DOCSLIB.ORG

ELECTRICAL PROPERTIES of SOILS Ph.D

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
ELECTRICAL PROPERTIES of SOILS Ph.D 1 ELECTRICAL PROPERTIES OF SOILS Ph.D. dissertation (modified) of Larisa Pozdnyakova defended in December 1999 in the Department of Renewable Resources, University of Wyoming, Laramie, WY 1999 by Larisa A. Pozdnyakova © 2003 by Landviser, LLC www.landviser.com & www.landviser.us All rights reserved Pozdnyakova, Larisa, Electrical Properties of Soils, Ph.D., Department of Renewable Resources, December, 1999. In this study, thorough analysis is conducted for soil electrical properties, i.e. electrical resistivity, conductivity, and potential. Soil electrical properties are the parameters of natural and artificially created electrical fields in soils and influenced by distribution of mobile electrical charges, mostly inorganic ions, in soils. Distributions of electrical charges and properties in various soil profiles were shown to be results of the soil-forming processes. Soil properties influencing the density of mobile electrical charges were found to be exponentially related with electrical resistivity and potential based on Boltzmann’s law of statistical thermodynamics. Relationships were developed between electrical properties and other soil physical and chemical properties, such as texture, stone content, bulk density, water content, cation exchange capacity, salinity, humus content, and base saturation measured in-situ and in soil samples. Geophysical methods of vertical electrical sounding, four-electrode probe, non-contact electromagnetic profiling, and self-potential were modified for measuring soil electrical properties and tested in different soil studies. The proposed methods are extremely efficient, reliable, and non-disturbing. Compared with conventional methods of soil analysis, the electrical geophysical methods allowed evaluating groundwater table, salt content, depth and thickness of soil horizons, polluted or disturbed layers in soil profiles, and stone content with an estimation error <10%. The methods provide extensive data on spatial and temporal variations in soil electrical properties, which relate to the distributions of other essential soil properties. The electrical properties were incorporated with the data from conventional soil analyses to enhance the estimation of a number of soil physical and chemical properties and to assist soil survey. The study shows various applications of the modified geophysical methods in soil physics, soil genesis, precision agriculture, and environmental engineering. The applications of the methods included studying soil water retention, compaction, and soil morphology; mapping soil spatial variability within fields, catenas, or landscapes; locating genetic horizons, compacted or disturbed layers, hydrocarbon pollutants, stones, and groundwater tables in soil profiles; and monitoring soil drying or freezing. 2 TABLE OF CONTENTS INTRODUCTION .......................................................................................................................................................... 5 CHAPTER I. ELECTRICAL PROPERTIES OF SOLUTIONS AND POROUS MEDIA..................................... 7 I.1. BASIC THEORY OF ELECTRICITY .............................................................................................................................. 7 I.2. SPONTANEOUS ELECTRICAL PHENOMENA IN SOLUTIONS AND POROUS MEDIA......................................................... 9 I.2.1. Electrical phenomena in electrolytic solutions................................................................................................ 9 I.2.2. Electrical phenomena in porous media......................................................................................................... 12 I.2.3. Electrical phenomena on interfaces of various media................................................................................... 14 CHAPTER II. GEOPHYSICAL METHODS FOR MEASURING ELECTRICAL PARAMETERS IN SOILS19 II.1. CLASSIFICATION OF METHODS ............................................................................................................................. 19 II.2. SELF-POTENTIAL METHOD.................................................................................................................................... 20 II.3. FOUR-ELECTRODE PROBE..................................................................................................................................... 22 II.4. VERTICAL ELECTRICAL SOUNDING....................................................................................................................... 25 II.5. ELECTRICAL TOMOGRAPHY ................................................................................................................................. 29 II.6. GROUND PENETRATING RADAR............................................................................................................................ 29 II.7. ELECTROMAGNETIC INDUCTION........................................................................................................................... 30 II.8. NON-CONTACT ELECTROMAGNETIC PROFILING.................................................................................................... 31 CHAPTER III. ELECTRICAL PARAMETERS AND SOIL PROPERTIES........................................................ 33 III.1. VOLUME DENSITY OF MOBILE ELECTRICAL CHARGES IN SOILS ........................................................................... 33 III.2. RELATIONSHIPS OF ELECTRICAL PARAMETERS AND SOIL PROPERTIES ................................................................ 34 III.3. ELECTRICAL RESISTIVITY CHANGE DURING SOIL COMPACTION........................................................................... 36 III.4. RELATIONSHIP OF ELECTRICAL RESISTIVITY AND SOIL WATER CONTENT............................................................ 39 III.5. RELATIONSHIPS OF ELECTRICAL PARAMETERS AND SOIL CHEMICAL PROPERTIES FOR VARIOUS SOILS ............... 48 III.5.1. Relationships between electrical parameters and soil properties for soils in humid areas........................ 49 III.5.2. Relationships between electrical parameters and soil properties for soils in arid areas ........................... 53 III. 6. PRINCIPLES OF APPLICATION IN-SITU ELECTRICAL MEASUREMENTS TO SOIL STUDIES........................................ 55 CHAPTER IV. APPLICATIONS OF ELECTRICAL GEOPHYSICAL METHODS IN SOIL GENESIS STUDIES....................................................................................................................................................................... 58 IV.1. ELECTRICAL PARAMETERS AND SOIL-FORMING PROCESSES................................................................................ 58 IV.2. SOIL-FORMING PROCESSES AND ELECTRICAL PARAMETERS OF SOILS IN HUMID AREAS ...................................... 60 IV.2.1. Eluvial processes ........................................................................................................................................ 60 IV.2.2. Gleyzation ................................................................................................................................................... 66 IV.2.3. Peat accumulation ...................................................................................................................................... 67 IV.2.4. Soil catena in humid areas.......................................................................................................................... 69 IV.2.5. Climatic soil sequences............................................................................................................................... 70 IV.3. SOIL-FORMING PROCESSES AND ELECTRICAL PARAMETERS OF SOILS IN SEMIARID AND ARID AREAS ................. 72 IV.3.1. Humus accumulation and calcification....................................................................................................... 72 IV.3.2. Salinization and alkanization...................................................................................................................... 73 IV.4. ELECTRICAL PARAMETERS OF CHARACTERISTIC SOIL HORIZONS........................................................................ 76 CHAPTER V. USAGE OF ELECTRICAL GEOPHYSICAL METHODS IN AGRICULTURAL RESEARCH ........................................................................................................................................................................................ 79 V.1. STUDY VALLEY AGRICULTURAL LANDSCAPES IN HUMID AREAS WITH ELECTRICAL GEOPHYSICAL METHODS ...... 79 V.2. DETECTION OF THE GROUNDWATER TABLE AND SUBSURFACE SALINITY DURING IRRIGATION AGRICULTURE IN ARID AREAS USING ELECTRICAL GEOPHYSICAL METHODS ........................................................................................... 85 ER ........................................................................................................................................................................... 90 V.3. ESTIMATING SPATIAL VARIABILITY OF SOIL SALINITY USING ELECTRICAL CONDUCTIVITY MEASUREMENTS AND GEOSTATISTICAL METHODS ......................................................................................................................................... 93 V.4. EVALUATION OF SOIL STONE CONTENT WITH ELECTRICAL GEOPHYSICAL METHODS.......................................... 102 3 CHAPTER VI. APPLICATIONS OF ELECTRICAL GEOPHYSICAL METHODS IN ENVIRONMENTAL AND CIVIL ENGINEERING ..................................................................................................................................
Load more

Recommended publications
  • Formación De Neologismos En Ciencia Del Suelo
    Formación de neologismos en Ciencia del Suelo Formation of Soil Science neologisms Formação de neologismos em Ciência do Solo AUTORES Received: 01.06.2012 Revised: 19.06.2012 Accepted: 20.06.2012 @ 1 Porta J. [email protected]. cat RESUMEN 2 Desde el Congreso de Roma de 1924, en el que la comunidad cientí!ca decidió utilizar la expresión Villanueva D. Soil Science en lugar de Pedology o Edaphology, no se ha llegado a establecer criterios para la formación en español de neologismos referentes! "# al estudio del suelo."$%#& En inglés, los nuevos términos se forman dando prioridad a la raíz griega ! " frente a la raíz # . Este criterio, que se ha consolidado !!"#" con el uso, no tiene en cuenta que en griego el término se"$%#& re!ere al suelo sobre el que se anda y @ Corresponding no al suelo en el que crecen las plantas, expresado por el término # . En el presente trabajo, desde Author una perspectiva etimológica, semántica y de pragmática lingüística, se proponen criterios para la 1 Sociedad Española formación de neologismos en español o al establecer equivalencias en español de voces introducidas de la Ciencia del en inglés. El análisis se basa en voces de autoridad; en elementos etimológicos; en aspectos de am- Suelo. Universitat de Lleida. Rovira Roure bigüedad fonética y ortográ!ca; en la revisión de equivalencias entre términos similares en español, 191, 25198 Lleida, inglés y francés; en el ámbito universitario; en la denominación de las sociedades y revistas cientí!cas; España. y en aspectos de buen gusto idiomático en determinados ámbitos geográ!cos del español.
    [Show full text]
  • National University of Engineering Ge111
    NATIONAL UNIVERSITY OF ENGINEERING COLLEGE OF ENVIRONMENTAL ENGINEERING ENVIRONMENTAL ENGINEERING PROGRAM GE111 – EDAPHOLOGY I. GENERAL INFORMATION CODE : GE111 – Edaphology SEMESTER : 5 CREDITS : 03 HOURS PER WEEK : 04 (Theory – Practices – Laboratory) PREREQUISITES : GE102 – Geography CONDITION : Mandatory II. COURSE DESCRIPTION Concept and importance of edaphological soil and its interest for Engineering. Detailed knowledge of the components, physical and chemical properties, genesis, classification and principles of cartography, of natural soils and anthropogenic urban soils. Principle of soil evaluation, as a starting point in studies of environmental planning, territorial planning and environmental impact assessment. Finally, it is intended that students understand the importance of soil as a non-renewable resource and the degradations to which its inappropriate use leads; It is also intended to train in the corrective and rehabilitating measures of degraded soils. III. COURSE OUTCOMES At the end of the course the student will: Organizes data for proper analysis and interpretation and calculations (soil densities, physical chemical and biological properties). Explains and determines the genesis of the soil, the physical properties of the soil, geo reference, physiographic units. Understand and apply densities, to determine the consistency of the soil, the probability of resistance in an earthquake. Interpret and perform types of soil sampling to take to the laboratory to determine their physical, chemical, and biological characteristics. Build models to determine the degree of contamination, is determined by the parameters, using the LMOs, ECAs, In soils. IV. LEARNING UNITS 1. SOIL GENESIS / 4 HOURS Objective of soil science: Interest in Engineering. Genesis. Pedological and edaphological approach. Factors of soil formation. Climate action. Properties of the soil affected by the climate.
    [Show full text]
  • Soil Quality: Why and How?
    Geoderma 114 (2003) 145–156 www.elsevier.com/locate/geoderma Soil quality: why and how? Douglas L. Karlena,*, Craig A. Ditzlerb, Susan S. Andrewsa a USDA-ARS National Soil Tilth Laboratory, 2150 Pammel Drive, Ames, IA 50011-4420, USA b National Soil Survey Center, 100 Centennial Mall North, Lincoln, NE 68508-3866, USA Abstract The soil quality concept evolved throughout the 1990s in response to increased global emphasis on sustainable land use and with a holistic focus emphasizing that sustainable soil management requires more than soil erosion control. The concept includes two areas of emphasis—education and assessment—both based soundly on principles of soil science. Soil quality test kits, farmer-based scorecards, visual assessment procedures, fact sheets, and video presentations were developed as educational materials because many people have no basis to recognize, understand or appreciate the complexity of soil resources. Assessment tools for indexing soil quality at various scales were pursued to show the multiple functions (e.g. nutrient and water cycling, filtering and buffering of contaminants, decomposition of crop residues and other organic matter sources, and recycling of essential plant nutrients) that soils provide as the foundation for sustainable land management. Worldwide research and technology transfer efforts have increased awareness that soil resources have both inherent characteristics determined by their basic soil formation factors and dynamic characteristics influenced by human decisions and management practices. Soil quality assessment and education are intended to provide a better understanding and awareness that soil resources are truly living bodies with biological, chemical, and physical properties and processes performing essential ecosystem services.
    [Show full text]
  • Late Holocene Climate Reconstructions for the Russian Steppe, Based on Mineralogical and Magnetic Properties of Buried Palaeosols ⁎ T
    Palaeogeography, Palaeoclimatology, Palaeoecology 249 (2007) 103–127 www.elsevier.com/locate/palaeo Late Holocene climate reconstructions for the Russian steppe, based on mineralogical and magnetic properties of buried palaeosols ⁎ T. Alekseeva a, A. Alekseev a, , B.A. Maher b, V. Demkin a a Institute of Physicochemical and Biological Problems of Soil Science, Russian Academy of Sciences, Pushchino, Russia b Centre for Environmental Magnetism and Palaeomagnetism, Lancaster Environment Centre, Department of Geography, Lancaster University, Lancaster, LA1 4YB, UK Received 10 April 2005; received in revised form 29 December 2006; accepted 15 January 2007 Abstract Insights into past climate changes, and corresponding evolution of soils and the environment, can be gained by multi- disciplinary studies of palaeosols. Here, we focus on palaeosols buried beneath archaeological monuments, specifically, funerary mounds (kurgans), in the Russian steppe. The kurgans were constructed, and each of the palaeosols buried, over a range of different timesteps from the mid-Holocene to ∼ 600 years before present (yr BP). Integrated magnetic, mineralogical and pedological data were used to obtain estimates of past climate (especially precipitation) changes, through both time and space. A soil magnetism- based climofunction, derived previously from modern steppe soils and modern climate, was applied to each set of palaeosols, to obtain quantitative reconstructions of annual precipitation for the time at which the soils were buried. Independent soil property data (clay mineralogy, salt content, iron mineralogy from Mossbauer analysis, and optical and electron microscopy) were also obtained, in order to test and substantiate the magnetic inferences. The data obtained indicate that the climate of the Lower Volga steppe area has varied from the mid-Holocene onwards.
    [Show full text]
  • Soil Erosion. LC Science Tracer Bullet. INSTITUTION Library of Congress, Washington, D.C
    DOCUMENT RESUME ED 306 075 SE 050 430 AUTHOR Buydos, John F., Comp. TITLE Soil Erosion. LC Science Tracer Bullet. INSTITUTION Library of Congress, Washington, D.C. National Referral Center for Science and Technology. REPORT NO LC-TB-88-5 PUB DATE Nov 88 NOTE llp. PUB TYPE Reference Materials - Bibliographies (131) EDRS PRICE MF01/PC01 Plus Postage. DESCRIPTORS *Agriculture; Citations (References); Earth Science; Educational Resources; *Indexes; Information Sources; Physical Sciences; *Reference Materials; Soil Conservation; *Soil Science A2STRACT Soil erosion is the detachment and movement of topsoil or soil material from the upper part of the soil profile. It may occur in the form of rill, gully, sheet, or wind erosion. Agents of erosion may be water, wind, glacial ice, agricultural implements, machinery, and animals. Soil conservation measures require a thorough understanding of the mechanics of erosion processes. Runoff, slope, rain, wind, plant care, and the presence or absence of conservation measures are some of the factors which influence the rate of erosion. Erosion results in a deterioration in the quality of cropping and grazing land in addition to reduced productivity and increased expenditure for fertilizers. It is essential to control erosion in order to maintain productivity of the soil, to reduce sedimentation in streams and lakes, and to prevent further damage to the land by gullies and ditches. Some common methods of checking erosion are control of overgrazing, construction of barriers, contour trenching, and afforestation. This guide offers a selected bibliography of the literature in the Library of Congress on soil erosion. Organization of listings include: basic texts, handbooks, bibliographics, government publications, conference proceedings, reviews, abstracting and indexing services, technical reports, and other selected materials.
    [Show full text]
  • Soils and Soil-Forming Material Technical Information Note 04 /2017 30Th November 2017
    Soils and Soil-forming Material Technical Information Note 04 /2017 30th November 2017 Contents 1. Introduction to Soils ........................................................................................................................ 2 2. Components and Properties of Soil ................................................................................................ 7 3. Describing and Categorising soils .................................................................................................. 29 4. Policy, Regulation and Roles ......................................................................................................... 34 5. Soil Surveys, Handling and Management ..................................................................................... 40 6. Recommended Soil Specifications ................................................................................................ 42 7. References .................................................................................................................................... 52 “Upon this handful of soil our survival depends. Husband it and it will grow our food, our fuel, and our shelter and surround us with beauty. Abuse it and the soil will collapse and die, taking humanity with it.” From Vedas Sanskrit Scripture – circa 1500 BC The aim of this Technical Information Note is to assist Landscape Professionals (primarily landscape architects) when considering matters in relation to soils and soil-forming material. Soil is an essential requirement for providing
    [Show full text]
  • Cadmium Publications Rejected As Not Acceptable for Plants and Invertebrates
    Interim Final Eco-SSL Guidance: Cadmium Cadmium Publications Rejected as Not Acceptable for Plants and Invertebrates Published literature that reported soil toxicity to terrestrial invertebrates and plants was identified, retrieved and screened. Published literature was deemed Acceptable if it met all 11 study acceptance criteria (Fig. 3.3 in section 3 “DERIVATION OF PLANT AND SOIL INVERTEBRATE ECO-SSLs” and ATTACHMENT J in Standard Operating Procedure #1: Plant and Soil Invertebrate Literature Search and Acquisition ). Each study was further screened through nine specific study evaluation criteria (Table 3.2 Summary of Nine Study Evaluation Criteria for Plant and Soil Invertebrate Eco-SSLs, also in section 3 and ATTACHMENT A in Standard Operating Procedure #2: Plant and Soil Invertebrate Literature Evaluation and Data Extraction, Eco-SSL Derivation, Quality Assurance Review, and Technical Write-up.) Publications identified as Not Acceptable did not meet one or more of these criteria. All Not Acceptable publications have been assigned one or more keywords categorizing the reasons for rejection ( Table 1. Literature Rejection Categories in Standard Operating Procedure #4: Wildlife TRV Literature Review, Data Extraction and Coding). Rev (NRCC) National Research Council of Canada. 1979. Effects of Cadmium in the Canadian Environment. NRCC No.16743, Associate Committee on Scientific Criteria for Environmental Quality, National Research Council of Canada, Ottawa , 148 Media Abdel-Lateif, H. M., Donker, M. H., and Van Straalen, N. M. 1998. Interaction between temperature and cadmium toxicity in the isopod Porcellio scaber. Functional Ecology 12[4], 521-527 Mix Abdul Rida, A. M. 1996. <Translated> Concentrations and growth of earthworms and plants in soils contaminated by cadmium, copper, iron, lead and zinc: interactions soil- earthworm.
    [Show full text]
  • History and Interpretation of Soil Enzyme Activity
    History and Interpretation of Soil Enzyme Activity By Sara Annette Liu Major Paper M.S. in Soil & Water Sciences University of Florida Soil and Water Sciences Department Introduction Microbial communities play a key role in ecosystem-level processes such as decomposition of organic matter, nutrient cycling (Wright and Reddy, 2001), and processes affecting the efficiency of nutrient cycling and ecosystem function (Yao et al., 2000). These microbial processes include the release of extracellular enzymes, which function to convert complex organic molecules to simple organic constituents during decomposition of organic material (Prenger, J. P. and K. R. Reddy, 2004). Soil enzymes are protein structured molecules that increase the reaction rate by catalyzing them without any permanent transformation (Dick and Kandeler, 2004). The substance acted upon by a soil enzyme is called a substrate (Fig. 1). Figure 1. Enzyme acting as a catalyst to breakdown complex substrates to bioavailable products that are more easily accessible to microorganisms. The enzymatic reaction cleaves the substrate and releases a product, which can be a nutrient contained in the substrate. Enzyme production is a function of microbial activity which is regulated in part by nutrient availability (Sinsabaugh, 1994), where microbes produce enzymes to mobilize resources from compound sources when nutrients are limited (Harder and Dijikhuizen, 1983). These soil enzymes play an important role in biochemical process of organic matter recycling, soil physical properties, and microbial activity and/or biomass (Table 1) (Cherukumalli et al, 2017). The study of soil enzymology has provided insight to the function of enzymatic activity as an indicator of ecosystem biogeochemical processes, nutrient availability, rates of nutrient and carbon cycling, and even response to climate change.
    [Show full text]
  • Digital Mapping of Soil Associations and Eroded Soils (Prokhorovskii District, Belgorod Oblast) A
    ISSN 1064-2293, Eurasian Soil Science, 2021, Vol. 54, No. 1, pp. 13–24. © Pleiades Publishing, Ltd., 2021. Russian Text © The Author(s), 2021, published in Pochvovedenie, 2021, No. 1, pp. 17–30. GENESIS AND GEOGRAPHY OF SOILS Digital Mapping of Soil Associations and Eroded Soils (Prokhorovskii District, Belgorod Oblast) A. P. Zhidkina, *, M. A. Smirnovaa, b, A. N. Gennadievb, S. V. Lukinc, Ye. A. Zazdravnykhd, and N. I. Lozbeneva aDokuchaev Soil Science Institute, per. Pyzhevskii 7, Moscow, 119017 Russia bLomonosov Moscow State University, Leninskie Gory 1, Moscow, 119999 Russia cBelgorod State University, ul. Pobedy 85, Belgorod, 308015 Russia. dBelgorod Agrarian Center, ul. Shchorsa 8, Belgorod, 308027 Russia *e-mail: [email protected] Received April 19, 2020; revised May 24, 2020; accepted June 17, 2020 Abstract—A new method of digital mapping of the soil cover pattern with calculation of the share of soils of different taxa and degree classes for soil erosion in the soil associations is proposed. A comparative analysis of soil maps obtained using different methods of construction (visual expert and digital) and with their differ- ent contents (displaying the dominant soil or soil associations) has been performed. In the case of mapping by the visual expert method (with the display of the dominant soil), a significant underestimation of the total area of moderately and strongly eroded soils in comparison with the digital mapping is noted. These differ- ences are due to the underestimation of the area of small polygons with moderately and strongly eroded soils in the composition of soil associations on slopes of low steepness and in shallow hollows in the visual expert method of mapping.
    [Show full text]
  • Soil Classification Following the US Taxonomy: an Indian Commentary
    See discussions, stats, and author profiles for this publication at: http://www.researchgate.net/publication/280114947 Soil Classification Following the US Taxonomy: An Indian Commentary ARTICLE · JULY 2015 DOI: 10.2136/sh14-08-0011 DOWNLOADS VIEWS 21 27 1 AUTHOR: Tapas Bhattacharyya International Crops Research Institute for Se… 110 PUBLICATIONS 848 CITATIONS SEE PROFILE Available from: Tapas Bhattacharyya Retrieved on: 19 August 2015 provided by ICRISAT Open Access Repository View metadata, citation and similar papers at core.ac.uk CORE brought to you by Published July 17, 2015 Review Soil Classification Following the US Taxonomy: An Indian Commentary T. Bhattacharyya,* P. Chandran, S.K. Ray, and D.K. Pal More than 50 yr ago US soil taxonomy was adopted in India. Since then many researchers have contributed their thoughts to enrich the soil taxonomy. The National Bureau of Soil Survey and Land Use Planning (NBSS & LUP) (Indian Council of Agricultural Research) as a premier soil survey institute has been consistently using benchmark soil series to understand the rationale of the soil taxonomy, keeping in view the soil genesis from different rock systems under various physiographic locations in tropical India. The present review is a humble effort to present this information. ne of the fundamental requirements of any natural science minerals, higher categories of soil classification were conceptu- Ois to classify the proposed bodies or the objects stud- alized (Duchaufour, 1968). The concept of genetic profiles was ied (Joel, 1926). Soils do not exist as discrete objects like plants used in early and current Russian soil classification schemes and animals but occur in nature as a complex and dynamic (Gerasimov, 1975; Gorajichkin et al., 2003).
    [Show full text]
  • Basic Soil Properties
    Soil: Definition and Basic Properties Allen Hayes, Soil Scientist, NCDA, Division of Soil & Water Conservation Soil Defined: USDA-Natural Resources Conservation Service ▪ “Soil…is a natural body comprised of solids (minerals and organic matter), liquid, and gases that occurs on the land surface, occupies space, and is characterized by one or both of the following: ▪ horizons, or layers, that are distinguishable from the initial material as a result of additions, losses, transfers, and transformations of energy and matter ▪ or the ability to support rooted plants in a natural environment.” (Soil Survey Staff, 1999) Soil Defined: USDA-Natural Resources Conservation Service ▪ “…a natural body…” ▪ Forms naturally in terrestrial ecosystems ▪ Not man-made Soil Defined: USDA-Natural Resources Conservation Service ▪ “comprised of solids (minerals and organic matter), liquid, and gases…” Soil Defined: USDA-Natural Resources Conservation Service ▪ “…occurs on the land surface,…” ▪ “…occupies space…” ▪ Has “horizons, or layers, that are distinguishable from the initial material as a result of additions, losses, transfers, and transformations of energy or matter, or ▪ Has “the ability to support rooted plants in a natural environment” Soil Formation (briefly) ▪ Soil vs. Dirt ▪ Soil forming factors ▪ Parent material, climate, biology, relief and time ▪ North Carolina has about 400 soil series ▪ United States has about 20,000 soil series Soil Defined ▪ “Nature has endowed the Earth with glorious wonders and vast resources that man may use for his own ends. Regardless of our tastes or our way of living, there are none that present more variations to tax our imagination than the soil, and certainly none so important to our ancestors, to ourselves, and to our children.” -Dr.
    [Show full text]
  • Role of Arthropods in Maintaining Soil Fertility
    Agriculture 2013, 3, 629-659; doi:10.3390/agriculture3040629 OPEN ACCESS agriculture ISSN 2077-0472 www.mdpi.com/journal/agriculture Review Role of Arthropods in Maintaining Soil Fertility Thomas W. Culliney Plant Epidemiology and Risk Analysis Laboratory, Plant Protection and Quarantine, Center for Plant Health Science and Technology, USDA-APHIS, 1730 Varsity Drive, Suite 300, Raleigh, NC 27606, USA; E-Mail: [email protected]; Tel.: +1-919-855-7506; Fax: +1-919-855-7595 Received: 6 August 2013; in revised form: 31 August 2013 / Accepted: 3 September 2013 / Published: 25 September 2013 Abstract: In terms of species richness, arthropods may represent as much as 85% of the soil fauna. They comprise a large proportion of the meso- and macrofauna of the soil. Within the litter/soil system, five groups are chiefly represented: Isopoda, Myriapoda, Insecta, Acari, and Collembola, the latter two being by far the most abundant and diverse. Arthropods function on two of the three broad levels of organization of the soil food web: they are plant litter transformers or ecosystem engineers. Litter transformers fragment, or comminute, and humidify ingested plant debris, which is deposited in feces for further decomposition by micro-organisms, and foster the growth and dispersal of microbial populations. Large quantities of annual litter input may be processed (e.g., up to 60% by termites). The comminuted plant matter in feces presents an increased surface area to attack by micro-organisms, which, through the process of mineralization, convert its organic nutrients into simpler, inorganic compounds available to plants. Ecosystem engineers alter soil structure, mineral and organic matter composition, and hydrology.
    [Show full text]