# Mechanical Land Treatments – FFA Land CDE

By Donald G. McGahan, Ph.D.
Revised: April 9, 2017

In contests, officials marks control brush and trees on land classes 5-7 on any size brush. In the Oklahoma manual, it only mentions 1-4. Do you control brush and trees for non-cultivated soil?

I assuming you meant non-cultivated to be non-arable. Where arable is Class I to IV (1 to 4) lands. Specifically, I interpret the question to be asking for the possible Classes of Lands that Number 14 “Control Brush or Trees” under “Mechanical Land Treatment” on the judging card is a possible choice.

See the Land Judging Manual Oklahoma. Quickly scan the Tables (for instance Table 1 on page 9) and identify that rows on the table that have Capability Class VI (6) have number 14 as a “possible mechanical treatment.”

While Class I through IV (4) are considered arable land, non-arable land may benefit from removal of woody vegetation to increase grass growth for livestock, and to decrease woody shrubs from competing for water and nutrients in Timber production or post lots.

Your question did not specifically address a nuance in the paragraph on page 7 of the Land Judging Manual in Oklahoma. “The purpose is to improve the desirable negative cover by removing or killing undesirable brush and trees (Class I to IV).” That passage curiously makes no mention of how one is to determine the size, but the following passage does. “… should not be used when bushy plants and trees are less than two inches (2”) in diameter at 5 feet above ground (Class I to VI).” Note the second passage includes up to Class VI (6) land.

It is an admittedly confusing paragraph.

For simplicity sake if woody (brushy plants and trees is the terminology used in the guide here) is present, is equal to or greater than 2 inches in diameter at five feet above the ground, and the factors Desires Post or Wood Lot or Timber production are not on the condition sheet for that field, number 14 under mechanical land treatments must be considered up to Class VI (6).

This contest does not have guidance for Class VIII land and you can expect to not see it at an FFA Land CDE event. Note also that there is no guidance to use number 14 on Class VII land.

A question arose on class 5 land -or- higher, do you control dewberry (or ANY other brush for that matter) when it is so small that you cannot even see it (smaller than the surrounding grass, clover and vetch)?

The argument presented by the coaches to the steward was that since the field is non-arable, that ANY woody (including woody vines) should then receive brush control.

“Control Brush or Trees” under “Mechanical Land Treatment”

Presumably this would be by both mechanical and chemical means of control at the non-arable sites (Class V and VI).

Since the dewberry was smaller than the surrounding clover, vetch, ryegrass, and rescue grass (and did not have any blooms), the steward did not see it during the set-up of the contest.

The stewards argument was that if the dewberry was taller and plainly visible, then you would consider control. Many stewards have heard the teacher’s argument before on Class V or higher.

Typically, stewards try to include some trees or other brush in the field to make it plainly clear.

The way the Land Judging in Oklahoma manual is structured it leaves ambiguity on page 7:

The purpose is to improve the desirable negative cover by removing or killing undesirable brush and trees (Class I to IV).”

That passage curiously makes no mention of how one is to determine the size, but the following passage does.

 “…should not be used when bushy plants and trees are less than two inches (2”) in diameter at 5 feet above ground (Class I to VI).”

Note the second passage includes up to Class VI (6) land.

For consistency sake using the latter passage for Land and Classes I to VI (1 to 6) and not using it for less than 2 inch woody species is desirable.

For terrace and farming on a contour, you mark when slopes are greater than 1% except when course textured soil is present. Is this if the top soil or subsoil is coarse?

It is the surface soil texture that is used.