Which of the following is NOT a method for sampling soil?

The correct answer is that wooden crates are not a method for sampling soil. Soil sampling typically requires containers that can securely hold soil without contamination or alteration of the sample.

Plastic bags are commonly used for small, individual samples while ensuring that the moisture and composition of the soil are maintained. Glass jars serve a similar purpose, providing a stable environment for soil samples, particularly when chemical analysis is expected, as they are non-reactive and can be sealed tightly. Centrifuge tubes, although less common for bulk soil sampling, can be effective for collecting smaller samples where precise measurements and handling are important.

In contrast, wooden crates may not provide the necessary isolation from external elements or the sealing required to preserve the integrity of the soil sample for analysis. They could also introduce contaminants from the wood itself, making them unsuitable for the specific requirements of soil sampling. This understanding of sampling methods is essential for the accurate assessment of soil for lead and other contaminants in environmental health and safety practices.