Sample Square (IMAGE) American Society of Agronomy Caption Soil samples are collected in a 30 x 30 cm frame, separated into horizons and placed in brown paper bags for transport to the soil analysis lab. Credit Jennifer Knoepp Usage Restrictions For use with story only. License Licensed content 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.