Composting of Greenhouse Tomato Plant Residues, Wheat Straw, and Separated Dairy Manure, and the Effect of Free Air Space on the Process

This study investigated the optimum mixture ratio of greenhouse tomato plant residues, wheat straw, and separated dairy manures for composting. Five 127-L laboratory-scale bioreactors were used to investigate the effect of separated dairy manure addition on the composting process of a tomato plant residues-wheat straw mixture. The wastes were mixed at 5 different ratios during the trials and were then placed in the reactor. Whereas the C/N ratios of the material mixtures placed in the reactors were fixed at a level of about 31, the FAS values ranged between 24.56% and 32.64%. Temperature and CO2 measurements were made from the reactors during the trials along with organic matter and moisture content analyses. According to the results, the optimum mixture ratio for composting the experimental materials was found to be 60% tomato waste, 10% wheat straw, and 30% separated manures on a dry basis. The FAS ratio of this mixture was 30.22%.