The results observed in this study are consistent with previous work of Molla et al

The results observed in this study are consistent with previous work of Molla et al. (2001) and they reported that significant reduction in total organic carbon content after microbial inoculation during composting. In this study there was a significant difference among the composting and vermicomposting treatments for TOC probably due to different rate of enzyme activity related to carbon mineralization. Hence, the activities of enzyme related to the organic matter decomposition in the treatments directly related to the substrate quality used for microbial composting. Increase in nitrogen content in the compost obtained on inoculation of lignolytic fungi (T. viridae and P. chrysosporium) in the present study, might be due to enhanced decomposition of the organic matter by these fungi leading to decrease in the organic carbon content.
4.1.4. Total kjeldhal nitrogen (TKN)
The difference in the TKN content of the compost obtained from treatment T6 was statistically significant. This confirms that if inoculations of fungal consortium into PD and BG in 1:1 mixture would have antagonistic impact on the TKN content of the compost on 60 and 90 days. The increase in TKN concentration of microbial inoculated treatments can be attributed as a consequence of strong degradation of substrates material by the inoculated microorganisms. In the present study, the maximum increase in TKN content was observed with the addition of microbial consortium. The slight decreased TKN content after 60 days in all treatments may be due to loss of nitrogen in the form of NH3 with progressive composting. According to Benitez et al. (1999) the hydrolytic enzyme production, which plays an important role in C and N cycle in waste decomposition system, is drastically influenced by the availability of easily degradable organic compounds in the substrate. Nakasaki et al. (2005) reported that the increase in the TKN content at the period of composting process was mainly due to the concentration effect of the substrate material.
4.1.5. C:N ratio
The C:N ratio is an important parameter to indicate the compost maturity, which may generally be affected by variations of the organic matter and its characteristics. C:N ratio of the compost material equal to or less than 25 is the standard for mature compost. In the present study, C:N ratio of the substrate material indicated a drastic change during composting process. The C:N ratio usually shows a decreasing tendency as the composting progresses. However, the maximum reduced C:N ratio was recorded in the T6 during 30 and 60 days of composting, which was significantly superior over other treatments. In the previous studies suggested that, higher C:N ratio would cause nitrogen to volatize thus reducing the nitrogen content, whereas lower C:N ratios would release a large quantity of soluble basic salts thus assembly the soil to affect the plant growth (Raut et al., 2008). Similar observations have been reported by Bernal et al. (1998) and they concluded that a decrease in C:N ratio implies an increase in the degree of humification of organic matter. Chang et al. (2006) have reported that the C:N ratio of mature compost should be equal to or less than 25. Higher C:N ratios would cause nitrogen to volatize thus reducing the nitrogen content while lower C:N ratios would release a large quantity of soluble basic salt thus making the soil to affect the plant growth (Raut et al., 2008). Therefore, all the fungal inoculated treatments with different turning frequency reached maturity after 30 days, than normal compost, due to slow rate of decomposition.
4.1.6. Total phosphorus (TP)
The increase in TP during composting is may be due to mineralization and mobilization of phosphorus by bacterial and phosphate activity of microorganisms as reported by other researchers (Edwards and Lofty, 1972). In the present study, increase in TP in all treatments after 60 days was probably due to the mineralization of organic P and consumption by the microbes (Huang et al., 2004). Therefore it may be concluded that acid production during organic matter decomposition by the inoculated fungal species is the major mechanism for solubilisation of insoluble phosphorus and also the presence of large number of micro?ora in the initial substrate might play an important role in increasing P content in the process of composting.
4.1.7. Total Potassium (TK)
The TK of all the treatments (T1-T6) increased gradually up to 60 days and then decreased until the end of composting period. The previous studies suggested that microorganism processed waste material contains higher concentration of exchangeable K due to enhanced microbial activity during the microbial composting process, which consequently enhances the rate of mineralization (Suthar, 2007). In the present study, at the end of composting, the TK content was higher in T6. The higher TK content of compost showed that the better nutrient levels of higher concentration compared to natural compost. This is probably due to higher mineralization rate as result of enhanced microbial and enzyme activities leading to decrease in volume of the material (Anandavalli et al., 1998; Imam and Sharanappa 2002). On the contrary, in the present study decreased in TK content after 60 days in all the treatments may be due to leaching of soluble potassium by excess water (Gupta et al., 2007).
4.1.8. Micro nutrients
In the present study, a significant difference in Ca, Na and Mg was observed during the microbial composting of PD with BG in all the treatments. The fungal inoculated treatments showed more concentration of available forms of Ca, Na and Mg than experimental control. The maximum increase in Ca, Na and Mg was observed on 60th day and slightly decline on 90th day of composting. Therefore, the microbial inoculated composting plays an important role in microbial- mediated nutrient mineralization in wastes. In general, microorganism plays an important role in transformation of plant metabolites into more available forms of Ca, Na, and Mg content, which can be further metabolized by microbial communities associated with compost (Dominguez and Edwards , 2004.)


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