Which statement about sampling when multiple soil types are present is correct?

• A. Composite samples should be mixed across the entire area
• B. Samples should be collected only from the top two inches
• C. Foliage should be included in turf soil samples
• D. Composite samples should be assimilated separately for each distinctive soil-type area

Answer: (D)

When multiple soil types are present, you need to respect how soil properties vary across the landscape. The correct approach is to identify each distinctive soil-type area and create a separate composite sample for each one. This way the lab results reflect the unique pH, nutrient holding capacity, and texture of every soil type, allowing targeted recommendations for each zone rather than an averaged result that could mislead management. Mixing subsamples from all areas into a single composite would mask these differences and could lead to over- or under-amending in various spots. Also, sampling only the top two inches misses the root zone where most turf roots extend and where nutrient dynamics differ with depth, and foliage is not part of soil testing. By handling each soil-type area separately, you get accurate, zone-specific guidance for uniform turf performance.