Microbial consortium culture and vermi-composting technologies for recycling on-farm wastes and food production

Girish Chander,Manoj Kaushal,A V R Kesava Rao,Swati Chaudhury,Ankita Mahapatra,Suhas P Wani,C S Pawar,S Gopalakrishnan

doi:10.1007/s40093-018-0195-9

Abstract

PurposeA study was conducted to characterize the ‘Madhyam culture’ (Excel Crop Care Limited.), an aerobic-composting microbial consortium culture, and understand composting dynamics, product quality and use in crop production vis-à-vis vermi-composting (using earthworms).Methods16S rDNA analysis was used to characterize aerobic-composting culture. Aerobic-composting and vermi-composting technologies were evaluated to decompose sorghum straw and dung biomass (80:20 ratio; primed with 0.5% urea and 4% rock phosphate) to study days to maturity and composting dynamics in terms of changes in temperature and microbial population. Compost quality was tested for macro-, micro-nutrients and C:N ratio, and evaluated for food production in on-farm trials.Results16S rDNA analysis screened sixteen bacterial isolates—eight related to genus Bacillus, three to each Halobacillus and Staphylococcus, one to each Microbacterium and Streptomyces. The population of bacteria was 4.5 cfu ml−1 at 10−7 dilution. Aerobic- and vermi-composts matured in around 50 and 60 days, respectively. Aerobic-composting throughout recorded relatively higher bacterial population, and higher temperatures during the initial phase. Aerobic-compost tested for high nutrient (1.55% N, 0.93% P, 1.00% K) content and stable C:N ratio (10.3) compared to vermi-compost (1.11% N, 0.43% P, 0.96% K and C:N ratio of 11.7). Field evaluation of both composts showed yield benefit and saving of chemical fertilizers up to 25%.ConclusionsAerobic-composting (using microbial consortium culture), like vermi-composting, proved to be an effective technology with advantage of no requirement to maintain ambient living conditions in lean periods as is required for earthworms in vermi-composting, but needs more energy/labor for biomass turnings.

Highlights

Low soil organic carbon (C) levels and macro, micro-nutrient deficiencies due to soil mismanagement and misuse are the major challenges for improving productivity in the semiarid tropics (Chander et al 2015)
The colonies that appeared at the end of incubation were enumerated as colony forming units (CFU) per gram of sample on dry weight basis
A total of 21 bacterial isolates including one actinomycete were isolated from nutrient agar plates and Bennett’s agar plates based on the colony morphology, color and shape

Summary

Introduction

Low soil organic carbon (C) levels and macro-, micro-nutrient deficiencies due to soil mismanagement and misuse are the major challenges for improving productivity in the semiarid tropics (Chander et al 2015). Soil organic C is one of the most important parameters governing soil health through influencing soil chemical, physical and biological properties, and thereby influencing crop yields as well (Wani et al. RP: Asia, International Crops Research Institute for the Semi-Arid Tropics (ICRISAT), Patancheru, Telangana 502324, India. In India, ~ 350 million t organic wastes are generated annually from agricultural sources (Pappu et al 2007), and so recycling C and nutrients contained in such wastes is potential opportunity for soil C-building and cutting costs of chemical fertilizers (Chander et al 2013; Nagavallemma et al 2006)

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Conclusion