The need for knowledge on broad ranges of SOM content exists for proper application rates of certain residual herbicides, for potential N contributions to crops, and for general knowledge on changes in soil quality due to management practices that either favor soil erosion and accelerated SOM decomposition, or increase cover and crop residues. A quick field method to meet these objectives would be desirable. A method would be based upon the appropriate weighing and prioritizing of all these factors.
Any field method requires basic steps that are easy to follow by operators from a field office.
Thus, some accuracy is normally sacrificed for simplicity and ease of operation. The field method, though, still must distinguish and separate significant differences in SOM as required by its users. Thus, the darker the extract, the higher the SOM content. The method is routinely used in many laboratories, but could be modified for quick SOM assessment in the field. Because of the hazard and disposal problem, this method should be used sparingly.