What is the most common source of error in soil test results?

Improper sampling is recognized as the most common source of error in soil test results because the way samples are collected significantly influences the accuracy and reliability of the test outcomes. If soil samples are not taken correctly—from the wrong depth, inconsistent areas of the field, or mixed with unrepresentative soil types—the results may not reflect the true nutrient status of the soil. This can lead to incorrect fertilization recommendations and ultimately affect crop health and yield.

In contrast, while inaccurate measurement, contamination, and inadequate analysis can contribute to discrepancies in test results, they are generally less common compared to the potential pitfalls associated with improper sampling techniques. Proper sampling protocols are essential for achieving reliable results that can guide effective nutrient management decisions.