MSc

The study on the ‘Standardization of Techniques for Production and Enrichment of Vermiwash’ was conducted at College of Horticulture, Vellanikkara, during the year 2003-2005 with the objective to standardize the substrate controlled environment for worm multiplication, to identify the enrichment techniques of vermiwash and to evaluate the efficiency of enriched vermiwash on crop and soil.

The standardization of substrate controlled environment was based on the principle of aerobic composting. For this, plastic drums of 50 litre capacity with appropriate fabrications and arrangements were taken. Agro wastes such as banana pseudostem, coconut leaf, green leaf and cow dung in different combinations were kept for pre-composting with the addition of fungal inoculums. The earthworms were inoculated @ 1000 numbers per unit. In contrast to the aerobic composting, then are no distinct stages in vermicomposting based on temperature. Microbial count for bacteria, fungi, actinomycetes, nitrogen fixers and phosphate solubilizers were observed at initial, middle and final stages respectively. The population of phosphate solubilizers were maximum in the initial stage (pH range of 6.53 to 6.84) and nitrogen fixers, in the middle stage (pH range of 7.63 to 8.11).

The earthworm population was found to be controlled by a substrate controlled criterion. Even the substrate combination containing good portion of coconut leaves becomes conducive for worm multiplication by the proper blending with succulent substrates like banana pseudostem. As the substrate combination, banana pseudostem : glyricidia leaves : coconut leaves : cowdung in the ratio 2:2:2:1 registered the least C:N ratio of 12.25 which attained maturity within 47 days, it was identified as the best substrate controlled environment for vermicompost production. The selected treatment which comprised of Banapseudostem : Greenleaf : Coconut leaf : Cowdung in the ratio 2:2:2:1 registered a pH of 7.68 and nutrient contents of 1.19, 0.36 and 0.87 per cent respectively. It had a relatively good load of microflora as the banana pseudostem favours the flourishment of the microbial and worm population.

The selected substrate combination was taken for the further enrichment techniques. An Organic Enriching Media (OEM) was prepared using neemcake, poultry manure and bonemeal. Vermiwash was collected after the compost maturity. The plain vermiwash was enriched by mixing OEM @ 10 per cent of substrate. The resultant and best enriched vermiwash registered nutrient contents of N (1.425%), P (0.096%), K (0.410%) and Zn (169.0 ppm) with a pH value of 8.01.

With respect to the crop response studies, foliar application of one per cent urea recorded the highest yield of 95.70 g pot-1. The soil application of vermiwash at 50 per cent field capacity also proved better than foliar application of vermiwash. The crude protein content was also higher in foliar application of urea as well as in soil application of vermiwash at 50 per cent field capacity. For fertigation, the vermiwash was found to be very effective on the test crop of amaranthus.