Effect of Microbial Inoculation and Mineral Amendments on Improving Compost Quality

Abstract

The present work aimed at studying the use of some bioaccelerator, namely Trichoderma viride, T. harzianum, Serratia marcescens, Pseudomonas fluorescence and Bacillus polymyxa, together with mineral materials, that is dolomite, feldspar, rock phosphate, bentonite and elemental sulfur, for production of a reduced time of processing with a high-quality compost. Plant residues composting 40% rice straw + 40%maize stalks + 15% fruit residues + 5% medicinal plant residues were subjected to the composting process. Four compost piles were arranged as follows Pile1: plant residues + 10% FYM; Pile2: plant residues + %5 FYM + mineral additions; Pile3: plant residues + %5 FYM + microbial activators and Pile 4: plant residues + %5 FYM + microbial activators + mineral additions.. The experiment continued under aerobic conditions up to 90 days. The piles temperature reached maximum after 15 days, and then dropped gradually to resemble the ambient one at maturity. Microbial inoculants accelerated the composting process and raised the pile temperature within three days, as compared with the other treatments. Also, the highest temperature degree, i.e. 63Cᵒ was recorded for pile 3. Furthermore, bulk density, contents of total macro and micronutrients, and humification process were increased with progressing of the composting process. While, contents of organic matter, organic carbon and C/N ratio were decreased. Pile 4 achieved higher bulk density values and lowest contents of organic carbon, organic matter and C/N ratio. Incorporation of mineral materials increased the contents of total phosphate, potassium and trace elements, especially in piles 2and 4.