuous feature of soils in the humid tropic regions. About half of the continent s soils consist either of unconsolidated and nutrient-poor sediments deposited in river basins, red soils leached of silica and containing residual concentrations of iron and aluminum sesquioxides and acidic soils with a bleached upper horizon that are low in lime. About one-fifth of the continent is covered by arid soils of various types in which agriculture is problematic without irrigation. Other regions, representing about 0% of the total area, are poorly drained, clayey soils in which waterlogging is common. In the Andes, slopes are often steep, and shallow soils consisting of imperfectly weathered rock fragments abound, accounting for another 0%of the continent s surface. In the inter-andean valleys and on some of the foothills, nevertheless, eutrophic soils can be found containing high levels of nutrient matter, but often shallow and subject to seasonal oxygen deficiency. Fertile soils, therefore, extend over only about 0 % of the surface. e most important of these are the deep, darkcoloured prairie soils (developed from winddeposited loess), chestnut soils, and ferruginous tropical soils. e Argentine Pampas, the largest fertile area on the continent, is uniformly covered with the socalled pampean loess, which is calcareous, rich in minerals, and mixed with volcanic sediment. In urbanized areas and near large mines, Technosols (highly disturbed soils) occur. However, they cover too small areas to be visible on the map. 0 0'0 "N 0 0 '0"N 0 0'0 "N 0 0 '0"N 0 0 '0" 0 0'0 " 0 0'0 "S 0 0 '0"S Map based on WRB interpretation 0 0 '0"W of the SOTER LAC (FAO, xxxx) 00 0 '0"W 0 0'0"W DRAFT need to include Central America and Mexico 0 0'0 "S 0 0 '0"S 0'0 "S 0 '0"S 0 0'0 "S 0 0 '0"S 0 0'0 "S 0 0 '0"S 0 0'0 "W Soil is our life-support system. It delivers food & fresh water; recycles wastes, etc. Decision makers need good baseline information about soils for planning, reducing land degradation, investment and management. e Soil Science Society of South America is a network of national societies that aims to consolidate and promote knowledge on soils by strengthening the capacity of expertise of soil scientists (training process), lobbying towards political institutions for a better consideration of soil aspects by decision makers (soil protection and conservation) and ensuring widespread diffusion of soil-related information to both specialists and the general public (awareness raining) through the xxxx website and xxxxxx regular activities. 0 0'0"W 0 0'0 "W 0 0'0"W 0 0'0 "W

16 e mission of the JRC is to provide customer-driven scientific and technical support for the conception, development, implementation and monitoring of EU policies. As a service of the European Commission, the JRC functions as a reference centre of science and technology for the Union. Close to the policy-making process, it serves the common interest of the Member States, while being independent of special interests, whether private or national. e JRC consists of seven different institutes, each with its own focus of expertise, on five separate sites around Europe. e Institutional and Scientific relations provides coordination and serves as a link between the institutes and the policymakers. Located in Ispra (Italy), the Institute for Environment and stainability is one of the seven institutes that constitute the Joint Research Centre of the European Commission. In line with the JRC mission, the aim of IES is to provide scientific and technical support to European Union strategies for the protection of the environment contributing to a sustainable development. IES works in close collaboration with official laboratories, research centres and industries of the EU's Member States, creating a bridge between the EU's policies and the European citizen. e combination of complementary expertise in the fields of experimental sciences, modelling and remote sensing puts the IES in a strong position to contribute to the implementation of the European Research Area and to the achievement of a sustainable environment. Institute for Environment and stainability Joint Research Centre of the European Commission Via Fermi I-00 Ispra (VA), Italy EUROCLIMA e EUROCLIMA programme aims to encourage cooperation between Latin America and the European Union on the problems and consequences of climate change, particularly in view of integrating these issues into sustainable development strategies. Funded by the European Commission s EuropeAid Development and Cooperation Directorate-General, the project investigates techniques for improved information and data sharing systems on scientific and socio-economic matters concerning climate change issues (and cross-cutting linkages) together with capacity building to strengthening the technical capacities of national and regional decision-makers and scientific community of Latin America. e authors of this calendar, Arwyn Jones, ra Barcelo, Ciro Gardi, Peter Schad, and other contributors and Luca ntanarella gratefully acknowledge all contributions, in particular: all contributors of images for kindly making their photographs available. European Commission Joint Research Centre, IES, Land Management & Natural Hazards Unit, SOIL Action xxxxxxxxxxxxxxxxxxxxxxxxx e pictures on the front cover of the calendar show the variety of soils across Latin America. om left to right and top to bottom: Durisol (FE), broken-up Durisol, Gypsisol, Kastanozem (AR), Andosol (ISRIC), Vertisol (ISRIC), Namibian dune, and Acrisol (OS). Further information and a high resolution image of the poster to the left can be obtained from (ED) European Communities 0 Reproduction authorised for the sole purpose of illustration for teaching or scientific research provided the source is acknowledged. Legal Notice e European Commission, nor any person acting on behalf of the Commission, does not accept any responsibility or liability whatsoever for the use which may be made of this publication.