AEN 513 Soil Dynamics in Tillage and Traction

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AEN 513 Soil Dynamics in Tillage and Traction

BAE 513 Soil Dynamics in Tillage and Traction

Instructor:

Dr. Larry G. Wells

219 C.E. Barnhart Bldg.

Phone: 257-7300 ext 219

lwells@bae.uky.edu

A study of the principles which describe

dynamic soil-machine interaction. Physical and

mechanical properties are presented from two

perspectives: a) soils as media for plant growth,

and b) soils as media for mechanical

manipulation. An overview of traction and

tillage systems is presented as well as

relationships which characterize dynamic soilmachine

interaction in tillage and traction

processes.

1


COURSE OBJECTIVES

• To present an overview of tillage and traction devices

and systems.

• To present fundamental concepts describing dynamic

soil behavior in response to mechanical elements.

• To present methods for designing tillage systems which

produce a specified or desired soil state.

• To present methods of designing traction/transport

systems which meet specified performance

requirements with predictable and acceptable

alteration of affected soil profiles.

EVALUATION

• HOMEWORK 30%

Assigned approximately biweekly and

due one week after assigned

• LABORATORIES 30%

A total of six laboratories will be

conducted with written reports

• EXAMINATIONS 40%

Midterm and End-of-term examinations,

open notes

2


HISTORY OF TILLAGE

Tillage is the mechanical manipulation of soil for

the purpose of enhancing the growth of crops

• Archaeologists have found

wooden plows used in the

Euphrates and Nile valleys as

early as 3000 B.C. These

early great civilizations arose

because agriculture freed

humans to pursue activities

other than finding food.

• Iron plows were

simultaneously being used in

the Roman Empire and in

China around the time of

Christ (2000 years ago).

3


PRECURSORS TO MODERN TILLAGE TOOLS

• Moldboard plows were

introduced in Europe to

invert soil and make true

furrows around 1500 A.D.

• The Rotherham plow

developed in northern Europe

in the 1700’s.

• Jethro Tull developed the

concept of row crop

cultivation in the 1700’s.

• Robert Ransome patented the

first cast iron plow share and

replacable parts for tillage

implements by the early

1800’s

TILLAGE IN EXPANDING AMERICA

• Thomas Jefferson wrote a mathematical description of

the moldboard plow surface in the early 1800’s

• Illinois blacksmith John Deere developed and sold the

first steel plow with one piece share and moldboard in

the 1830’s

• The productive soils of the Midwest and Great Plains

were brought under cultivation during the 1800’s

4


TILLAGE IN EXPANDING AMERICA

• Steam power replaces

animal power in the

1860’s

• The internal combustion

engine replaces steam in

the early 1900’s

AGRICULTURAL PRODUCTION AND THE

INDUSTRIAL REVOLUTION IN THE U.S.

• The application of mechanical power

to agriculture transformed the U.S.

from an agrarian to an urban society

during the 1900’s

• Adverse consequences of extensive

tillage resulted in soil erosion,

dramatized by the Great Dustbowl of

the 1920’s

• In the 1950’s, a new (“notill”) row

crop production methodology

emerged using herbicides to control

weeds and planting crops in killed

sod.

• Other conservation tillage systems

have emerged which utilize crop

residue as surface mulch.

5


OVERVIEW OF TILLAGE TOOLS

Tillage is the mechanical manipulation of soil to

achieve an improved environment for seed

germination, root propagation, water

transmission and storage as well as facilitating

the control weeds.

REASONS FOR TILLAGE

• Break soil into small particles to enhance soil-seed contact

• Control weed growth

• Increase soil porosity and reduce its strength to facilitate

penetration by crop roots plus movement and storage of water

• Breaking up surface crusting or sealing to increase water

infiltration

• Increase porosity for improved aeration

• Improve drainage from rooting zone

• Incorporate residue of surface vegetation into the rooting zone

• Form soil for enhanced crop growth

• Mix soil horizons near the surface

• Loosen soil and disturb roots to facilitate harvesting of crops

6


• PRIMARY TILLAGE

.... the disturbance and loosening of soil which is

characterized by strong cohesion or attraction of soil

particles (depth ~ 15 to 90 cm)

• SECONDARY TILLAGE

.... the breakdown of large clusters or aggregates of

soil particles to facilitate seed-soil contact for

germination

(depth ~ 8 to 15 cm)

• ROW CROP CULTIVATION

.... shallow tillage between crop rows to control weeds

and manage moisture

• MOLDBOARD

PLOW

– Fragmenting soil

layers

– Inverting soil layers

and incorporation of

vegetation or its

residue

– Relatively high power

requirement

– Depth ~ 20 to 30 cm

PRIMARY TILLAGE

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PRIMARY TILLAGE

• DISK PLOW

– Performs similar

functions of moldboard in

soils that are extremely

cohesive or strong

• CHISEL PLOWS

– Depth ~ 10 to 15 cm

Soil loosened as prelude to

planting while leaving

surface covered with

residue of previous crop

– Comprises “conservation”

tillage systems

PRIMARY TILLAGE

8


• STUBBLE MULCH

TILLERS

– Depth ~ 15 to 20 cm

– Extensive loosening of

rooting zone with minimal

disturbance of the surface

PRIMARY TILLAGE

• DISK TILLERS

– Depth ~ 10 to 20 cm

– Used in tough prairie sods

– Often in tandem with

planter

PRIMARY TILLAGE

9


• MULCH-TILLERS

– Shallow version of chisel

plow

– Depth ~ 5 ot 10 cm

PRIMARY TILLAGE

• ROTARY TILLERS

– Depth ~ 10 to 15 cm

– Powered by tractor PTO

– High power requirement

– Aggressive pulverization

of soil

– Complete incorporation

and mixing of surface

vegetation

– Potential destruction of

soil structure

PRIMARY TILLAGE

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• LISTERS AND

BEDDERS

– Forming soil for special

crop environmental

requirements (beds or

furrows)

PRIMARY TILLAGE

• SUBSOILERS

– High power requirement

– Depth ~ 25 to 60 cm

– Used to remediate adverse

conditions in the rooting

zone caused by machinery

traffic or natural

phenomena

PRIMARY TILLAGE

11


SECONDARY TILLAGE

• DISK HARROWS

– Most common type

– Used to reduce size of soil

aggregates for improved

seed-soil contact and

germination

– Depth ~ 10 to 15 cm

SECONDARY TILLAGE

• ROLLER

COMPACTORS

– Used to break down soil

aggregates or clods which

are not affected by

harrows

– Provides firming of a

shallow layer near the

surface

12


SECONDARY TILLAGE

• TOOTHED HARROWS

– Various types

– Primarily used to break

up crust which may form

after primary tillage prior

to planting

SECONDARY TILLAGE

• FIELD CULTIVATORS

– Similar to chisel plows

and mulch tillers

– Deeper tillage than with

toothed harrows

13


SECONDARY TILLAGE

• ROTARY HOES

– High-speed, shallow

tillage especially effective

in destroying small weeds

– Can be used for both

secondary tillage and row

crop cultivation

ROW CROP CULTIVATION

• SHOVEL

CULTIVATORS

– Primarily used for weed

control

– Depth ~ 10 to 15 cm

– Can be used to break up

surface crusting which

may inhibit infiltration of

water

14


BAE 513 Soil Dynamics in Tillage and Traction

OVERVIEW OF TRACTION AND

TRANSPORT DEVICES

PRIMARY FUNCTIONS OF OFF-ROAD

TRACTION AND TRANSPORT DEVICES

• PROVIDE VERTICAL SUPPORT OR

FLOATATION FOR THE VEHICLE

• PROVIDE SUFFICIENT TRACTION OR THRUST

TO OVERCOME ALL RESISTANCE TO MOTION

ON THE TERRAIN

SECONDARY FUNCTIONS

– Braking, Steering, Climbing Obstacles, Absorbing Shock

15


VARIOUS TYPES OF

TRACTION/TRANSPORT DEVICES

CHORD CONSTRUCTION IN PNEUMATIC TIRES

16


TYPES AND SIZES OF PNEUMATIC TIRES

PNEUMATIC TIRE

TERMINOLOGY

17


WIDE-SECTION PNEUMATIC TIRE

LOW-SECTION PNEUMATIC TIRE

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TRACKED VEHICLES

VARIOUS TYPES OF

TRACTION/TRANSPORT DEVICES

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CHORD CONSTRUCTION IN PNEUMATIC TIRES

TYPES AND SIZES OF PNEUMATIC TIRES

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PNEUMATIC TIRE

TERMINOLOGY

WIDE-SECTION PNEUMATIC TIRE

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LOW-SECTION PNEUMATIC TIRE

TRACKED VEHICLES

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AIR CUSHION FLOATATION SYSTEM

PROPOSED MULTI-LEGGED

WALKING VEHICLE

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UNIVERSAL MOBILE POWER SOURCE FOR

AGRICULTURE.... THE TRACTOR

• TYPES AND SIZES

– 20 to 300+ HP

– 3-point hitch

– PTO

– Remote hydraulics

• PNEUMATIC TIRES

• FLEXIBLE TRACKS

PNEUMATIC TIRE TRACTORS

2-WHEEL DRIVE

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PNEUMATIC TIRE TRACTORS

FRONT-WHEEL ASSIST DRIVE

PNEUMATIC TIRE TRACTORS

4-WHEEL DRIVE

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FLEXIBLE TRACKED TRACTORS

CATERPILLAR CHALLENGER

FLEXIBLE TRACKED TRACTORS

CASE/IH, DEERE, OTHERS

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