Get the most from your Johnson Bucket Auger.

Certain requirements need to be observed for the efficient use of this handy tool.

In the first place, large numbers of boulders and stones (larger than 25 to 30mm in diameter for example) will preclude the use of an auger and it has to be accepted that the pick and shovel will have to come out! Secondly a disciplined and methodical procedure as outlined below will make it possible to describe practically all important pedological characteristics of the soil profile. Some agronomic information, notably root development and distribution, cannot be observed easily and profile pits are more satisfactory.

The Auger

The 100mm bucket auger has been found to be the most effective, it penetrates all soil types easier than the 75mm and produces larger clods to examine, for example to assess permeability and structure. The shaft should be marked off in convenient depths (commonly 30 - 60 - 90 mm from the bottom of the bottom of the auger bit). Finally, the 70cm handle has obvious advantages in leverage when conditions are difficult.

(Shaft lengths are available for drilling 120cm or 150cm+ deep holes)

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The Procedure

Start off by cleaning a strip (remove loose stones and vegetation) about 2m long, a short distance upwind of the auger site, using a small trenching tool or spade.

 

A small hole is then dug, about 10cm deep, to ease the initial penetration of the auger. The soil from this hole forms the first pile in the strip, preferably at the point furthest from the auger hole.

 

The auger is removed from the hole as soon as it is full (after two or four full turns) and it is important to partially invert the auger, well away from the sample stripes, and discard the first third of the contents of the bucket as this often becomes contaminated by spoil from above, particularly while the auger is removed from the hole.

 

The remaining soil is then emptied from the auger barrel, taking care not to destroy the all important clods. A sharp bang on the ground, handle first, with the auger vertical, helps to clear the auger.

 

The samples are placed in a straight line in consecutive piles with small gaps marked where the augered depth matches the marks on the auger shaft.

 

The strips of samples then provide a realistic representation of the vertical soil profile down to the depth of any limiting horizon or the depth augered.

 

 

Examination

With the various horizons clearly visible, it is possible to take samples, determine texture, (clay percentage), permeability, structure, root frequency, degree of mottling, colour, the nature of the limiting horizon and any other important characteristics.

 

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