ANALYSIS OF SOIL PARTICLE SIZE BASED ON THE LASER METHOD

Based on particle size analysis data in Hetao Irrigation District using laser particle size analyzer,selected 12 samples of every soil texture randomly from these samples which the soil texture had been determined,72 samples totally.Tested the selected samples by using hydrometer method.Compared the results tested by the two methods and found the differences and conversion relationships between the two results.Verified the established conversion models and determined the consistency of the soil texture.The results showed that the clay contents tested by the laser method were lower than those tested by the hydrometer method,while the sand content determined by the former were higher than those by the later.The silt contents varied with no consistent difference.The mean square error of the forecast data of clay,silt and sand contents were 2.48,6.13 and 5.19.The concordance on the soil texture determined increased from 38% to 67%,while the consistency on the soil category increased from 54% to 91%.The transforming relationships could effectively improve the consistency of the two methods.The study result provided a reference for converting the particle size measured by the laser method and determining soil texture.It will promote the popularization and application of laser particle size analyzer in the discipline of agricultural soils in Hetao irrigation District.