MSc

The study entitled “Characterization, conversion and evaluation of selected lignocellulosic biomass” was conducted during the period 2013-14 at the Department of Soil Science & Agricultural Chemistry, College of Agriculture, Vellayani. The main objectives of the study were the characterization of the lignocellulosic biomass from selected plant sources, assessment of various microbial and enzymatic sources for degrading the lignocellulosic biomass into compost and evaluation of the resultant compost for assessing its manurial value.
The experiment was completed in three stages. Representative samples of water cabbage (L. flava), coir pith, water hyacinth (E. crassipes) , and farm wastes (dried leaves and pseudostem of banana) were collected and analysed for bio-chemical composition. Water cabbage recorded 2.74 per cent N, 0.30 per cent P, 0.33 per cent K, 16.98 C:N ratio, and no detectable levels of heavy metals except Ni (0.55 ppm) and inferred as the best substrate in terms of nutrient content followed by water hyacinth, farm wastes and coir pith respectively.
The substrates were converted to composts using various inoculants viz.
T. reesei, P. sajor-caju, Composting Inoculum and commercial enzyme cocktail (cellulase/pectinase and lactase) and physico- chemical and biological characteristics were analyzed. A mixture of water cabbage and Composting Inoculum) was concluded as the best in terms of nitrogen content , cellulase activity, maturity period, C:N ratio and no detectable levels of heavy metals except Ni (0.414 ppm) followed by the mixture of Water hyacinth and Composting Inoculum had comparable N, P , K, EC , C:N ratio, and heavy metal content below the detectable limit. Considering the effect of inoculants on different substrates, Composting Inoculum was concluded as the best in terms of moisture content, EC,N, P, K, dehydrogenase activity, cellulase activity, maturity period and C:N ratio.
The resultant composts from the previous stage were evaluated for their performance as manure in a pot culture experiment with test crop amaranthus (variety - Arun). Application of 100 % N as compost water hyacinth and Composting Inoculum was noticed as the best treatment in terms of yield, plant height, number of branches, girth of stem, soil properties viz. water holding capacity, available N, available P, available K, available Mn, available Cu, bacteria population and plant content of micronutrients viz. Mn, Cu, and B. Major enzymes viz. dehydrogenase, urease and aryl sulphatase imposed significance on yield and yield attributes. Application of 100 % N as compost from water cabbage and Composting Inoculum was found to be good and on par with T13 in many of the characters. Application of various composts did not result any heavy metal accumulation in the soil
Thus it was inferred from the study that water cabbage was the best substrate in terms of their chemical composition followed by water hyacinth. water cabbage + Composting Inoculum was recorded as the best compost followed by water hyacinth + Composting Inoculum. 100 % N as compost (water hyacinth + Composting Inoculum) was noticed as the best treatment in pot culture. With regards to inoculants used on different substrates,Composting Inoculum was found to be the most effective for composting the agrowastes.