Grazed Pasture Soil Temporal Variability.

Temporal variability in soil test results may influence when producers can accurately sample their fields to guide fertilization or for regulatory compliance. The objective of this study was to determine the effect of temporal variability on soil tests in a pasture system. Soil samples were collected from two sites; a 6 ha pasture without manure and a 4 ha pasture that received manure. Samples were analyzed for soil pH, inorganic N, and Mehlich 3 phosphorus and potassium. Time of sampling had the strongest influence on nitrogen, while all other soil properties measured were found to remain relatively constant throughout the year. Therefore, not only method of sampling, but also sampling time should be considered relative to sampling objectives.