Microbial Succession Law During the Composting Process of Various Livestock and Poultry Manures

The present study was envisaged to investigate the changes in several key indices like temperature, pH and moisture content, and changes in the microbial population size including bacteria, fungi and actinomycetes during the composting process in various livestock and poultry manures. The study was employed with the use of fresh cattle manure, pig manure and chicken manure which were collected from China Shenyang at 2018 year, as raw materials, and 10% cornstalk as a leavening agent to perform a 21-day aerobic composting. Our results indicate: (1) For all three types of manures, the composting processes entered the high-temperature stage (45 degrees C) at the same time (6 days), and the temperature reached to its maxima on the 15th day, with a 6, 6 and 9 days over-55 degrees C period, respectively, which were all above the maturity criteria. (2) For all three types of manures, the pH initially increased and subsequently decreased to a range of 6.9-7.1 at the end of the process, while the moisture content decreased to 34-36%. (3) There was a significant difference in the microbial population of different types of manures. Chicken manure produced the largest number of bacteria (6.72 +/- 1.79 x 10(9) cfu . g(-1) dry weight), while cattle manure produced the least. Moreover, the cattle manure produced the largest number of fungi (8.63 +/- 1.25 x 10(4) cfu . g(-1)dw), while pig manure produced the least. Pig manure produced the largest number of actinomycetes bacteria (9.55 +/- 2.15 x 10(6) cfu . g(-1)dw), while chicken manure produced the least.