Envirothon+Soils+Page

Kim: Notes for: []

//__ Master Horizons and Layers __// : · O horizons- dominated by organic material · A horizons- mineral horizons below an O horizon, show obliteration of the original rock structure, have accumulated humified organic matter mixed with the mineral fraction, have properties resulting from cultivation, pasturing or similar disturbances · E horizons- mineral horizons, main feature is loss of silicate clay, iron, aluminum, or some combination of these, leaving a concentration of resistant materials · B horizons- formed below an A, E or O horizon dominated by obliteration of the original rock structure and show: illuvial concentration of silicate clay, iron, humus, etc., removal of carbonates, residual concentrations of sesquioxides, coatings of sesquioxides that are redder in hue than overlaying and underlying horizons, alterations that form silicate clay or liberates oxides forming granular, blocky or prismatic structure if volume changes accompany changes in moisture content, brittleness · C horizons- layers that are little affected by pedogenic processes (excluding bedrock), may be either like or unlike that from which the solum presumably formed, may have been modified even if there is no evidence of pedogenesis · R layers- hard bedrock sufficiently coherent to make hand digging impractical

Notes for: []

// Land Judging and Soil Evaluation: // · A soil profile is a vertical cross-section cutting through different soil layers · Profiles can be divided into layers w/ different appearances and properties called soil horizons · Soil texture is the grouping of soil particles into different size classes: sand, silt and clay · O horizon is composed of leaf litter & moderately decomposed organic matter · A horizon is the surface soil and is a layer of accumulation of organic matter, usually dark brown to black in color · E horizon is lighter- colored with almost no organic matter and is about the same texture as the overlaying A horizon · B horizon (subsoil) is the zone of accumulation of clay and other inorganic compounds, usually the brightest colored and has a higher clay content · C horizon is partially weathered geological parent material, lower in clay and frequently shows rock structure in soils · The surface layer thickness is measured from the top of the mineral soil · Soils are composed of mineral matter, organic matter and spaces holding air and water (pores) · The proportion of each particle size group in any given soil sample is termed soil texture and can be estimated by feeling the soil in a moist state · Textural classes are named according to the particle-size group that is dominant · Most names are not single words but are a combination of 2-3 names · “loam” is used when the soil-particle-size groups are “evenly-acting” (the proportions of sand, silt, and clay are nearly equal) · Clay has a stronger control over the properties of soils (it takes less clay for its properties to be expressed) · Soil-textural classes and their relationships according to the actual particle percentages are given in the textural triangle · Precise measurement of particle-size distribution requires a lengthy laboratory procedure · Sand feels harsh and gritty · Silt feels like talcum because they are flat and about the same size as talcum powder · Clay particles stick to each other and to other particles making the soil moldable · The more clay a soil contains the more plastic it is   · A flow chart can be used to estimate textural classes using moist to wet soil · Dominant subsoil colors can be shades of red, brown, yellow, or gray · Subsoils are either one color or mottled · Red, brown and yellow are produced by oxides and hydroxides of iron coated soil particles · Subsoil colors can be used to identify soils w/ wetness problems · Under wet conditions, iron compounds are chemically altered to a more easily dissolved form · The occurrence of gray subsoil mottles or colors indicates that a soil is saturated · This info is used to determine need for agricultural drainage systems · Red, brown or yellow colors indicate soils weathered under well-drained conditions · Dark red subsoils also indicate either very old soil or soil weathered from rocks high in iron · Another property inferred from color is permeability · Clayey red, brown or yellow subsoils indicate slow or moderate permeability · Sandy and loamy subsoils red, brown or yellow in color indicate moderate to rapid permeability · Steepness of slope is important in estimating the rate of runoff and predicting the hazard of erosion · Slope is estimated in percent or as the rise (or fall) per 100 ft of distance · 2 stakes placed 100ft apart will be used as sighting stakes and the slope between them will be measured · Slope classes are usually designated by letters w/ class A being the flattest and class F being the steepest · The soil pit is located on 1 simple slope segment · Most landscapes have a variety of slope shapes/gradients · Erosion is the detachment and transport of soil particles by wind or water · In order to estimate how much erosion has occurred these must be determined: original surface layer thickness, original sequence/thickness of subsurface and subsoil layers, incorporation of subsurface and subsoil layers in the present plow layer · Erosion classes: None to slight (mostly the original surface layer), Moderate (plow layer consists of the original subsurface layer plus some subsoil), Severe (plow layer consists of mostly subsoil material   · Position of a soil in the landscape can influence its properties and potential use    · A basic understanding of soil-landscape relations is necessary to study soil    · Upland ridge summits- landforms that form the upper part of the local landscape setting    · Side slopes- slopes leading off the ridges towards some lower flatter landforms    · Foot slopes- slopes at the base of slide slopes that are usually more gently sloping than side slopes, slope towards some flatter landforms at a lower elevation    · Alluvial landscapes is the general term used for landscapes formed from sediments deposited by wind/water usually flat areas    · Flood plains are the lowest landscapes immediately along streams · Stream terraces are old floodplains above the new flood level · Drainageways are landscapes associated w/ drains or intermittent streams, resemble miniature flood plains · Inferred soil properties are those that cannot be easily measured or are combination or interaction of slope, texture, structure, vegetative cover and time · Soil structure is very important in inferring characteristics · Soil structure is the manner in which individual soil particles form compound soil units or peds · Several basic shapes of structural units are recognized in soils: massive (individual soil particles do not bind together), prismatic (individual units are bounded by flat or slightly rounded vertical faces), columnar (units are similar to prisms and are bounded by flat or slightly rounded vertical faces), blocky (units are block-like or polyhedral bounded by flat or slightly rounded surfaces that are casts of the faces of surrounding peds), platy (the units are flat and platelike), Granular (units are approximately spherical or polyhedral, bounded by curved or very irregular faces that are not casts of adjoining peds) · Infiltration rate is the rate at which rainfall enters the soil surface · Surface runoff is affected by slope, slope length, surface texture, vegetative cover. Infiltration rate and the intensity and duration of rainfall · If the soil surface is vegetated, the rate of surface runoff can be greatly decreased · A stable forest growing on a loamy soil will have slow runoff but the same soil w/ grass cover will have a high rate of runoff · Once a soil becomes saturated regardless of texture, slope, or vegetative cover, the surface runoff rate will be high · Permeability is the rate that water moves or percolates downward, it is controlled by soil texture, structure, bulk density, pore size and quantity, root channels and animal/insect burrows · Texture and structure are used to estimate soil permeability · Soil drainage is the result of the interaction of several soil properties · Excessively drained soils do not hold enough water for optimum plant growth · Poorly drained soils are opposite in that they are so wet, crops can only be grown if they are artificially drained · Excess water is a problem in moderately well, somewhat poorly and poorly drained soils, retaining sufficient water w/in the rooting depth to supply plant needs is equally important · Water does not cause mottling and is called “plant-available water” · Excessively drained soils usually cannot hold adequate available water · The land-capability-classification system groups soils w/ similar potential for agricultural production into 8 classes · With the exception of class I, soils in each are separated into subclasses on the basis of one or more minor problems: erosion hazard, wetness, unfavorable soil properties, climate · **// Class I //** - has no subclasses, suited to a wide range of plants, nearly level, deep, well-drained, easily worked, hold water well and have sufficient nutrients · **// Class II //** - some natural conditions that require conservation practices, limitations are slight and practices easy to apply · **// Class III //** - one or more moderate limitations on use, more restricted in crops, conservation is more difficult to implement, limitations restrict the amount of clean cultivation · **// Class IV //** - suitable for only occasional or limited cultivation, when cultivated they require careful management, flooding may prevent planting/harvesting, poorly drained · **// Class V //** - level but has some conditions that limit its use to pasture/range, woodland or wildlife habitat, limitations other than erosion · **// Class VI //** - soils w/ very severe limitations that make it generally unsuited for cultivation, may be well or poorly suited as woodland, some soils are well adapted to long-term meadows or sodden orchards · **// Class VII //** - soils w/ very severe limitations that make it unsuited for cultivation and restrict its use to pasture, woodland or wildlife habitat, but some special crops w/ unusual management practices can be grown, soils range from well to poorly suited for woodland · **// Class VIII //** - soils w/ severe limitations that prevent its use for commercial plant production, rocky outcrops, sand beaches, river wash, mine tailings and other nearly barren areas, a few can be altered to make suitable for cropland use · **// Major factors that keep land out of Class I //** : slope, erosion, depth, permeability, runoff, wetness, flooding, texture · **// Soil Amendments //** : lime (used to correct soil acidity and provide nutrients), nitrogen (applied to every plant except legumes, fixes microbes that fix atmospheric nitrogen), phosphorus (needed except when soil test is high, expressed at % phosphate), potassium (needed except when test is high, expressed as % potash) · Generally, water becomes a limiting factor in obtaining the max. potential yield of a soil · It is assumed that all of the plant’s nutritional needs can be supplied by fertilizer and lime applications to the surface layer · Land management systems involve both crop rotation and tillage systems · Tillage involves no long-term soil modifications · Surface residue management involves leaving as much crop residue exposed or only slightly mixed into the surface layer thus enhancing infiltration and reducing erosion · Minimum tillage and/or residue management should be used in all row crop · No-till planting is not given as an option b/c it is almost always a good replacement for any tillage practice · Mechanical practices serve to reduce a soil limitation within a given land class so the soil can be utilized more intensively without degradation · No treatment needed: class I land, class II where there are no erosion or drainage problems or class VII or VIII land where no return can be expected · Farming on the contour or strip cropping is used on soils to reduce erosion (class II, III and IV) · Tile drainage is used to permanently lower the water table or increase runoff (soils where seasonal water tables are at depths of 18 inches or less   · Control brush/trees for soils that are capable of growing crops or improved pasture where brush/trees are too big to be removed by normal tillage operations    · Control gullies by establishing grassed waterways and by filling and grading, best for heavily eroded soils w/ gullies    · When using soil for non-agricultural purposes. The emphasis shifts from surface to subsurface soil properties    · Infrequent catastrophic events, such as flooding are much more important in most non-agricultural uses    · Limitation categories are defined as: slight (properties favorable for the planned use and present few problems), moderate (only moderately favorable, limitations can be overcome or modified w/ special maintenance), severe (one or more unfavorable properties, difficult to overcome limitations) · The final limitation is based on the most restrictive soil-site property · The most limiting factor will control the use · **// Properties to be evaluated: //** · **// Texture //** - 4 general classes: the general class of sands, the general class of loams and clay loams and the two clay classes (low shrink-swell and high shrink-swell) shrink-swell is the relative change in volume on wetting and drying, estimated according to plasticity · **// Permeability //** - same classes are used but rate of flow are considered · **// Depth to Rock //** - class limits are based on impact on land use · **// Slope //** - breaks are the same as in landscape factors · **// Water Table //** - 3 water classes used reflect relative impact on use · **// Flooding //** - based on frequency of occurrence: frequent (1 year in 5), occasional (at least 1 year in 25), no flooding (occurs less than 1 year in 25) · Slow permeability makes it likely that wetness will be a problem · Houses should not be built on sites subject to flooding · The assumed depth of drain-field trenches is 24-28 inches · Disposal of human waste is a critical role that the soil must handle, soil in a drain-field must be able to dispose of water equivalent to 200 inches of rainfall a year, must be moderately permeable and deep to water/rock · Clays may seal and cause “drowning of tree roots” · Excessive slopes increase runoff and erosion and reduce water available for growth · Frequent flooding can damage shrubs and cause “drowning of tree roots” · Soil properties important for road-fill or fill of any kind relate to soil texture and thickness of suitable material · Materials that are too high in clay or sand are less desirable · A sufficient depth of suitable material above rock or a water table is needed for economic operation · The source area slope relates to the erosion hazard · Waste lagoons require a slowly permeable soil or one that can be made impermeable · Local clayey soil material can be used to line ponds and lagoons · Shallow depth to rock or water table reduces the depth of a lagoon pond and exposed rock may be hard to seal

Notes for: []

//__ Soils: __// · Soil= the collection of natural bodies on the earth’s surface, in places modified or even made by man of earthly materials, containing living matter and supporting or capable of supporting plants out-of-doors · Soil is both a product of nature and a critical part of natural systems · “begins” as parent material, weathering eventually causes a differentiation into distinct horizons · 5 soil-forming factors: climate, living organisms, topographic relief, parent material and time (CLORPT) · considered “young” “mature” or “old” depending on the extent of weathering and horizon development · NY soils are relatively young · Soil properties and limitations: composition, texture, structure, slope, color, chemistry, profile, permeability and drainage · The Soil Survey classifies soils into series for identification · Most soils in the US are aerobic · In soils where saturation w/ water is prolonged and is repeated for many years (hydric soils), unique soil properties usually develop · Hydric soils favor the formation of many types of wetlands and help identify wetlands · Soil erosion and sedimentation are separate but they occur together · To grow crops, 6 inches of topsoil are required · Soil-plant interactions: nutrient transfer, decomposition/organic matter, erosion prevention, fertility/productivity, soil a matrix/mechanical support · Soil-water interactions: filtration, eluviation/illuviation, holding capacity, erosion effects, wetlands including definition of hydric soils, water table, aquifer recharge · Soil forming factors: parent material, climate, plant/animal life, topography, time · Major soil properties and limitations: texture, structure, color, chemical content, slope, water content, permeability, mottling, consistence, aggregation, cation exchange capacity, pH   · Major components of soil: air, water, minerals, organic matter · Major soil types: sand, clay, loam · Particles: sand, silt, clay · Soil profile: differentiation of soil horizons · Soil quality indicators: aggregate stability, organic matter, crusts and infiltration · Soil resource concerns: compaction, erosion, sediment deposition Great job so far, Kim!

Chris: = D Soils

Soil Regimes

Dec-Jan types - Isohypothermic, Hyperthermic, Isothermic and Isomesic. Feb-Oct-Mar - types Thermic and Mesic. May-Sep - types Frigid and Isofrigid. June-August - types Cryic July-August - types Hypergelic, Pergelic and subgelic.

Species of organisms coexist and relate to one another. we can see living and nonliving coexits.

Tropic levels are levels of energy.

Micropores tend to be water filled. Driving vehicles across wet soil will compact the soil and destroy soil pore space. Definition of macropore.
 * Macropores** are cavities which are larger than 50 nm which may occur in various solids. In the [|soil], they created by such agents as [|plant] [|roots], soil cracks, or [|soil fauna]. Macropores increase the [|hydraulic conductivity] of the soil, allowing water to [|infiltrate] faster or for shallow [|groundwater] to flow faster.- wikipedia info.

**Erosion control is not enough**

Soil conservation policy in the United States stems from the devastating erosion events of the 1920s and ’30s. Out of concern for preserving agricultural productivity came the concept of tolerable soil loss and the creation of the T factor - the maximum annual soil loss that can occur on a particular soil while sustaining long-term agricultural productivity. Conservationists focused on reducing soil loss to T by applying practices, such as terraces, contour strips, grassed waterways, and residue management. By the end of the century, concerns about air and water quality became as important as concerns about agricultural productivity. To address these environmental goals and maintain the land’s productive potential, we must now go beyond erosion control and manage for soil quality. How soil functions on every inch of a farm–-not just in buffers or waterways–-affects erosion rates, agricultural productivity, air quality, and water quality. The most practical way to enhance soil quality today is to promote better management of soil organic matter or carbon. In short, we should go beyond T and manage for C (carbon).

Why focus on soil organic matter?

Many soil properties impact soil quality, but organic matter deserves special attention. It affects several critical soil functions, can be manipulated by land management practices, and is important

in most agricultural settings across the country. Because organic matter enhances water and nutrient holding capacity and improves soil structure, managing for soil carbon can enhance productivity and environmental quality, and can reduce the severity and costs of natural phenomena, such as drought, flood, and disease. In addition, increasing soil organic matter levels can reduce atmospheric CO2 levels that contribute to climate change.

Kim: __Hydric soils:__ · Information that was previously published in “Hydric Soils of the US” · Hydric soil = soil that is sufficiently wet in the upper part to develop anaerobic conditions during the growing season, soils that form under conditions of saturation, flooding or ponding · The criteria for hydric soils are selected soil properties that are documented in Soil Taxonomy · **Cannot** be used in the field to determine hydric soils · The purpose of the criteria is to generate a list of soil map unit components that are **likely** to meet the hydric soil definition · Caution must be used when comparing the list of hydric components to soil survey maps · Lists of hydric soils along with soil survey maps are good off-site ancillary tools to assist in wetland determinations, but they are not a substitute for observations made on-site · Field indicators of hydric soils are morphological properties known to be associated with soils that meet the definition of hydric · Field indicators are essential because once they are formed, they persist during wet and dry seasons · Field indicators are an efficient on-site means to confirm the presence of hydric soils, they are designed to identify soils that meet the definition without further data collection · The concept of hydric soils includes soils developed under sufficiently wet conditions to support the growth and regeneration of hydrophytic vegetation · Soils that are sufficiently wet because of artificial measures are included in the concept of hydric soils · The lists of hydric soils were created by using criteria that were developed by the __National Technical Committee for Hydric Soils__ · Hydric soil lists have a number of agricultural and non-agricultural applications including: assistance in land-use planning, conservation planning, and assessment of potential wildlife habitat · An area that meets the hydric soil criteria must also meet the hydrophytic vegetation and wetland hydrology criteria in order for it to be classified as a jurisdictional wetland · Criteria: all Histels except Folistels and Histosols except Folists or soils in Aquic suborders that are somewhat poorly drained or poorly drained with water tables equal to 0.5 ft from the surface during the growing season if permeability is equal to or greater than 6.0 in/hour, soils that are frequently ponded or flooded for long durations __Field Indicators of Hydric Soils in the US:__ · Indicators are not intended to replace or modify the requirements contained in the definition of a hydric soil. · changes and additions are likely to be made annually · order to properly use the Indicators, a basic knowledge of soil-landscape relationships and soil survey procedures is necessary · Indicators are designed to be regionally specific. The description of each indicator identifies the and resource regions (LRRs) or major land resource areas (MLRAs) in which the indicator can be used · Indicators are used to identify the hydric soils; however, some hydric soils that lack the currently listed indicators. Therefore, the lack of any listed indicator does not prevent classification of the soil as hydric. Such soils should be studied and their characteristic morphologies identified · Hydric soils are defined as soils that formed under conditions of saturation, flooding, or ponding long enough during the growing season to develop anaerobic conditions in the upper part · Saturation or inundation when combined with microbial activity in the soil causes a depletion of oxygen · promotes biogeochemical processes (the accumulation of organic matter and the reduction, translocation, and/or accumulation of iron/ other reducible elements  · indicators are formed predominantly by the accumulation or loss of iron, manganese, sulfur, or carbon compounds.   · The presence of hydrogen sulfide gas (which has rotten egg odor) is a strong indicator of a hydric soil, but occurs only on the wettest sites containing sulfur   · Some of these carbon accumulation features, such as Indicators A1 (Histosol or Histel), A2 (Histic Epipedon), and A3 (Black Histic), are often used to identify hydric soils   · Because they are maximum expressions of anaerobiosis, they are rarely used for delineation purposes   · There are hydric soils with morphologies that are difficult to interpret and hydric soils that seem inconsistent with the landscape, vegetation, or hydrology (includes those that formed in grayish or reddish parent materials; soils with high pHor a low content of organic matter; Mollisols and Vertisols; soils with relict redoximorphic features; and disturbed soils, such as cultivated soils and soils in filled areas) · The Indicators generally work best on the margins · Soils that are artificially drained or protected (for instance, by levees) are hydric if they meet the definition of hydric soils in their undisturbed state · Typically, contemporary and recent hydric soil features have diffuse boundaries; relict hydric soil features have sharp boundaries. · Where soil morphology seems inconsistent it may be necessary to obtain the assistance of an experienced scientist to determine whether the soil is hydric · To document a hydric soil: dig soil profile to a depth of approximately 50 cm, specify which of the Indicators have been met · Deeper examination of soil may be required where field Indicators are not readily apparent · It is always recommended that soils be excavated and described as deep as necessary · examination to less than 50 cm (20 inches) may suffice in soils with surface horizons of organic material or mucky mineral material because these shallow organic accumulations only occur in hydric soils · Conversely, depth of excavation will often be greater than 50 cm in Mollisols because their upper horizons commonly have no visible redoximorphic features because of the masking effect of organic material. · On many sites it is necessary to make exploratory observations to a meter or more · There are wetlands that do not have any of the approved hydric soil indicators in their wettest parts · users of the hydric soil indicators should concentrate their observation efforts at the wetland edge conditions are suspect · begin to look for an Indicator at the soil surface nationwide when applying indicators A1 and A2 and in LRRs F, G, H, and M if the material beneath any mucky peat and/or peat is sandy. · In LRRs R, W, X, and Y, we begin our observations at the top of the mineral surface (underneath any and all fibric, hemic, and/or sapric material), except for application of indicators A1 and A2  · in LRRs F, G, H, and M, if the material beneath any mucky peat and/or peat is not sandy, we begin our observations at the top of the muck or mineral surface except for application of indicators A1 and A2. · All colors refer to moist Munsell colors · Soil colors should not be rounded to qualify as meeting an indicator · Particular attention should be paid to changes in topography over short distances (microtopography) · Small changes in elevation may result in repetitive sequences of hydric/nonhydric soils and delineation of individual areas may be difficult · Often the dominant condition (hydric/nonhydric) is the only reliable interpretation · The shape of the local landform can greatly affect the movement of water · Significant changes in parent material can affect the hydrologic properties · “All soils” refers to soils with any USDA soil texture · Use the following Indicators regardless of texture: · **A1. Histosol** (for use in all LRRs) **or Histel** (for usein LRRs with permafrost). Classifies as a Histosol (except Folist) or as a Histel (except Folistel) · Organic soil materials include muck (sapric soil material), mucky peat (hemic soil material), and peat (fibric soil material) · **A2. Histic Epipedon.** For use in all LRRs. A histic epipedon underlain by mineral soil material with chroma of 2 or less · Aquic conditions or artificial drainage are required · **A3. Black Histic.** For use in all LRRs. A layer of peat, mucky peat, or muck 20 cm or more thick that starts within the upper 15 cm of the soil surface; has hue of 10YR or yellower, value of 3 or less, and chroma of 1 or less; and is underlain by mineral soil material with chroma of 2 or less · does not require proof of aquic conditions or artificial drainage · **A4. Hydrogen Sulfide.** For use in all LRRs. A hydrogen sulfide odor within 30 cm of the soil surface (“rotten egg smell”) indicates that sulfate-sulfur has been reduced and the soil is anaerobic. In most hydric soils, the sulfidic odor occurs only when the soil is saturated and anaerobic. · **A5. Stratified Layers.** For use in LRRs C, F, K, L, M, N, O, P, R, S, T, and U; for testing in LRRs V and Z. Several stratified layers starting within the upper 15cm of the soil surface. One or more of the layers has value of 3 or less with chroma of 1 or less, and/or it is muck, mucky peat, or peat or has a mucky modified mineral texture · Use of this indicator may require assistance from a trained soil scientist · The minimum organic carbon content of at least one layer is slightly less than is required for indicator A7 (5 cm Mucky Mineral); at least 70 percent of the soil material is covered, coated, or similarly masked with organic matter. An undisturbed sample must be observed · Many alluvial soils have strata at greater depths; these are not hydric soils. Many alluvial soils have strata at the required depths but do not have chroma of 2 or less; these do not meet the requirements for this indicator. · The Stratified Layers indicator occurs in any type soil material · **A6. Organic Bodies.** For use in LRRs P, T, U, and Z. Presence of 2% or more organic bodies of muck or a mucky modified mineral texture, approximately 1 to 3 cm in diameter, starting within 15 cm of the soil surface · The concentration of organic carbon in organic bodies is the same as in the Muck or Mucky Texture Indicators. · The Organic Bodies indicator includes the indicator previously named “accretions” · Many organic bodies lack the required amount of organic carbon and are not indicative of hydric soils · Organic bodies of hemic material (mucky peat) and/or fibric material (peat) do not meet the requirements of this indicator, nor does material consisting of partially decomposed root tissue Her HeHHere is the list of sites, please put your name next to the ones that you know. If you know only a certain number of pages from a site, list those pages:

Resources Soils: http://soils.usda.gov/ Kim http://www.swcs.org/ http://www.blm.gov/nstc/soil/index.html http://soil.gsfc.nasa.gov/ http://soils.usda.gov/use/urban/downloads/primer(screen).pdf http://websoilsurvey.nrcs.usda.gov/app/ http://soildatamart.nrcs.usda.gov/ http://www.nysenvirothon.net/4H_soilhandbook97_1_.pdf Kim http://www.nysenvirothon.net/FieldIndicators_v6_0.pdf Kim http://www.nysenvirothon.net/FromTheSurfaceDown_1_.pdf http://www.nysenvirothon.net/Hydric_Soils.pdf Kim http://www.nysenvirothon.net/Master_Horizons_and_Layers.pdf Kim http://www.nysenvirothon.net/primer_screen_.pdf http://www.nysenvirothon.net/Soil_Organic_Matter.pdf http://www.nysenvirothon.net/Soils_Study_Guide.pdf Kim

**SOILS/LAND USE **

**OUTLINE **

I. Soil: What is it?

A. Definition B. Development

1) parent material  2) processes of development

II. Characteristics

A. Composition B. Texture C. Structure D. Slope E. Color F. Chemistry <span style="color: black; font-family: 'Helvetica','sans-serif'; font-size: 9.5pt;">G. Horizons/Profile <span style="color: black; font-family: 'Helvetica','sans-serif'; font-size: 9.5pt;">H. Permeability/Percolation <span style="color: black; font-family: 'Helvetica','sans-serif'; font-size: 9.5pt;">I. Soil Water and Drainage

<span style="color: black; font-family: 'Helvetica','sans-serif'; font-size: 9.5pt;">III. Soil Maps (Know how to use this information)

<span style="color: black; font-family: 'Helvetica','sans-serif'; font-size: 9.5pt;">A. Soil Series <span style="color: black; font-family: 'Helvetica','sans-serif'; font-size: 9.5pt;">B. Map Symbols <span style="color: black; font-family: 'Helvetica','sans-serif'; font-size: 9.5pt;">C. Slope Classes <span style="color: black; font-family: 'Helvetica','sans-serif'; font-size: 9.5pt;">D. Soil Surveys

<span style="color: black; font-family: 'Helvetica','sans-serif'; font-size: 9.5pt;">1) what are they  <span style="color: black; font-family: 'Helvetica','sans-serif'; font-size: 9.5pt;">2) how to use them

<span style="color: black; font-family: 'Helvetica','sans-serif'; font-size: 9.5pt;">IV. Soil Interpretations (Know how to use this information)

<span style="color: black; font-family: 'Helvetica','sans-serif'; font-size: 9.5pt;">A. Agriculture <span style="color: black; font-family: 'Helvetica','sans-serif'; font-size: 9.5pt;">B. Forestry <span style="color: black; font-family: 'Helvetica','sans-serif'; font-size: 9.5pt;">D. USDA Land Use Classification

<span style="color: black; font-family: 'Helvetica','sans-serif'; font-size: 9.5pt;">1) prime soils

<span style="color: black; font-family: 'Helvetica','sans-serif'; font-size: 9.5pt;">V. Erosion & Sedimentation

<span style="color: black; font-family: 'Helvetica','sans-serif'; font-size: 9.5pt;">A. Definitions <span style="color: black; font-family: 'Helvetica','sans-serif'; font-size: 9.5pt;">B. Types of erosion <span style="color: black; font-family: 'Helvetica','sans-serif'; font-size: 9.5pt;">C. Economic impacts <span style="color: black; font-family: 'Helvetica','sans-serif'; font-size: 9.5pt;">D. Prevention

<span style="color: black; font-family: 'Helvetica','sans-serif'; font-size: 9.5pt;">1) principles  <span style="color: black; font-family: 'Helvetica','sans-serif'; font-size: 9.5pt;">2) agricultural conservation practices <span style="color: black; font-family: 'Helvetica','sans-serif'; font-size: 9.5pt;">3) nonagricultural conservation practices

<span style="color: black; font-family: 'Helvetica','sans-serif'; font-size: 9.5pt;">VI. Hydric Soils

<span style="color: black; font-family: 'Helvetica','sans-serif'; font-size: 9.5pt;">A. Definition <span style="color: black; font-family: 'Helvetica','sans-serif'; font-size: 9.5pt;">B. Characteristics <span style="color: black; font-family: 'Helvetica','sans-serif'; font-size: 9.5pt;">C. Uses/Limitations <span style="color: black; font-family: 'Helvetica','sans-serif'; font-size: 9.5pt;">D. Economic Value

<span style="color: black; font-family: 'Helvetica','sans-serif'; font-size: 9.5pt;">. SOIL CONCEPTS

<span style="color: black; font-family: 'Helvetica','sans-serif'; font-size: 9.5pt;">A. Definition of soil -- There can be many uses of the word "soil", depending upon the context. For example, soil can be thought of as an engineering material for road construction, as dirt on clothing, as a mixture of ingredients for growing potted plants, or what the farmers plow every spring. For the purposes of the Envirothon, "soil" is defined as it is in the textbook (Soil Science Simplified, 1997): "Soil is the collection of natural bodies on the earth's surface, in places modified or even made by man of earthy materials, containing living matter and supporting or capable of supporting plants out-of-doors." Soil is thus considered both a product of nature and a critical part of natural systems. This definition also allows soils to be collectively grouped into a classification system, as used in making soil surveys.

<span style="color: black; font-family: 'Helvetica','sans-serif'; font-size: 9.5pt;">B. Soil development -- a process that occurs over time.

<span style="color: black; font-family: 'Helvetica','sans-serif'; font-size: 9.5pt;">1. Soils "begin" as parent material, then the process of weathering occurs. <span style="color: black; font-family: 'Helvetica','sans-serif'; font-size: 9.5pt;">2. Weathering eventually causes a differentiation into distinct horizons. <span style="color: black; font-family: 'Helvetica','sans-serif'; font-size: 9.5pt;">3. A soil and its profile show the effects of five soil-forming factors: Climate, Living Organisms, Topographic Relief, Parent material and Time (it may help to remember the word "CLORPT"). Soils can be considered as "young", "mature" or "old", depending upon their extent of weathering and horizon development. Soils in NY State are relatively young or mature, but not old -- their parent material was exposed or deposited during the relatively recent retreat of glaciers, some 10 to 15 thousand years ago.

<span style="color: black; font-family: 'Helvetica','sans-serif'; font-size: 9.5pt;">II. SOIL CHARACTERISTICS

<span style="color: black; font-family: 'Helvetica','sans-serif'; font-size: 9.5pt;">A. Composition -- About a 50%-50% mix of solids and open space; voids may hold water or air.

<span style="color: black; font-family: 'Helvetica','sans-serif'; font-size: 9.5pt;">B. Texture -- refers to soil particle size, sand = 2 to 0.05 mm; silt = 0.05 to 0.002 mm; clay = <0.002 mm. Soil texture influences water storage & movement, fertility, and workability or "tilth". c "Loam" is a name for one of various mixtures of these three particle sizes.

<span style="color: black; font-family: 'Helvetica','sans-serif'; font-size: 9.5pt;">C. Structure -- the arrangement of soil particles into aggregates, which may have various shapes, sizes and degrees of development or expression. Soil structure influences aeration, water movement, erosion resistance, and root penetration.

<span style="color: black; font-family: 'Helvetica','sans-serif'; font-size: 9.5pt;">D. Slope -- the inclination of the ground surface. Slope influences runoff of rainfall, soil erosion, stability, and machinery operation.

<span style="color: black; font-family: 'Helvetica','sans-serif'; font-size: 9.5pt;">E. Color -- Soil color often indicates soil moisture status and is used for determining hydric soils. Often described using general terms, such as dark brown, yellowish brown, etc., soil colors are also described more technically by using Munsell soil color charts, which separate color into components of hue (relation to red, yellow and blue), value (lightness or darkness) and chroma (paleness or strength).

<span style="color: black; font-family: 'Helvetica','sans-serif'; font-size: 9.5pt;">F. Chemistry -- A complex subject within soil science; the most important subjects are:

<span style="color: black; font-family: 'Helvetica','sans-serif'; font-size: 9.5pt;">pH -- The acidity or alkalinity of soils, which affects plant growth and soil fertility.

<span style="color: black; font-family: 'Helvetica','sans-serif'; font-size: 9.5pt;">G. The soil profile -- A vertical cut that exposes soil layering or horizons. Horizons are formed by combined biological, chemical and physical alterations. A, B, and C symbols are used to describe the topsoil, subsoil and substratum, respectively.

<span style="color: black; font-family: 'Helvetica','sans-serif'; font-size: 9.5pt;">H. Permeability -- The ability of a soil to transmit water or air. Faster or greater permeability often occurs in sandy or gravelly soils due to large pore spaces. Slower permeability typically occurs in finer textured clay soils, or compacted soils with little structure.

<span style="color: black; font-family: 'Helvetica','sans-serif'; font-size: 9.5pt;">I. Drainage -- The rate in which water is removed from a soil. Drainage influences most uses of soils, whether for agriculture, silviculture or urban. Classes of soil drainage are those found in soil survey reports, such as well drained, moderately well drained, somewhat poorly drained, poorly drained, and very poorly drained. Soil color patterns (such as mottle patterns or redoximorphic features) often indicate soil drainage class. Most productive agricultural soils in NY are well drained or moderately well drained. By contrast, hydric soils are poorly or very poorly drained. A soil's natural drainage rate can be significantly increased by subsurface "tile" drainage.

<span style="color: black; font-family: 'Helvetica','sans-serif'; font-size: 9.5pt;">III. SOIL SURVEY MAPS

<span style="color: black; font-family: 'Helvetica','sans-serif'; font-size: 9.5pt;">A. Soil Series -- A level of Soil Taxonomy, the soil classification system used in making soil surveys. One example is the "Mardin Series".

<span style="color: black; font-family: 'Helvetica','sans-serif'; font-size: 9.5pt;">IV. SOIL SURVEY INTERPRETATIONS

<span style="color: black; font-family: 'Helvetica','sans-serif'; font-size: 9.5pt;">Become familiar with the interpretive tables within a relatively modern soil survey (since about 1970). These commonly include soil suitability for uses such as: <span style="color: black; font-family: 'Helvetica','sans-serif'; font-size: 9.5pt;">A. Agriculture

<span style="color: black; font-family: 'Helvetica','sans-serif'; font-size: 9.5pt;">V. EROSION AND SEDIMENTATION

<span style="color: black; font-family: 'Helvetica','sans-serif'; font-size: 9.5pt;">These are separate processes, but think of them as occurring together, since once soil is eroded it will eventually become sediment somewhere. <span style="color: black; font-family: 'Helvetica','sans-serif'; font-size: 9.5pt;">A. Erosion is the "wearing away" of land by the action of water, wind or ice. It is a natural, geologic process, but often is greatly accelerated by man's activities.

<span style="color: black; font-family: 'Helvetica','sans-serif'; font-size: 9.5pt;">VI. HYDRIC SOILS

<span style="color: black; font-family: 'Helvetica','sans-serif'; font-size: 9.5pt;">A. Introduction <span style="color: black; font-family: 'Helvetica','sans-serif'; font-size: 9.5pt;">Most of the soils in the U.S. are aerobic. This is important to our food, fiber and forest production because plant roots respire (that is, they consume oxygen and carbohydrates while releasing CO2) and there must be sufficient air -- especially oxygen -- in the soil to support root life. As mentioned in the textbook (Soil Science Simplified), air normally moves through interconnected pores by forces such as changes in atmospheric pressure, turbulent wind, the flushing action of rainwater, and by simple diffusion.

<span style="color: black; font-family: 'Helvetica','sans-serif'; font-size: 9.5pt;">In addition to plant roots, most forms of soil microorganisms need oxygen to survive. This is true of the more well-known soil animals as well, such as ants, earthworms and moles. But soils can often become saturated with water due to rainfall and flooding. Air travels very slowly (some 10,000 times slower) when soil becomes saturated with water because there are no open passageways for air to travel. When oxygen levels become limited, intense competition arises between soil life forms for the remaining oxygen. When this anaerobic (no oxygen) environment continues for long periods during the growing season (April to October in most of NY), quite different biological and chemical reactions begin to dominate, compared with aerobic soils. In soils where saturation with water is prolonged and is repeated for many years, unique soil properties usually develop that can be recognized in the field. Soils with these unique properties are called Hydric Soils, and although they may occupy a relatively small portion of the landscape, they maintain important functions in the environment.

<span style="color: black; font-family: 'Helvetica','sans-serif'; font-size: 9.5pt;">B. Why are hydric soils important? <span style="color: black; font-family: 'Helvetica','sans-serif'; font-size: 9.5pt;">The environmental conditions that create hydric soils (water remaining at or near the soil surface for extended time periods during the growing season) also favor the formation of many types of wetlands.

<span style="color: black; font-family: 'Helvetica','sans-serif'; font-size: 9.5pt;">Wetlands play important roles in the environment, some of which we have only begun to understand and appreciate. Groundwater is recharged or restored by entering some wetlands; however, in New York soils it is probably just as common that groundwater discharges (exits) to become surface water through wetlands. During periods of heavy rains or melting snow, flooding can present a real danger to people and property; but because wetlands occupy depressions in the landscape they can trap and thereby detain flood waters, thus reducing downstream damages. Wetlands are often difficult places for humans to physically move around in, so most people avoid them; this is one reason that they provide critical habitat for many rare and endangered species of flora and fauna. Because wetlands often occur in relatively low elevations, they commonly receive polluted waters from man's activities on higher, drier ground; wetlands can effectively filter these waters and retain excess nutrients. Wetlands are also valuable for recreation, including nature appreciation, hunting, fishing, canoeing, etc.

<span style="color: black; font-family: 'Helvetica','sans-serif'; font-size: 9.5pt;">Due to historical and present development pressures, the number and extent of wetlands has been greatly diminished (by about 50%!) in the United States since the time when the first white settlers arrived. Within the last 10 to 20 years, political debates and new regulations have focused on methods to conserve and rehabilitate wetlands. Because they are formed in association with wetlands, hydric soils can be used to identify the presence and boundaries of wetlands. In fact, hydric soils were defined so that they help identify wetlands. Along with unique vegetation and hydrology, hydric soils are one of the three required indicators for wetland identification. As a result, hydric soils are a very important issue in land management and land planning across the United States due to their role in the identification of wetlands and their function in wetland ecology.

<span style="color: black; font-family: 'Helvetica','sans-serif'; font-size: 9.5pt;">C. Defining hydric soils <span style="color: black; font-family: 'Helvetica','sans-serif'; font-size: 9.5pt;">Various government agencies are involved with wetland protection. The NY State Department of Environmental Conservation (DEC) protects wetlands over 5 hectares (12.4 acres) in size. The US Department of Agriculture - Natural Resources Conservation Service identifies and protects wetlands that have been used for agriculture. The US Army Corps of Engineers protects wetlands of practically any size. With the help of soil scientists, they have defined hydric soils, which they consider to be those soils which are developed under sufficiently wet conditions to support the growth and regeneration of hydrophytic vegetation:

<span style="color: black; font-family: 'Helvetica','sans-serif'; font-size: 9.5pt;">A hydric soil is a soil that is saturated, flooded, or ponded long enough during the growing season to develop anaerobic conditions in the upper part.

<span style="color: black; font-family: 'Helvetica','sans-serif'; font-size: 9.5pt;">This definition can be broken up into three component parts:

<span style="color: black; font-family: 'Helvetica','sans-serif'; font-size: 9.5pt;">1) The soil is saturated, flooded or ponded. Saturated conditions are often the result of a high water table. Flooded conditions are produced by overflowing streams, runoff from higher surrounding slopes or from high tides that inundate coastal wetlands. Ponded conditions are produced by higher water inflow than water outflow from a closed depression.

<span style="color: black; font-family: 'Helvetica','sans-serif'; font-size: 9.5pt;">2) Wet conditions occur during the growing season. This is the period of time when the soil is above 5oC or approximately 40oF. Above this temperature, biological activity is significant and many plants are able to grow.  <span style="color: black; font-family: 'Helvetica','sans-serif'; font-size: 9.5pt;">3) The soil is wet long enough to develop anaerobic conditions in the upper part. The vast majority of soil biological activity occurs at or near the soil surface. When the soil is biologically active, a few weeks of wet conditions is usually adequate to use up available oxygen; however, this can be affected by many factors (e.g. soil and water temperature, the oxygen content of the water, soil organic matter content, soil permeability, etc.). The important thing is that anaerobic conditions result often or long enough to support mostly hydrophytic (water-loving) plants. Further, much of the biological activity in soils is engaged in the decomposition of organic matter either deposited within or on the soil surface. When oxygen is not available to the soil flora and fauna, biological activity is greatly reduced. As a result, organic material builds up in the soil. Additionally as a result of the wet, anaerobic environment the soil takes on a characteristic reducing condition and undergoes chemical reactions that are different than non-hydric soils.

<span style="color: black; font-family: 'Helvetica','sans-serif'; font-size: 9.5pt;">D. Hydric soil properties and indicators <span style="color: black; font-family: 'Helvetica','sans-serif'; font-size: 9.5pt;">The physical, chemical and biological properties which make hydric soils recognizable are the result of complex bio-geochemical processes occurring over many years.

<span style="color: black; font-family: 'Helvetica','sans-serif'; font-size: 9.5pt;">Hydric soils usually have a water table, or the top of a zone of saturation, within one foot from the soil surface during the growing season. This shallow water table excludes oxygen and so creates a reducing environment, especially in the upper part of the soil profile. As a result, mostly hydrophytic plants proliferate -- such as rushes, cattails, sedges and skunk cabbage.

<span style="color: black; font-family: 'Helvetica','sans-serif'; font-size: 9.5pt;">Most soils, including hydric soils, are dominantly composed of minerals such as quartz, feldspars, clay minerals, etc. However, hydric soils commonly have a build-up of organic matter at the soil surface, for reasons described above, which can make the surface horizon dark colored. If the organic matter content (measured as organic carbon) is greater than 20 to 30% of the soil's weight (depending upon clay content) and this organic-rich layer is over 16 inches thick, then it is considered an organic soil. Most soil organic matter originates as plant tissue, so organic soils are called Histosols (the Greek word for tissue is histose). Many types of organic soils exist, but they can be classified by their thickness and degree of decomposition (see chapter 12 of text). Peat, such as common "peat moss", is mostly composed of recognizable plant fragments that are only partly decomposed. Muck contains highly decomposed organic matter and, when drained of excess water and carefully managed, these black and spongy soils comprise some of the most important vegetable-producing soils in the eastern US. <span style="color: black; font-family: 'Helvetica','sans-serif'; font-size: 9.5pt;">Another property unique to hydric soils is their color or color patterns. Besides the dark shading from the presence of organic matter, iron compounds are the most important coloring agents in soils. Hydric soils tend to exhibit gray or blue-gray colors (known as gleying or gleyed colors) especially just beneath the topsoil or surface horizon (see lower portion of photograph). This results from the chemically reduced oxidation state of iron compounds, as opposed to the rusty red (oxidized) and brown colors of drier, non-hydric soils. Where shallow water tables fluctuate, gray, yellow and red colors can also occur as small splotches, threadlike or network patterns, created by accumulations or depletions of iron and manganese (orange colors in photograph). Because they result from processes of reduction and oxidation these color indicators of wetness are collectively termed redoximorphic features.

<span style="color: black; font-family: 'Helvetica','sans-serif'; font-size: 9.5pt;">Hydric Soils section written by Larry Day (Delaware County Soil and Water Conservation District) and Jonathan Russell-Anelli (c/o Dept. Soils, Crops and Atmospheric Sciences, Cornell University).