Sampling - Field Sampling: Principles and Practices in Environmental Analysis - page 129

FIGURE 5.10 Sampling a field containing a row crop (corn).
the surface. If uniform application has been made, then random sampling is appropriate.
In the case of row crops, however, it is common for some fertilizers and chemicals to
be placed in bands close to or in the row. When sampling this type of field, it is important
to know how the materials were applied so that samples are not taken from areas likely to
have high local concentrations of this material. This is particularly true if the analysis is
for the applied material or one of its components. It is also important because the applied
material may interfere or affect the analysis for other analytes.
A second type of field is one in which the fertilizers and chemicals are only added to
the surface in a uniform manner. This would include both hay fields and grassed areas,
such as golf courses, that are not pastured. A typical hay field is shown in Figure 5.11.
Here random sampling is appropriate.
In the case of fields used for pasture, sampling is a little more complex. Here
completely random sampling is not appropriate. Any place in which