Sand as a soil separate consists of mineral soil particles that are 0.05 mm to 2 mm in diameter. In the database, the estimated sand content of each soil layer is given as a percentage, by weight, of the soil material that is less than 2 mm in diameter. The content of sand, silt, and … Continue reading Download Iowa Soil Sand Content Maps (gSSURGO)
Because laser diffractometry produces much more detailed data than does traditional pipette analysis, and because a much smaller sample is used in the analysis, precision or repeatability of laser-produced PSA data is a concern. The approach presented provides both a simple method for assessing the variation in PSA data sets and establishes a comparable standard for determining when additional measurements are needed to find a more precise result.