Soil heterogeneity and soil testing.

  • T.J. Ferrari
  • F.H.B. Vermeulen


The error of analysis is generally small. The standard deviation influenced by analysis and sampling averages 10% in P, K and Mg determinations. The error in pH value is approximately 0.1 per unit. There is little difference between grassland and arable land or between various types of soil in this respect; the size of the field has, on the average, no effect on the magnitude of sampling error. If it is desired to compare results of samplings of the same field taken in certain intervals, changes due to climate, farming operations, etc. have to be taken into consideration. The longer a field is under observation, the greater will be the significance and value of soil testing.- From authors' summary. (Abstract retrieved from CAB Abstracts by CABI’s permission)