Tillage glossary A Presentation By Mr Allah Dad Khan Agriculture Expert KPK Pakistan

3.  The mass of dry soil divided by the bulk volume. Bulk
density is not an absolute indicator of compaction
because root limiting density varies with texture. Root
extension is generally limited by bulk densities >1. 6
g/cm3 in silt loam soils; 1.6 g/cm3 is unlikely to be
limiting in sandy soils and is severely limiting in clayey
soils

4.  Any tillage system that maintains 30 percent or more
of the soil surface covered with plant residues after
planting. Where soil erosion by wind is the primary
concern, any system that maintains at least 1,000
pounds per acre of flat, small grain residue equivalent
on the surface throughout the critical wind erosion
period.

5.  (intensive tillage)—full width tillage that disturbs all
of the soil surface and is performed prior to and/or
during planting. Less than 15 percent of the soil is
covered with residue after planting, or less than 500
pounds per acre of small grain residue equivalent
throughout the critical wind erosion period. Generally
involves inversion of a plow layer or multiple field
operations with non-inversion tools. Weed control is
accomplished with crop protection products and/or
cultivation.

6.  —surface compaction resulting from raindrop impact,
particle detachment, and size-sorting, leaving the
finest soil particles concentrated at the surface.
Impedes infiltration, gas exchange, and seedling
emergence.

7.  —rolling circular blades that have straight or fluted edges
and are intended to cut residues, pulverize soil structure,
and/or level the soil surface. Disks are often mounted in
groups (gangs) of parallel blades. In a tandem disk harrow,
leading and following disk gangs are mounted with
opposite angles such that soil is first moved out and then
back in. The amount of soil movement caused by disks is
related to the angle of the disks, the down pressure on the
disks, the design of the blade (straight or fluted), and the
speed at which the disks are pulled. Single disks (coulters)
designed to cut residues often precede other ground
engaging tools in equipment designed for high residue
conditions. Disks are often arranged and used to shape
beds.

8.  In contrast with no inversion tillage, inversion tillage
flips over a layer (often 6–12”) of soil, burying surface
residues (and associated weed seeds, spores, and
insect larva and eggs) in the process. The result is a
surface with minimal residues that can be easily
managed using traditional secondary tillage
equipment, but is susceptible to erosion. The
moldboard plow is the standard inversion tillage
implement. Disk plows also perform inversion tillage.

9.  (reduced till)—tillage system that does not involve
soil inversion and maintains a high level of surface
residue.

10.  Moldboard plow—traditional primary tillage tool
consisting of the following key ground engaging parts:
the plow share (slices the soil horizontally), the
moldboard (lifts and rolls the soil, bringing about
inversion), the landside (transfers the sideways
thrust), and the coulter (slices the soil vertically). The
coulter is essential if plowing sod or soil with
significant residues. The moldboard plow is often the
best tool for breaking sod.

11.  —full-width tillage involving one or more tillage trips
that disturbs all of the soil surface, and is done prior to
and/or during planting, but leaves residues
concentrated at the soil surface. Tillage tools such as
chisels, field cultivators, disks, sweeps, or blades are
used. Weed control is accomplished with crop
protection products and/or cultivation.

12.  No till (zero tillage, direct drilling, or transplanting)—
tillage system that maintains residues (even in row)
and plants through these residues using specially
designed equipment.

13.  layer immediately below the depth of regular tillage.
Moldboard plows, disks, and rotary tillers are
notorious for creating plow pans.

14.  —tillage used to break or fracture soil for a depth of six
or more inches. Primary tillage implements vary in
their ability to penetrate high-strength soils and cut
through plant residues. Examples include moldboard
plows, heavy disks, spading machines, heavy rotary
tillers, chisel plows, and subsoilers.

15.  —tillage designed to disrupt aggregates and disperse
clay, creating an impermeable layer that will perch
water. Puddling is a tillage objective in flooded rice
systems, but is undesirable in other production
systems.

16.  Tillage system that uses cultivation to build or rebuild
ridges during the early part of the growing season, and
then plants the next crop on ridges that have had the
top sliced off during the planting process.

17.  Tillage used (generally following primary tillage) to
pulverize, level, and/or condition soil less than six
inches deep to prepare or “fit” a seed bed.

18.  —acts a lot like a chisel plow but allows shanks to
spring back when sufficient resistance is met (such as
when striking a rock).

19.  —a holistic term referring to favorable soil physical
properties for agriculture. Soils with "good tilth" are
friable, can be tilled with less draft, and allow tillage
objectives to be easily achieved. Similar terms include
describing the soil as “mellow”, having good
“condition”, or “works like a garden”.

20.  —straight or curved, stiff or flexible, and varying with
respect to angle of soil contact, tines modify soil
structure by a range of processes, including, cutting,
lifting, and vibration, that transfer draft energy to the
soil through the tine. Stiff tines are often referred to as
shanks. Tines generally do not create significant down
pressure and thus do not compact the soil below the
depth of tillage. Flexible tines vibrate as they are
pulled through soil and this vibration contributes to
the shattering of soil structure.

21.  —deep tillage designed to create vertical zones of
fractured soil (generally in row) that promote more
extensive rooting.