Paddy Husk and Pressmud as Renewable and Ecofriendly Bioinoculant Carriers

The lignite and peat are the traditional carriers used in biofertiliser industry. They are non-renewable, costly, non ecofriendly and their reservoirs limited in India. Therefore, the present work was undertaken to check and evaluate whether the agroindustry by-products viz., peanut shell, corn cob, sawdust, paddy husk, and pressmud can be used as carriers alternative to the traditional ones. Evaluation of the carriers was done by studying the survival of Burkholderia gladioli and Bacillus circulans at 28, 37 and 45°C respectively for a period of three months on a weekly basis by the viable plate count method. Physico-chemical characteristics of the agroindustry by-products showed that pressmud and paddy husk have pH 6.62 and 6.66, ash content 0.23 and 0.32% (w/w), potassium content 0.034 and 0.037% (w/w) respectively. The water-holding capacity was high in the agroindustry by-products corn cob, sawdust, peanut shell and pressmud, which was 87.09, 60.27, 70.30, 52.98% (w/w) respectively. Pressmud and paddy husk both were found to be very rich in the macro and microelements such as CaO, MnO, V, Cu, Rb, Mo, Ag, Sn, Sb, I, Ba, Hf, Hg, Ti, Th, Co, Rb, Ag, Hg, Bi and Th in comparison to Lignite. The viable count at 28°C of Burkholderia gladioli was highest in pressmud which was 2.347×10⁵ cfu/g and in case of Bacillus circulans. It was highest in paddy husk which was 2.381×10⁵ cfu/g. The viable count of Burkholderia gladioli and Bacillus circulans was also better at 37°C and 45°C in the agroindustry by-products in comparison to Lignite. Thus, pressmud and paddy husk were found to be as alternate carriers to lignite, which will be cheaper, renewable, ecofriendly, more easily available and use of them is a clean technology. Since these are the by-products of the agroindustry, their use as carrier will give a value-added product and also protect the bacterial cells from desiccation.