Zone sampling tends to group samples based on what characteristics?

• A. Zone sampling groups samples by areas with similar characteristics or management.
• B. Zone sampling uses a fixed grid with uniform spacing.
• C. Zone sampling requires only one sample per field.
• D. Zone sampling is identical to random sampling.

Answer: (A)

Zone sampling targets field variability by dividing a field into zones that share similar characteristics or management needs. By sampling within each zone, you get a more accurate picture of fertility across the field and can tailor fertilizer applications to the conditions in each part, rather than treating the whole field the same. This approach relies on recognizing differences in soil properties, moisture, crop history, and other factors that affect nutrient availability. It differs from a fixed grid, which uses uniform spacing regardless of how conditions vary across the field. It isn’t limited to one sample per field, since multiple samples across distinct zones are needed to characterize each area. And it’s not the same as random sampling, which ignores spatial patterns and management zones.