A sample can consist of one, two, three or four pairs of PRS® probes:
Recommended number of PRS® probes per sample:
Sampling unit | PRS® Probes per sample* |
---|---|
Well-mixed soils (lab, greenhouse) | One or two pairs |
Small plots (1 to 10 m2), uniform soil and vegetation (e.g., tilled annual cropland, grass on uniform soil type) | Two or three pairs |
Small plots (1 to 10 m2) with heterogeneous soil, fertility amendment or vegetation | Three or four pairs |
Large plots (>10 m2) with heterogeneous soil and vegetation | Three or four pairs, one or more samples per sampling unit |
*Number of probes per sample and samples per sampling unit depends on objectives, experimental design and measurement variation. When possible, evaluate statistical power of proposed experiment based on preliminary evaluation of treatment differences and measurement variability. |