Error Estimates for Nematode Soil Samples Composed of Cores of Unequal Sizes


  • R. McSorley
  • J. L. Parrado


Simulation, Sampling Precision, Nematological Techniques, Meloidogyne incognita


Soil samples for nematode analysis are usually composed of a number of cores collected from random field locations. When collected with a soil sampling tube, they will be of nearly equal size, but if collected with a hand trowel, the size of each individual portion (also referred to as a "core" here) comprising the composite sample will vary. With certain soil types, however, a soil sampling tube cannot be used, and a hand trowel may be the only alternative. Distribution of core sizes collected with a trowel was found to be normal in three fields in south Florida having Rockdale fine sandy loam soil. Simulation was used to compare indices of precision obtained from samples composed of cores of unequal size with those obtained from samples composed of equal core sizes. Nematode density in the composite soil sample was the quantity evaluated, and the index of precision used was the standard error to mean ratio. For samples composed of 20 cores, differences in error estimates were small