Simple, low-cost image analysis of soil pore structure

A low-cost method to obtain and analyse digital images of prepared soil sample faces is described. Soil samples are stabilized and pore space is highlighted using a hard-setting resin. The sample faces are photographed using a 35 mm SLR camera fitted with a macro-lens and digital images of the negatives or slides are transferred on to Kodak Photo-CD. The images are analysed using custom-written software on a standard IBM-compatible PC. Various soil structural characteristics are evaluated that have previously required greater resources for evaluation. The method is illustrated with images of three contrasting soil compaction treatments from a field experiment and the results obtained are examined in relation to gas movement measurements. (C) 1997 Silsoe Research Institute.