ap_01_equipment.qmd

# Equipment

## Profile exposure tools {#sec-digging}

### Hand

Excavation by hand is often the only viable option in New Zealand terrain, which can severely limit vehicle access. A heavy duty steel spade with a wooden handle is the default choice. Other options that might suit particular environments include long-handled fencing spades and narrow trenching shovels. A breaker bar or crowbar may also be needed to loosen the soil before excavating.

Hand augers are common tools for rapid profile extraction, but with the exception of gouge augers for soft muds, the degree to which they disturb the soil profile means that they are better off as an accessory tool. Augering is best confined to well-understood landscapes where quick cores are used to confirm that observations made in nearby pits are representative of the area being sampled. Auger heads useful for soil observations include

-   50 - 100 mm heads for loamy to light clayey soils
-   30 - 50 mm heads for lightly gravelly soils
-   open-ended heads for augering in sands and fine gravels
-   gouge augers for sampling soft muds

Extendable systems are useful for reaching target depths \> 1 m, and systems with shorter rods may offer a better ergonomic experience for shorter workers. Augering safely and efficiently becomes difficult when the handles are above the base of the user's ribcage.

[C1]{.ceg} (@tbl-pr-gear) style tube samplers can be manually inserted with a steel post driver and sampling depths of up to 1 m are usually achievable.

### Mechanical

Mechanical post drivers can be adapted to push [C1]{.ceg} sampling tubes in as deep as 1.5 m, provided the substrate is minimally stony and soil moisture conditions are favourable. Sampling in 30-50 cm sections may be necessary in some cases.

![A researcher using a post driver to extract a [C1]{.ceg} style core in the Ranigitikei River valley.](data/mwlr_postdriver.png){width=70% .lightbox alt="A researcher using a post driver to extract a [C1]{.ceg} style core in the upper Rangitikei River valley."}

Sampling in gravelly, dry-clayey or hard-setting soils may not be feasible without the use of an excavator. Compact models that can be moved on a light trailer are preferred. A narrow bucket gives the operator a choice of pit sizes.

![A pedologist using a small excavator to dig a [P2]{.ceg} style pit in Northland](data/mwlr_excavator.png){width=70% .lightbox alt="A pedologist is seen operating a small mechanical excavator to open up a large sampling pit on an alluvial plain in Northland."}

For deeper sampling, or work in saturated soils, consider the use of vehicle-mounted dual tube sampling systems, where a [C1]{.ceg} core is lined with a removable plastic tube. These are usually pushed into the soil with a hydraulic hammer and the more complex systems can sample to well over 10 m. Another option is vacuum-assisted coring for working below the water table.

Mechanical screw augers are not recommended as they disturb the soil profile too much for a reliable description. Hollow-core screw augers, however, may be able to minimise such disturbance.

## Profile description tools

Essential small tools for a field sampling kit include:

-   Pit tape with large markings, 1-5 m length
-   1-3 m measuring tape
-   Munsell colour book
-   Putty knife or trowel
-   Spray bottle or pressure sprayer
-   Nails, golf tees or small marker flags for noting horizon boundaries
-   Cleaning cloths
-   Notepad/pen, or tablet or field computer
-   Camera or smartphone
-   GPS
-   Clinometer
-   Plastic sample bags
-   Permanent markers
-   Tarpaulin or mat for laying out excavated profiles.

Optional, but useful tools include:

-   Small-diameter 2 mm sieve for removing fine gravel before texturing
-   Gardening clippers for trimming overhanging vegetation around exposures.
-   Medium-bristled brush, for cleaning up exposure faces.

A complete field kit should fit in a medium toolbox or sturdy backpack.

## Field test equipment

A portable field test kit should be contained in a waterproof storage box in case of reagent leaks. Kit contents may include any or all of the following, per @sec-ft:

- Raupach field pH kit (@sec-ft-phf)
- 10% or 1 M HCl (@sec-ft-ca)
- 3-6% H~2~O~2~ (@sec-ft-mn)
- 1M NaF and pre-treated filter paper (@sec-ft-naf)

![Portable field test kit, set up for pH~f~, Naf~f~, Mn~f~ and Ca~f~.](data/mwlr_testkit.png){width=50% .lightbox alt="A photo of an open multi-compartment storage box containing field test kit reagents in small dropper bottles. The box is roughly 20 by 35 cm."}

Portable field pH/EC meters should travel in their own containers along with calibration and cleaning equipment, as well as sample containers and a rack to hold them (@sec-ft-phfw, @sec-ft-phfox, and @sec-ft-ec) . A small toolbox will usually suffice.