Variation in the soil from place to place is a fact of nature and is substantial. It is a major source of uncertainty in soil survey and causes many of the difficulties of applying mathematics to the study of soil. Soil variability within small areas can be studied by using a straight line (transect) laid over a tract of known distance and can be sampled and observed equidistantly.
Line transects give an indication of both the local and the general variation. The technique, however, may depend strongly on direction of the transect. Soil along the LTER I Control transect was sampled at 30 meter intervals from station C01 through C89. Soil characteristics were measured at 4 depths (30, 60, 90, and 120 cm) for the percent composition of clay, silt, sand, very coarse sand, coarse sand, medium sand, fine sand, very fine sand, calcium carbonate, organic carbon and coarse fragments greater than 2mm.
Data file information for the following Jornada data set: Transect Particle Size Analysis