PhD

The study on Calcium dynamics in substrate-wormcast-mushroom-plant continuum was conducted at College of Horticulture, Vellanikkara during October 2006 to May, 2010 with the objectives, to select a suitable organic enrichner for calcium rich wormcast production, to standardize the protocol for calcium rich wormcast production, to test the suitability of wormcast as a casing material and substrate for milky mushroom production, to evaluate the spent mushroom as source of nutrition in tomato (Lycopersicon esculentum Mill.) and to explore the contributions of different calcium rich nourishing media to soil health in a sustainable way.
In order to attain the objectives, the different experiments were done in a phased manner.
In experiment 1, the different animal and bird manures such as those of cow, pig, rabbit, goat, poultry and quail were characterized for their physico-chemical properties especially the calcium. The screening process was carried out as a rapid exploratory trial. Based on calcium content, cowdung and goat manure were selected as the promising organic enrichners for calcium rich wormcast production.
In order to standardize the protocol for calcium rich wormcast production, an incubation experiment was carried out with banana pseudostem as the substrate. Along with different levels of organic enrichners, the inorganic materials such as phosphate rock and lime were tried. The biotic agent, Eudrilus euginiae was introduced after 10 days of incubation. The temperature of the compost pile was monitored daily. The samples were drawn at fortnightly intervals and examined for various properties like pH, microbial count and earthworm biomass. Along with the determination of physico-chemical properties of compost material, the wormcast was also fractionated into humic and fulvic acids of organic matter.
Based on the calcium content, the wormcast produced in the treatment that received 50 per cent level of cow dung was selected for the succeeded experiment. In order to evaluate the best casing material, a study was undertaken in a suitably designed mushroom shed, using the mushroom strain, Calocybe indica. The trial was carried out with different casing materials, wormcast, coirpith compost, termite mud dune and soil, viz., 10, 20, 30, 40 and 50 per cent of the substrate, paddy straw. Samples were drawn at harvest for recording the morphological characters, growth attributes, yield, keeping quality, biochemical constituents and physico-chemical properties. Based on calcium content, the spent mushroom produced by the treatments with 20, 40 and 50 per cent wormcast was selected as the nutritional source for tomato.
A pot experiment was done with tomato variety, Anagha. The spent mushrooms were mixed with potting mixture at levels, 25, 50, 75 and 100 per cent of the recommended dose of vermicompost for tomato (4.5 kg pot-1). From the pot culture, it was inferred that spent mushroom at levels, 50 and 75 per cent were superior to others in terms of nutrient uptake and yield in tomato. The calcium use efficiency in terms of physiological efficiency, agronomic efficiency, recovery efficiency and factor productivity was also computed for the treatments that yielded comparatively better.
The important salient findings are as follows:
1. Cow dung is the best substrate for the production of calcium rich wormcast
2. The wormcast, coirpith compost and termite mud dune are not suitable as substrate
For milky mushroom but are suitable as casing materials.
3. Wormcast at a level of 20 per cent of substrate is the best casing material for milky
Mushroom as compared to coirpith compost, termite mud dune and soil.
4. Spent mushroom at a level of 50 per cent of recommended dose of vermicompost is
sufficient for a mean yield of 0.770 kg pot -1 in tomato.
5. There is very promising complimentality among the different calcium rich nourishing
media such as substrate, wormcast, spent mushroom and soil.
6. There is much addition of calcium from the different sources both to the
exchangeable and non-exchangeable pool of soil calcium.

Effective management of animal manures for enriched compost production, use of spent mushroom as organic manure and the utilization of wormcast for milky mushroom culture are some of the practical utilities of the study. Moreover, the vermiculture may be extended to further agripreneurship programmes.