Soil Sample Preparation (image) American Society of Agronomy Share Print E-Mail Caption Preparation of soil sample for visible near-infrared spectroscopy measurement. An air-dried and 2-mm sieved soil sample is poured into a rotating sample cup with transparent quartz window. Credit Maria Knadel Usage Restrictions Please use with story only Share Print E-Mail Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.