Future Farmers of America (FFA) Agronomy Career Development Events (CDE) Practice Exam

The best practice for collecting plant samples for nutrient analysis involves digging up the plant along with its root system and placing both the roots and soil in a plastic bag. This is correct because a comprehensive assessment of plant health and nutrient content requires the analysis of both the aerial (leaves and stems) and underground (roots) parts of the plant. Roots play a critical role in nutrient uptake, and including soil provides context for understanding the nutrient availability in the environment.

Additionally, analyzing only the leaves or stems (as suggested in other options) may lead to incomplete or misleading data, as they do not provide a full picture of how nutrients are acquired and utilized by the plant. Sending dry samples directly is not ideal since moisture content can affect nutrient concentration measurements, and conditions during shipping can compromise sample quality. Collecting only parts of the plant disregards the importance of the whole organism's role in nutrient dynamics. Therefore, option B stands out as the most effective and accurate practice for nutrient analysis in agronomy.