Nuts and Bolts of Imprinting

How the Imprinting Machine Works During the past two decades, the

general specifications for land

imprinters were derived from the

principles of soil mechanics and the

hydro-biotic function of soil imprints.

Mechanically, imprints are formed

through downward acting forces applied

to angular steel teeth. Troughs or

indentations are formed through soil

compression and shearing, whereas

adjacent crests or ridges are formed by

an embossing (lifting) process. Thus,

the original soil surface lies in a plane

about midway between the imprint

trough and crest. A 5-cm (two inch) gap

around each tooth facilitates these two

interacting processes with minimal soil

disturbance and compaction. Imprints are 25-cm (10 inches) long, V-

shaped troughs or micro-watersheds

which funnel resources to the bottom of

the vee where they can work in concert

to germinate seeds and establish

seedlings. Each micro-watershed is

about 30-cm (one-foot) square in

surface area and can hold several liters

of rainwater on level ground. This is

enough water to germinate and

establish one or more seeds or

seedlings. Imprints are staggered and

separated by 5-cm (two inch) wide dikes

at the soil surface for safe storage of

rainwater until it infiltrates. The

staggering also gives plants more room

to develop and better exposure to vital

resources including water and light.

Imprints that satisfy the general

specifications are pictured in figure 1.

Such imprints will almost always lead to

successful if the seed mix is adequate.

Such imprints are stable enough to wait

several years for adequate rain to occur

in the desert.

The Roller Blades Roller Categories

To assist readers who wish to make

their own imprinters, specifications are given in U.S. Customary (English)

units. The structural steel used to

fabricate imprinters is available in

these units. Conversion factors are

given for the convenience of those

working in countries where steel has

metric dimensions. Six categories of imprinting rollers

result from various combinations of 2

angle sizes (6"x 6" & 8" x 8"), 2 angle

shapes (straight and bowlegged) and

two cylindrical core diameters (20" &

24"). Category specifications are

given in the table below. Angular teeth

are welded radially around the core to

form 6 or 8 pointed star rings. Tooth

length is 10 inches and the spacing

between rings is about 2 inches. Thus, there is one star ring for each 12

inches of imprinting roller length.

Points on adjacent star rings are

staggered to suppress gully formation. The radial basal spacing of imprinting

teeth is also about 2 inches. This 2-

inch gap around the base of each

tooth improves penetration into the

soil while providing a dam between

adjacent imprints for safe storage of

collected rain or irrigation water until it

infiltrates. All six categories of

imprinting rollers make imprints or

micro-watersheds about 12 inches

square in size and shape. These small isolated watersheds provide excellent

control of infiltration and the micro-

climate, thereby greatly accelerating

re-vegetation processes. The Tow Frame The front and rear of the tow frame are

square tool bars which permit the use of

commercial tool clamps for easy attachment

of hitches and accessories (Figures 1 & 2).

Typically the draw bar tongue is removed for

trailer hauling to reduce the width of the

load. Since the front and rear of the tow

frame are identical, hitches can be attached

to either side to reverse the direction of

roller rotation. This feature nearly doubles

the life of imprinting teeth, the tips of which

concave sharpen on their leading edges

Web Design by Thumbs Up Production

Click on pictures to enlarge/read -- double click to reduce Figure 2 Tow frame and imprint rollers with

loading/unloading wheels attached.

• Frame Shape and Size: Rectangular to fit

rollers 3,4,5,6,7,8,9 & 10 feet in length • Rear tool bar: (2 ¼-inch side) • Frame Ends: Clamped to tool bars with

center bearing bracket • Roller Axle:Full-length, cold-rolled steel, 2 ½-inch diameter • Axle Bearings: Pillow block type with cast

steel housing and double tapered roller

bearings • for 2 ½-inch axle • Tool Attachments: • (1) Draw bar tongue for field operation • (2) Trailer loading and unloading wheels • (3) Three-point hitch (optional) • (4) Ripping Arms (optional) Figure 1: Imprinter tow frame attached to a

dozer blade to form a steep-slope imprinter.

Tractor hydraulics force imprinting teeth into

the ground. Category II, 7-foot imprinting rollers designed for re-vegetating steep slopes. Well-formed imprints efficiently establish

vegetation on severely degraded land.

Ripping shanks at the rear of the tractor

loosen hard soil spots enough to imprint.