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Tillage
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What is Tillage?
the practice of keeping the soil mellow
(soft) and free from weeds mechanically
(physically)
 can be seedbed preparation or
postemergence cultivation

What are the purposes of tillage?
1) develop soil tilth (physical condition of
the soil)
 2) kill weeds
 3) manage crop residue

What is a seedbed?
place where seeds germinate & nourish
young plants
 must be firm to allow seed to come in
contact with soil particles to absorb
moisture
 must be pourous to allow air to move, root
development, water movement
 water will not easily penetrate hard soil to
get to roots

Seedbed Characteristics
if soil is too loose, rain will wash away
young plants
 some soils have excess water
 oxygen is needed by roots
 air and water conduct heat more rapidly
than soil, looser soils warm up sooner
 plant residue on surface insulates, warms up
slower, also provides buffer against wind

What is Soil Tilth?
The physical condition of the soil
 fitness for cultivation

How is good soil tilth developed?
till at proper time to maintain proper
aggregation
 too wet during tillage makes soil lumpy, too
dry during tillage makes soil too fine and
likely to blow
 over tillage will destroy soil structure and
lead to soil compaction

What is the definition of a weed?
a plant that grows out of place
 -tillage can cut roots or bury weeds

Is crop residue a benefit or
detriment?
definitely a benefit
 helps control erosion, retain water, improve
tilth

What is primary tillage?
the first tillage operation of a season
 loosen soil to permit air and water to
penetrate
 dark soils absorb light, warm up quicker
 residue insulates, warms slower
 in wet areas soil is plowed
 in dry areas leave residue

What are the types of tillage
equipment?
• Moldboard Plow: inverts soil, turns residue
under soil surface
Disk Plow

rolling disks, similar to moldboard plow,
better in sticky soils
One-Way Disk Plow

for dry soils, leaves more residue on soil
surface than moldboard and disk plow
What is summerfallow?
tilling uncropped land in summer
 primary tillage is deepest, rest shallower
 leave residue

Chisel Plow
does not invert soil, uses chisels or sweeps
that shatter the soil
 leaves residue on surface

What is Hardpan?
compacted soil layer below the soil surface
 created by continuous tillage at the same
depth

How can hardpan be corrected?

use a subsoiler
Disk Harrow

similar to disk plow except smaller discs,
tandem. cuts residue, but leaves on surface
What is secondary tillage?
all tillage operations after primary
 till at shallower depth

Spike-Tooth Harrow

steel spikes that break soil crust, uproot
small weeds
Rod Weeder
rod turns as it is pulled beneath the soil
 rod turns opposite direction as wheels, lifts
weeds and coarse material to surface
 packs seedbed

Rotary Hoe
hoe wheels on long shaft dig into soil
(shallow)
 usually mounted on tractor for row crops

What is minimum tillage?

delay primary tillage until seeding
What are the benefits of
minimum tillage?
1) soil surface is left covered residue
(conserve moisture)
2) redidue protects soil from erosion
3) reduced costs (fewer operations)
4) soil tilth improved (less compaction)
 -Weeds are controlled with chemicals
What is stripcropping?

alternating summerfallow and cropped
fields
What is contour tillage?
strip cropping so that fields are all at the
same elevation (along hills)
 slows water runoff

What is Terracing?

earth structure built across the slope to hold
water