CROP PRODUCTION
Unit 7: Tillage & Seeding

Tillage & Seeding (149)
 Tillage – manual or mechanical soil stirring
actions
 Tillage Systems – type and sequence of
tillage operations used for proper
establishment and growth of crops

Goals & Purposes (149)
 Seedbed Preparation – provide optimum
environment for seed germination and
subsequent growth
– Temperature
– Moisture
– Aeration
– Seed-to-soil contact
 Incorporating and mixing – crop residues, lime,
fertilizers, and/or pesticides
 Weed control
 Conservation of soil & water – prevent erosion
conserve precipitation, and improve infiltration

Tillage Vocabulary (150)
 Primary Tillage – inverts or shatters soil 6-14
inches deep; leaves the soil rough
– Loosen and aerate surface layer
– Incorporate fertilizer
– Cover plant residue
 Secondary Tillage – follow primary tillage; depth
is 2-6 inches deep
– Prepare final seed bed
– Level and firm soil
– Pulverizing soil for seed-to-soil
contact
– Control weeds

Tillage Vocabulary (150)
Tillage Implements – vary widely
among engineers,
agronomists, manufacturers,
and producers
Compaction – soil has few or no
pore spaces, creating a poor
environment for plant roots;
measured with a penetrometer
(on right)

Primary Tillage
Implements
 V-ripper
 disk plow
 disk ripper
 sweep plow
 lister/bedder
 moldboard plow
 powered rotary tiller
 chisel plow—combo

Secondary Tillage
Implements
 disk harrow
 roller packer
 field cultivator
 spring- spike- &
tine-tooth harrows
 seed bed finisher
 row-crop cultivator

Tillage Systems (156)
– Conventional tillage: normal primary
and secondary operations – varies
from region to region
– Clean tillage: leave little or no residue
on soil surface
– Mulch tillage: leave residue to reduce
soil/water loss
– Conservation tillage: leave >30%
residue cover on soil surface
– Minimum tillage: systems that employ
the least amount of tillage required

Tillage Systems (Con’t) (156)
– Reduced tillage: utilize fewer or less
energy intensive operations
– Full-width tillage: tillage of entire field
surface
– Strip tillage: tillage of strips, leaving
undisturbed strips
– No-till: seed planted directly into
previously undisturbed soil
– Ridge tillage: ridges/furrows
established & maintained throughout
the year

Tillage Methods (156)
 Clean, full-width tillage systems
– Conventional tillage
– Plow and combined secondary tillage
– Plow and strip-till planting
– Plow, listing, and planting
– Other clean, full width tillage systems

Tillage Methods (159)
 Conservation tillage systems
– Full width conservation tillage
• Chisel plow systems
• Disk (and/or field cultivating) and plant
• Sweep tillage
– Strip till conservation tillage
• Lister-planting
• Strip rotary tillage
• Till-plant
– No till

Tillage Operations for Special
Situations (164)
 Sub-soiling: used to break up
impervious layers which limit
root growth and nutrient and
water holding capacities of the
soil
– Depths greater than 13-14 inches
 Extremely deep primary tillage:
as deep as four feet; turn up soil
that has been buried

Tillage for Weed Control (165)
 Tillage before planting – as
weeds germinate and begin
growth
 Tillage after planting and
before crop emergence is
completed – both weed
control and breaking soil
crusts
 Cultivation after crop
emergence – most
economical and surest
method for weed control

General Considerations (166)
 Agronomic aspects in adopting tillage systems:
– Soil and climatic factors – more crop residues = lower soil
temps and higher OM levels
– Seed and fertilizer placement – heavy residues interfere with
seed placement, covering seed with soil and seed-to-soil
contact; fertilizer may be highly unavailable
– Pest control – reduced tillage systems allow weeds seeds to
remain near surface
– Soil conservation – erosion directly linked to surface residue
 Economic aspects in adopting tillage systems –
primary consideration is net profit over long period of
time

Objectives of Seeding (169)
 Proper depth placement – large seeds have large
food reserves and longer hypocotyl/mesocotyl; in
some soils, moisture is unavailable at shallow
depths
 Good seed-to-soil contact – proper planting
procedure and equipment; proper tillage; avoid
“crusting”
 Proper rate and distribution – germination and
purity; competitive ability; other environmental
factors: canopy, tillering, competition w/other
species

Objectives of Seeding (172)
 Time of planting – late planting can lead to
lower yield
 Row fertilizer placement – side-band, split
boot, and pop-up

Manual Planting (173)
Problems:
– Uneven depth
– Uneven spacing
– Uneven covering of seed
– Excessive soil compaction

Mechanized Planting (173)
Row-crop planters – drill
patterns, hill-drop pattern,
check row pattern
Grain drills
Broadcast seeders –
disadvantages such as uneven
distribution/spacing, poor soil
contact, requires higher
seeding rates
Specialized planters – potato
planters, vegetable seed
planters, and tobacco planters

 Website resouces:
– http://www.wtamu.edu/%7Ecrobinson/TILLAGE/tillag
e.htm
– http://www.deere.com
– http://www.wil-rich.com/
 Chapter 7
– Review Questions (p. 182-184)
– Thinker