Use clean equipment. Collect samples with a stainless steel probe, spade, or shovel. Mix samples in a clean, plastic bucket. If fertilizer or other chemicals have been in the bucket, wash it thoroughly before using it. Sample each unique area separately.
Fields often vary in slope, color, drainage, or texture.
If you have previously divided a field into sections for various crops, submit a sample for each section even if you now plan to grow the same crop across the entire field. Avoid sampling in fertilizer application bands. Such samples can distort evaluations of your field's nutrient-supplying capacity. Sampling patterns for a field with three distinct soil types. Sample to the appropriate depth.