Vermicompost

INTRODUCTION:
There is a growing realisation that vermi-composting provides the nutrients and growth enhancing hormones necessary for plant growth. The fruits, flowers and vegetables and other plant products grown using vermi-compost are reported to have better keeping quality.

PROCEES OF COMPOSTING:

The process of composting crop residues using earthworms comprise spreading the agricultural wastes and cow dung in layers as 1.5 m wide and 0.9 m high beds of required length. Earthworms are introduced in between the layers @ 350 worms per m3 of bed volume. The beds are maintained at about 40 - 50% moisture content and a temperature of 20 - 30oC by sprinkling water over the beds. The earthworms being voracious eaters consume the biodegradable matter and give out a part of the matter as excreta or vermi-castings. The vermi-casting containing nutrients are rich manure for the plants. When the commercial scale production is aimed at in addition to the cost of production, considerable amount has to be invested initially on capital items. The capital cost may work out to about Rs.1500 to Rs.2500 for every tonne of compost produced annually. The high variability in the unit capital cost is due to the fact that large units require considerable expenditure on machinery and transport particularly when the source of raw materials is away from the site of production facility and the finished product has to be transported to far off places before being marketed. However, in most of the cases, the activity is viable and bankable.

ABOUT THE WORMS:
Of about 350 species of earth worms in India with various food and burrowing habits, Eisenia fetida, Eudrilus eugeniae, Perionyx excavatius are some of the species for rearing to convert organic wastes into manure. The worms feed on any biodegradable matter ranging from coir waste to kitchen garbage and vermicomposting units are ideally suited to locations / units with generation of considerable quantities of organic wastes. One earthworm reaching reproductive age of about six weeks lays one egg capsule (containing 7 embryoes) for every 7 - 10 days. Three to seven worms emerge out of each capsule. Thus, the multiplication of worms under optimum growth conditions is very fast. The worms live for about 2 years. Fully grown worms could be separated and dried in a oven to make 'worm meal' which is a rich source of protein (70%) for use in animal feed.

Eudrilus eugeniae: also known as African night crawler, is generally lager and thicker than Eisenia fetida. It is uniform in color, often ranging from reddish to dark brown or even purplish grey. This earthworm burrow deeper in to soil compared to Eisenia fetida and also requires slightly warmer temperature for breeding conditions. It consumes organic matter but may have preferences for certain type of materials or may process them differently due to its deeper burrowing behavior. This type of worms are used in vermiculture due to its fast reproduction bheaviour. It is commonly found in tropical regions with warmer temperature.

Eisenia fetida: also known as red wiggler or red worm, is generally smaller and and more slender than Eisenia fetida. It is reddish brown coloration and found to be surface dwelling and it is found in the top layers of organic material such as heap, and also requires slightly warmer temperature for breeding conditions. It consumes wide variety of organic materials, including kitchen scraps and garden waste. This type of worms is used in vermicomposting and commonly found in temperate regions.