Is it O.K. to use raw sawdust or raw ground bark as a soil amendment?
The soil microorganisms responsible for converting organic material into plant nutrients consume nitrogen as they go about their work. Most plant materials contain enough nitrogen to meet this need. Raw sawdust and raw ground bark, however, contain very little nitrogen forcing the microorganisms to take nitrogen from the soil to meet their nutritional needs. Eventually the nitrogen is returned back to the soil but the overall effect is that the use of raw sawdust or raw ground bark causes a temporary drop in the available soil nitrogen. If raw sawdust or raw ground bark is to be used as a soil amendment, it should be supplemented with a nitrogen rich fertilizer such as fish meal or blood meal.
