Biological activities during ripening of composts

Three investigations were carried out. The first determined the relationships between dehydrogenase acitivty throughout the course of composting wheat straw and the changes in both organic carbon and total nitrogen. The second investigation tested the validity of the first investigation results. The third dealt with the effect of the degree of ripening of a compost, expressed by age and C/N ratio, on its dehydrogenase activity, and production of CO2. The results revealed continual decreases in the organic carbon, coincident with increases in total N and dehydrogenase activity. Noticeable chemical and biological changes occurred in the first and third month. Levels of dehydrogenase were highest in rice straw and lowest in cotton stalk compost, while the wheat straw compost occupied an intermediate position. Aging of the compost resulted in increases in the dehydrogenase figures and decreases in the amounts of CO2 produced.