Soils Somewhat Simplified

• Its NOT DIRT!!!

Soils Somewhat Simplified

• SOILS FORM IN MINERAL AND ORGANIC DEPOSITS

• OVER THOUSANDS TO MILLIONS OF YEARS• NEW ENGLAND SOILS ARE YOUNGLESS THAN

15OOO YEARS OLD (AFTER THE LAST GLACIATION)


• 12 “GREAT GROUPS”OF SOILS IN THE WORLD• 4 FOUND IN NH• ENTISOLS• INCEPTISOLS• SPODOSOLS• HISTOSOLS


• SOILS CONSIST OF FOUR CONSTITUENTS• MINERAL• ORGANIC • WATER • AIR• IN VARYING AMOUNTS


• NRCS (OLD SCS) HAS NAMED MANY “SOIL SERIES” BASED ON PROPERTIES

• NOW NUMERIC IN NEWER VERSIONS• OFTEN ASSOCIATED IN COMPLEXES• SOIL CATENAS ARE SIMILAR SOILS IN

DIFFERENT DRAINAGE CLASSES


• LIMIT OF MAPPING IS ABOUT FIVE ACRES• MOST MAPPED UNITS WILL HAVE SOME OR

MANY INCLUSIONS OF OTHER SOILS


• SOILS FORM IN PARENT MATERIALS WITH VARYING CHARACTERISTICS

• WHICH WILL STRONGLY INFLUENCE THE DEVELOPED SOIL

• COARSER, FINER, MORE OR LESS COMPACT


• FOUR SOIL FORMING PROCESSES• ADDITIONS• TRANSFORMATIONS• TRANSLOCATIONS• LOSSES


• ADDITIONS MAY INCLUDE FERTILIZERS, POLLUTANTS, WIND AND WATER MOVED MATERIALS


• TRANSFORMATIONS ARE CHANGES THAT TAKE PLACE WITHOUT MOVING MATERIALS-”IN SITU”

• BY WEATHERING, BIOLOGIC ACTION, FROST, ETC


• TRANSLOCATIONS MOVE MATERIALS DOWN, OR SIDEWAYS OR UP, SOMETIMES LEAVING THE SOIL

• WATER MOVES SOLUBLE SALTS, CLAYS, ORGANICS, CHEMICALS DOWN OR SIDEWAYS

• AND SOMETIMES UP


• LOSSES COME FROM WATER MOVEMENT• MAJOR LOSSES FROM EROSION OR WIND• MAY RESULT IN ADDITIONS ELSEWHERE


• SOILS HAVE DIMENSION- HORIZONTAL AND VERTICAL

• AND ARE SURROUNDED BY OTHER SOILS WITH DIFFERENT PROPERTIES


• SOILS HAVE DISTINCT LAYERS CALLED “HORIZONS”

• “O” FOR ORGANIC• ABOVE THE MINERAL HORIZON• DECOMPOSING MATERIALS


• A-TOPSOIL • FIRST MINERAL HORIZON• DARK DUE ORGANIC MATERIAL• AND LOSS OF IRON AND OTHER COMPOUNDS• THIN IN FORESTED AREAS • THICKER WHERE PLOWED “Ap”


• E HORIZON SOMETIMES FOUND- GRAY DUE TO LOSS OF IRON, ALUMINUM AND CLAY

• “ELUVIATED” DOWNWARDS• “ALBIC” HORIZON”


• B OR SUBSOIL COLORED BY IRON AND OTHER MATERIALS “ILLUVIATED” FROM ABOVE

• WEATHERED BY WATER, FROST, ROOTS, BOILOGIC ACTIVITY


• C IS SUBSTRATUM, LESS AFFECTED BY WEATHERING- “PARENT MATERIAL”


• R IS ROCK• SOMETIIMES WEATHERED INTO SAPROLITE-

NOT REALLY SOIL


• SOILS HAVE PROPERTIES• TEXTURE• STRUCTURE• CONSISTENCE• COLOR


• TEXTURE IS COARSENESS-FINENESS• PROPORTIONS OF SAND, SILT, CLAY• SAND IS >0.05 MM, >2.0 MM• SILT IS > 0.002MM• NAMES INCLUDE SAND, LOAM, SILT LOAM,THE

COMMON “FINE SAND LOAM”• CLAY IS RARE


• STRUCTURE IS THE WAY SOIL PARTICLES OR “PEDS” ARE ARRANGED

• GRANULAR, PLATY, BLOCKY, MASSIVE• IN SANDY SOILS, SINGLE GRAIN


• WATER MOVES THROUGH STRUCTURAL CRACKS, ROOT CHANNELS

• OR AROUND SAND GRAINS• BY ADHESION OR BY GRAVITY


• CONSISTENCE IS THE FIRMNESS OF THE SOIOL PEDS OR MASSES


• COLOR IS USUALLY FROM THE COATINGS OF IRON, ALUMINUM AND CLAY

• MOST MINERALS IN NH GRAY• COLOR CHANGES DUE TO SOIL FORMING,

WETNESS, BOILOGIC ACTIVITY, TRANSLOCATION


• COLORS ARE THE PROPERTIES THAT GUIDE US TO MANY INFERENCES ABOUT SOIL CONDITIONS

• PARTICULARLY WETNESS


• SEASONAL HIGH WATER TABLE IS A CONCEPT• NOT THE HIGHEST OBSERVED EVENT• BUT AN AVERAGE OVER TIME• DURING THE GROWING SEASON


• IRON AND COLORING AGENTS THAT COAT THE SOIL

• ARE CHANGED DURING WET TIMES • BY BIOACTIVITY• BECOME “REDUCED” AND CAN DISSOLVE• THEY TRANSLOCATE


• IRON OXIDIZES WHEN SOIL DRIES• GRAY PATCHES ARE LEFT

BEHIND-”DEPLETIONS”• IRON DEPOSITS ARE CALLED

ACCUMULATIONS• THESE APPEAR AS “MOTTLES”• AGAINST THE “MATRIX” COLOR


• THE MODERN TERM IS “REDOXIMORPHIC” FEATURES

• WHICH REFERS TO THE REDUCTION AND OXIDATION THAT DRIVES THE PROCESS

• REDOX FEATURES ARE DUE TO WETNESS• EXCLUDES OTHER PROCESSES THAT MAY

PRODUCE COLOR DIFFERENCES


• DRAINAGE CLASSES RUN FROM EXCESSIVELY WELL DRAINED TO VERY POORLY DRAINED


• POORLY AND VERY POORLY DRAINED ARE THE “HYDRIC” SOILS

• ONE OF THREE PARAMETERS FOR DETERMINING WETLAND STATUS

• ALONG WITH HYDROPITIC PLANTS AND HYDROLOGY


• URBAN SOILS ARE OFTEN VERY ALTERED• COMPACTED, MOVED, ADDED, ERODED• PROPRETIES TAKE SOME TIME TO FORM• COLOR USUALLY COMES FIRST, AND MAY

FORM QUICKLY


• THANKS!!!


Soils Somewhat Simplified

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