Optimization of Fly Ash Incorporation into Cow Dung-Waste Paper Mixtures for Enhanced Vermidegradation and Nutrient Release

Abstract

This study was conducted to establish an appropriate mixture ratio of fly ash (F) to optimized cow dung-waste paper mixtures (CP) to develop a high-quality vermicompost using earthworms (). Fly ash was mixed with cow dung-waste paper mixtures at ratios of (F:CP) 1:1, 1:2, 1:3, 2:1, and 3:1 or CP alone and composted for 14 wk. Olsen P, inorganic N (NO, NO, and NH), C:N ratio, ash content, microbial biomass C, and humification parameters were measured together with scanning electron micrograph images to determine compost maturity. Based on C:N ratio, the extent of vermidegradation of the waste mixtures followed the decreasing order (F:CP) of 1:3 > 1:2 > 1:1 > CP alone > 2:1 > 3:1. Similarly, Olsen P was significantly higher ( < 0.05) where earthworms were added. The mean percentage increase in extractable P was in the order CP alone > 1:2 > 1:3 > 1:1 > 2:1 > 3:1, with earthworm addition almost doubling P release across the 1:1, 1:2, and CP alone treatments. Fly ash incorporation enhanced conversion of organic N to the plant-available inorganic forms, with the 1:3 treatment resulting in the highest conversion. Scanning electron micrograph images confirmed the extent of vermidegradation reflected by the various humification parameters determined. Fly ash incorporation at the 1:2 ratio proved to be the most appropriate because it allows processing of more fly ash while giving a vermicompost with desirable maturity and nutritional properties.

Vermicomposting manure-paper mixture with igneous rock phosphate enhances biodegradation, phosphorus bioavailability and reduces heavy metal concentrations

“…(2010) . Prior to enrichment with rock phosphate, the mixtures were moistened to a moisture content of 60% ± 10, and pre-composted for 1 week to eliminate volatile toxic gases, which are harmful to earthworms ( Mupambwa and Mnkeni, 2015 ). The treatments in this study consisted of different levels of P enrichment applied as igneous rock phosphate i.e.…”

“…The chloroform fumigation–extraction procedure was used for determination of microbial biomass C in compost samples based on the methods of Vance et al. (1987) and as outlined in detail by Mupambwa and Mnkeni (2015) .…”

“…Incorporating waste paper into cow dung has been suggested as one way of optimizing the C/N ratio of organic materials. The use of waste paper as a carbon base has been indicated as a critical recycling opportunity especially in developing countries where only about 19% of paper is recycled with the rest of it being burnt ( Gupta and Garg, 2009 ; Mupambwa and Mnkeni, 2015 ). However, there are very few studies that have looked at the nutrient mineralization of rock phosphate, incorporated at different levels, under optimized vermicomposting conditions ( Mupambwa and Mnkeni, 2018 ).…”

Assessment of nutrient quality, heavy metals and phytotoxic properties of chicken manure on selected commercial vegetable crops

“…Before analysis, the dried chicken manure was ground to pass through a 2 mm sieve. The pH and electrical conductivity (EC) were analysed potentiometrically in deionized water at a ratio of 1:10 (w/v) as outlined by Mupambwa and Mnkeni (2015) . Total nitrogen (TN) and total carbon (TC) were determined using the dry combustion method employing a Truspec C/N auto analyser ( LECO, 2003 ).…”

Fly ash composting to improve fertiliser value – A review

“…Such information is required as it could form a basis for development of specialised microbial cocktails for effective bio-conversion of fly ash. Recent studies at the University of Fort Hare in South Africa, using E. fetida and fly ash, cow dung and waste paper mixtures indicated that a 2: 1 (cow dung-waste paper: fly ash) ratio, which gives a C: N ratio of approximately 30, may be the most appropriate, as reflected by rapid decomposition and the increase in extractable P. 50 Fly ash-cow dung compost mixtures may sometimes have less extractable P than cow dung alone. 15 This problem is attributed to microbial community modification as evidenced by very low levels of PSB in fly ash composts.…”