Comparison between aerobic and anaerobic co-composting of agricultural residues

Fertile soil is the most important resource for food production. The agricultural area in Egypt is limited to 6 million faddans. This limited area has derived many farmers to use several types of chemical fertilizers, to enhance the fertility of the land and hence the productivity. Excessive application of chemical fertilizer lead to the build up of these residuals because they are superfluous. This will cause waste of money and also soil pollution. Ultimately, this would adversely affect the ecological system in the soil and surrounding environment, especially water bodies. Composting of organic solid wastes will address some of the problems of solid waste disposal and gives a beneficial product which may replace the expensive chemical fertilizers. Other organic compostable solid wastes could be utilized to produce this compost. Agricultural residues are cheap raw materials for such compost and are available in vast quantities as well. This compost can be used as a soil conditioner to improve soil characteristics and its productivity. Crop residues mixed with manure, may be co-composted to give a soil conditioner. Agricultural residues, about 106 million tons/year, may produce about 55 million tons/year of compost. Three co-composting were carried out at the experimental station of the Faculty of Agriculture in Abis. Two aerobic co-composting of winter and summer crop residues and one anaerobic co-composting inter rop esidue were produced. The development of the co-composting processes controlled by the temperature, moisture content, and chemical composition was studied. The aerobic co-composting of winter crop residues was found to be the best experiment as it complied with the standards of the Ministry of Agriculture Decree No. 100/1967. This co-compost is expected to be free from pathogenic microorganisms as the dominant temperature was almost about 50 degrees C from the 42nd day till the 101st day of the experiment.