Soil Structure

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7a WHAT ARE physical soil properties PROPERTIES WHAT IS IT? WHY IS IT IMPORTANT? these Texture The size of soil particles, Soil texture affects soil behavior, in particular its soil properties sand, silt and clay, retention capacity for nutrients and water. affect soil function. determines the let’s take a look at what texture of a soil. they are and why they are important. let’s start with physical soil properties Structure The clumping of the soil The soil structure affects aeration, water movement, textural components of sand, conduction of heat, plant root growth and resistance silt and clay forms aggregates to erosion. Water has the strongest effect on soil and the further association structure due to its solution and precipitation of of those aggregates into minerals and its effect on plant growth. larger units forms soil structures called peds. Porosity Pore space is that part of The air space is needed to supply oxygen to plant the bulk volume that is roots and soil organisms. Pore space also allows not occupied by either the movement and storage of water and dissolved mineral or organic matter nutrients. but is open space occupied by either air or water. Ideally, the total pore space should be about half of the soil volume. Water Infiltration is the downward Infiltration indicates the soil’s ability to allow water infiltration entry of water into the soil. movement into and through the soil profile. Soil temporarily stores water, making it available for root uptake, plant growth and habitat for soil organisms. many of PHYSICAL these properties can be easily measured using simple tools check Color Soil color is caused by the minerals present and by Soil color does not affect the behavior and use of soil; the organic matter content. Soil can exhibit a wide however, it can indicate the composition of the out the soil testing range of color; grey, black, white, reds, browns, soil and give clues to the conditions that the soil is methods manual! yellows and under the right conditions green. Soil subjected to. color is described by using general terms such as “dark brown” but can also be described more technically using Munsell soil color charts. Soil Soil moisture, also known Soil moisture or soil water is important as it serves moisture as water content, is the as a carrier of plant nutrients, to regulate soil quantity of water temperature, to assist microbial activity and many contained in soil. more crucial activities that are essential for plant growth. Soil Testing MANUAL Methods Compaction Refers to the increase in Soil compaction impairs soil functions and impedes Soil Testing Methods Soil Testing soil bulk density/decrease roots penetration and water and gas exchange. Soil Doctors Global Programme in soil porosity. A farmer-to-farmer MANUAL training programme Did you know that soil CA7164EN/1/12.19 © FAO, 2019 © FAO, Thanks to the financial support of compaction can reduce crop yields by as much as 60%? .

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Basic Soil Science W
Basic Soil Science W. Lee Daniels See http://pubs.ext.vt.edu/430/430-350/430-350_pdf.pdf for more information on basic soils! [email protected]; 540-231-7175 http://www.cses.vt.edu/revegetation/ Well weathered A Horizon -- Topsoil (red, clayey) soil from the Piedmont of Virginia. This soil has formed from B Horizon - Subsoil long term weathering of granite into soil like materials. C Horizon (deeper) Native Forest Soil Leaf litter and roots (> 5 T/Ac/year are “bio- processed” to form humus, which is the dark black material seen in this topsoil layer. In the process, nutrients and energy are released to plant uptake and the higher food chain. These are the “natural soil cycles” that we attempt to manage today. Soil Profiles Soil profiles are two-dimensional slices or exposures of soils like we can view from a road cut or a soil pit. Soil profiles reveal soil horizons, which are fundamental genetic layers, weathered into underlying parent materials, in response to leaching and organic matter decomposition. Fig. 1.12 -- Soils develop horizons due to the combined process of (1) organic matter deposition and decomposition and (2) illuviation of clays, oxides and other mobile compounds downward with the wetting front. In moist environments (e.g. Virginia) free salts (Cl and SO4 ) are leached completely out of the profile, but they accumulate in desert soils. Master Horizons O A • O horizon E • A horizon • E horizon B • B horizon • C horizon C • R horizon R Master Horizons • O horizon o predominantly organic matter (litter and humus) • A horizon o organic carbon accumulation, some removal of clay • E horizon o zone of maximum removal (loss of OC, Fe, Mn, Al, clay…) • B horizon o forms below O, A, and E horizons o zone of maximum accumulation (clay, Fe, Al, CaC03, salts…) o most developed part of subsoil (structure, texture, color) o < 50% rock structure or thin bedding from water deposition Master Horizons • C horizon o little or no pedogenic alteration o unconsolidated parent material or soft bedrock o < 50% soil structure • R horizon o hard, continuous bedrock A vs.
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Soil Acidification the Unseen Threat to Soil Health and Productivity
Soil Acidification The unseen threat to soil health and productivity www.ces.vic.gov.au February 2009 Fact Sheet No. 7 This fact sheet is one of a series, developed from material presented in Victoria’s first comprehensive State of the Environment Report. The Report is a major undertaking of the Commissioner for Environmental Sustainability and covers a broad range of environmental issues affecting the State. Its purpose is to improve community understanding of Victoria’s environment, and through the use of recommendations, to ensure its protection for present and future generations. The report was released in December 2008 and is available at www.ces.vic.gov.au Key findings Acidification is also linked to erosion, salinity, and loss of soil biodiversity. Bacteria, earthworms and other soil organisms are • The cost of lost productivity to Victoria due to soil generally sensitive to soil pH and tend to decline as soils become acidification is estimated at $470 million per year. more acidic. • Soil acidification is accelerated by some land management practices and the area of acid soil is increasing. Victoria has up to 8.6 million ha of acidic soils including • Naturally acidic soils can’t be distinguished from soils 4–5 million ha of strongly acidic soils, which mostly occur acidified by agriculture. naturally and are indistinguishable from those with accelerated • The use of acidifying fertiliser, to support more intensive acidification. agriculture, is increasing in Victoria. • Only 5.5% of the area requiring treatment with lime to restore Coastal acid sulfate soils are a different category of acid soils and critical soil pH levels is sufficiently treated.
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Advanced Crop and Soil Science. a Blacksburg. Agricultural
DOCUMENT RESUME ED 098 289 CB 002 33$ AUTHOR Miller, Larry E. TITLE What Is Soil? Advanced Crop and Soil Science. A Course of Study. INSTITUTION Virginia Polytechnic Inst. and State Univ., Blacksburg. Agricultural Education Program.; Virginia State Dept. of Education, Richmond. Agricultural Education Service. PUB DATE 74 NOTE 42p.; For related courses of study, see CE 002 333-337 and CE 003 222 EDRS PRICE MF-$0.75 HC-$1.85 PLUS POSTAGE DESCRIPTORS *Agricultural Education; *Agronomy; Behavioral Objectives; Conservation (Environment); Course Content; Course Descriptions; *Curriculum Guides; Ecological Factors; Environmental Education; *Instructional Materials; Lesson Plans; Natural Resources; Post Sc-tondary Education; Secondary Education; *Soil Science IDENTIFIERS Virginia ABSTRACT The course of study represents the first of six modules in advanced crop and soil science and introduces the griculture student to the topic of soil management. Upon completing the two day lesson, the student vill be able to define "soil", list the soil forming agencies, define and use soil terminology, and discuss soil formation and what makes up the soil complex. Information and directions necessary to make soil profiles are included for the instructor's use. The course outline suggests teaching procedures, behavioral objectives, teaching aids and references, problems, a summary, and evaluation. Following the lesson plans, pages are coded for use as handouts and overhead transparencies. A materials source list for the complete soil module is included. (MW) Agdex 506 BEST COPY AVAILABLE LJ US DEPARTMENT OFmrAITM E nufAT ION t WE 1. F ARE MAT IONAI. ItiST ifuf I OF EDuCATiCiN :),t; tnArh, t 1.t PI-1, t+ h 4t t wt 44t F.,.."11 4.
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Dynamics of Carbon 14 in Soils: a Review C
Radioprotection, Suppl. 1, vol. 40 (2005) S465-S470 © EDP Sciences, 2005 DOI: 10.1051/radiopro:2005s1-068 Dynamics of Carbon 14 in soils: A review C. Tamponnet Institute of Radioprotection and Nuclear Safety, DEI/SECRE, CADARACHE, BP. 1, 13108 Saint-Paul-lez-Durance Cedex, France, e-mail: [email protected] Abstract. In terrestrial ecosystems, soil is the main interface between atmosphere, hydrosphere, lithosphere and biosphere. Its interactions with carbon cycle are primordial. Information about carbon 14 dynamics in soils is quite dispersed and an up-to-date status is therefore presented in this paper. Carbon 14 dynamics in soils are governed by physical processes (soil structure, soil aggregation, soil erosion) chemical processes (sequestration by soil components either mineral or organic), and soil biological processes (soil microbes, soil fauna, soil biochemistry). The relative importance of such processes varied remarkably among the various biomes (tropical forest, temperate forest, boreal forest, tropical savannah, temperate pastures, deserts, tundra, marshlands, agro ecosystems) encountered in the terrestrial ecosphere. Moreover, application for a simplified modelling of carbon 14 dynamics in soils is proposed. 1. INTRODUCTION The importance of carbon 14 of anthropic origin in the environment has been quite early a matter of concern for the authorities [1]. When the behaviour of carbon 14 in the environment is to be modelled, it is an absolute necessity to understand the biogeochemical cycles of carbon. One can distinguish indeed, a global cycle of carbon from different local cycles. As far as the biosphere is concerned, pedosphere is considered as a primordial exchange zone. Pedosphere, which will be named from now on as soils, is mainly located at the interface between atmosphere and lithosphere.
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Progressive and Regressive Soil Evolution Phases in the Anthropocene
Progressive and regressive soil evolution phases in the Anthropocene Manon Bajard, Jérôme Poulenard, Pierre Sabatier, Anne-Lise Develle, Charline Giguet- Covex, Jeremy Jacob, Christian Crouzet, Fernand David, Cécile Pignol, Fabien Arnaud Highlights • Lake sediment archives are used to reconstruct past soil evolution. • Erosion is quantified and the sediment geochemistry is compared to current soils. • We observed phases of greater erosion rates than soil formation rates. • These negative soil balance phases are defined as regressive pedogenesis phases. • During the Middle Ages, the erosion of increasingly deep horizons rejuvenated pedogenesis. Abstract Soils have a substantial role in the environment because they provide several ecosystem services such as food supply or carbon storage. Agricultural practices can modify soil properties and soil evolution processes, hence threatening these services. These modifications are poorly studied, and the resilience/adaptation times of soils to disruptions are unknown. Here, we study the evolution of pedogenetic processes and soil evolution phases (progressive or regressive) in response to human-induced erosion from a 4000-year lake sediment sequence (Lake La Thuile, French Alps). Erosion in this small lake catchment in the montane area is quantified from the terrigenous sediments that were trapped in the lake and compared to the soil formation rate. To access this quantification, soil processes evolution are deciphered from soil and sediment geochemistry comparison. Over the last 4000 years, first impacts on soils are recorded at approximately 1600 yr cal. BP, with the erosion of surface horizons exceeding 10 t·km− 2·yr− 1. Increasingly deep horizons were eroded with erosion accentuation during the Higher Middle Ages (1400–850 yr cal.
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Lnt. Agrophysics,1993, 7,133-140 MEASUREMENT TIME AND
lnt. Agrophysics,1993, 7,133-140 MEASUREMENT TIME AND SPATIAL VARIABILITY OF FIELD INFIL1RATION M. Kutilek, V. Kuraz, M. Krejca Department of Irrigation and Drainage, Czech Technical University in Prague Thaikurova 7, 166 29 Prague 6, Czech Republic A b s t r a c t. Infiltration studies were performed on For the estimation of some soil hydraulic arenic chemozems of quartemality fluvial terrace of Labe functions the inverse solution of inftltration is (Elbe). We studied the applicability of infiltration equations of Philip (2-pararnetric ), and 3-pararnetric, of Brutsaert and applicable as an expedient and fast method. Hy Swartzendruber, using 70 inflitration tests performed on a draulic functions and parameters of inftltration regular grid on a plot covered for 4 years by grass. The best are then used for the quantitative discussion on applicability was found for the 3-pararneter equations, but the dynamics of soil structure. Our studies there is no unique recommendation. The probability density function (PDF) of estimates of soil hydraulic characteristics were, therefore, aimed at the evaluation of the is defonned by errors of estimates due to the approximate field inftltration tests. The main problems were: character of equations used. The log-normal distribution is a 1. Field testing of quasi-analytical and ap well-acceptable approximation for sorptivity S, saturated proximative equations of infiltration. hydraulic conductivity Ks and rates of inflitration. Only for 2. Application of the tested equations to the some estimates of hydraulic functions a weak spatial va riability was found for the distance of 7.5 m. Long time va study on the long time alteration of the soil fabric riability of infiltration and its parameters after ploughing and porous system after ploughing.
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Soil Erosion
Soil erosion Soil erosion in sloping agricultural land in Tunisia. Photolibrary on soil erosion processes. The most serious form of soil degradation is from accelerated erosion. Erosion is the washing or blowing away of surface soil, sometimes down to the bedrock. While some erosion takes place without the influence of man, the soil is lost so slowly that it is usually replaced through natural processes of decay and regeneration so soil loss and creation of new soil are balanced. What keeps soil in a natural state from eroding is vegetation. Undisturbed by man, soil is usually covered by a canopy of shrubs and trees, by dead and decaying leaves or by a thick mat of grass. Whatever the vegetation, it protects the soil when the rain falls or the wind blows. The leaves and branches of trees and the cushion of grass absorb the force of raindrops, and root systems of plants hold the soil together. Even in drought, the roots of native grasses, which extend several metres into the ground, help tie down the soil and keep it from blowing away. With its covering of vegetation stripped away, however, soil is as vulnerable to damage as a tortoise without its shell. Whether the plant cover is disturbed by cultivation, grazing, burning, or bulldozing, once the soil is laid bare to the erosive action of wind and water, the slow rate of natural erosion is greatly accelerated. Losses of soil take place much faster than new soil can be created, and a kind of deficit spending begins with the topsoil.
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Micropedology to Reveal Pedogenetic Processes in Technosols Françoise Watteau, Geoffroy Séré, Hermine Huot, Frédéric Rees, Christophe Schwartz, Jean-Louis Morel
Micropedology to reveal pedogenetic processes in Technosols Françoise Watteau, Geoffroy Séré, Hermine Huot, Frédéric Rees, Christophe Schwartz, Jean-Louis Morel To cite this version: Françoise Watteau, Geoffroy Séré, Hermine Huot, Frédéric Rees, Christophe Schwartz, et al..Mi- cropedology to reveal pedogenetic processes in Technosols. Spanish Journal of Soil Science, Universia, 2018, 8 (2), pp.149-163. 10.3232/SJSS.2018.V8.N2.02. hal-02173903 HAL Id: hal-02173903 https://hal.archives-ouvertes.fr/hal-02173903 Submitted on 4 Jul 2019 HAL is a multi-disciplinary open access L’archive ouverte pluridisciplinaire HAL, est archive for the deposit and dissemination of sci- destinée au dépôt et à la diffusion de documents entific research documents, whether they are pub- scientifiques de niveau recherche, publiés ou non, lished or not. The documents may come from émanant des établissements d’enseignement et de teaching and research institutions in France or recherche français ou étrangers, des laboratoires abroad, or from public or private research centers. publics ou privés. Micropedology to reveal pedogenetic processes in Technosols Uso de la micropedología en la descripción de procesos edafogenéticos en Tecnosoles Uso da micropedologia na descrição de processos pedogenéticos em Tecnossolos AUTHORS Received: 30.03.2017 Revised: 13.11.2017 Accepted: 23.01.2018 @ 11 Watteau F. @, 1 ABSTRACT francoise.watteau@ univ-lorraine.fr Technosols are characterized by the presence of mineral and organic parent materials of technogenic origin (e.g. agricultural or urban wastes, industrial by-products, building materials, transported 1, 2 Huot H. natural materials). In view of the continual increase of such man-made soils, there is a true need of understanding their functioning and evolution.
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Color Interpretation and Soil Textures
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Soil Management for Horticulture
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A Method for Assessing Soil Structure
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Soils – Fundamental Concepts
NRCS Soil: Fundamental Concepts Scoop on Soil Educational CD May 2006 Soils – Fundamental Concepts The Soil In Perspective: A fundamental knowledge of soil science is a prerequisite to meeting the many natural resource challenges that will face humanity in the 21st Century. It is also true that the study of soils can be both fascinating and intellectually satisfying. It is in the soils that we are able to observe all of the principles of biology, chemistry, and physics at work. It is the understanding of these principles which enables us to minimize the degradation and destruction of one of our most important natural resources. Much of our life’s activities and pursuits are related to and influenced by the behavior of the soil around our houses, roads, septic and sewage disposal systems, airports, parks, farms, forests, schools, and shopping centers. It is essential that conservation professionals understand the soils on which we build and design and work. In any field of natural resources, it is important to understand the soil properties which impact the application of technology as we use it to preserve and protect our most basic natural resource, our soils. Soil Defined: We have several definitions of soil depending on the discipline providing the definition: Geologic definition – loose surface of the earth as distinguished from solid bedrock. (Support of plant life not required) Traditional definition – material which nourishes and supports growing plants. (Includes rocks, water, snow, and even air – all of which are capable of supporting plant life) Component definition – mixture of mineral matter, organic matter, water and air.
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