Refinement of loss-on-ignition method for organic matter content in highly amended soils

The purpose of this study was to refine the loss-on-ignition method of organic matter determination based on the previous findings of David Cochran (1980). An additional objective was to develop a pretreatment of organic matter for the reduction or prevention of error due to sample loss from violent eruption caused by rapid exposure to high ignition temperatures.

Pretreatment tests indicated that precharring samples at a temperature of 300° C for 10 minutes prevented loss of samples due to violent eruption at high ignition temperatures. The three sands and eight organic materials were then heated at different temperatures for different time periods. Two of the sands were washed river sands and the third was a mined silica sand. The eight organic materials used were corn stalk chop, cotton stalk chop, Michigan peat, oak sawdust, pine bark, sewage sludge, soybean stalk chop, and sphagnum peat. Temperatures used ranged from 350° to 450° C and time periods ranged from 2 to 8 hours. In all cases the best temperature and time combination was 400° C for 4 hours.