If soil samples are collected in a glass jar, what is true?

Placing soil samples in a glass jar with minimal headspace is important for several reasons. First, limiting the headspace reduces the amount of air in the jar, which can help to prevent contamination from atmospheric moisture and gases that may alter the composition of the sample. This is crucial because soil can be sensitive to environmental changes and exposure to air can lead to the loss of volatile components or changes in microbial activity that may skew test results.

Additionally, minimizing headspace helps to preserve the soil’s natural moisture content and prevents drying out, which is particularly important if the samples are to be analyzed for factors such as organic content or microbiological activity. Proper containment of the sample ensures the integrity of the analysis and contributes to obtaining reliable results in any subsequent testing and evaluation.

The other choices suggest practices that could compromise the validity of the samples. Leaving samples exposed to air could lead to significant contamination or degradation of the sample. Using multiple samples in one jar can create variability and complicate the interpretation of results. Maintaining headspace as a non-factor disregards the importance of proper sample preservation. Therefore, ensuring minimal headspace in the glass jar is critical for accurate soil sample analysis.