When sampling soil, it is usually recommended that one collect a small amount of soil from a number of locations within a field, then mix the soil together in a pail for a good, representative sample. The reasoning behind this approach is that soil nutrient level tends to vary across a field due to the heterogenous nature of soil. This natural variation is further compounded when fertilizer and lime are applied, because of occasional missed streaks or overlaps with normal application equipment and methods. Sampling instructions typically call for collecting 2-5 cores or subsamples per acre within the field.
Questions sometimes arise as to whether one has to collect so many subsamples.
More specifically, what is the minimum number of subsamples needed for a representative sample. The experimental area chosen was approximately one acre in size, was in a long-term tall fescue sod, and had received minimal maintenance over the years. The field was sampled on a 40' x 40' grid with a total of 25 sampling location points. Soil pH data are presented in Figure 1. 5.3 5.2 5.7 5.7 4.9 5.1 5.6 5.5 5.5 5.4 6.0 4.9 5.4 5.3 Figure 1.