Vermicompost is the product of earthworm digestion and aerobic decomposition using the activities of micro- and microorganisms at room temperature. Vermicomposting, or worm composting, produces a rich organic soil amendment containing a diversity of plant nutrients and beneficial microorganisms.
By Wajeeh Ur Rehman1, Zubair Aslam1*, Ali Ahmad1, Muhammad Sajjad1, , Mamoona Jamil4, Mehwish Nadeem3
Vermicast (also called worm castings, worm humus, worm manure, or worm faces) is the end-product of the breakdown of organic matter by earthworms. These castings have been shown to contain reduced levels of contaminants and a higher saturation of nutrients than the organic materials before vermicomposting
There are several benefits for vermicomposting but the two most popular are (1) diverting organic residuals from the landfill and reducing trash collection fees and (2) creating resources from waste materials.
Scope of vermicomposting is increasing in Pakistan too. First vermicompost center in Pakistan has been established in university of Agriculture, Faisalabad. Biomass burning has a number of severe environmental consequences, including the release of greenhouse gases such as CO2, CH4, and black carbon, which cause global warming, as well as changes in hydrology and regional climate. Furthermore, it can also cause various respiratory disorders in children and adults as it produce toxic smoke. Smog is another phenomenon that is caused when smoke is mixed up with fog droplets. Smog formation has recently increased rapidly in Pakistan. One of the main reasons for smog formation in the subcontinent region is the burning of agricultural waste. This smog can cause drastic effects on human health i.e. infections in the eyes and respiratory tract.
To get rid of such problems we have to adopt new techniques to recycle agricultural wastes for its further beneficial use in sustainable agriculture. Vermicomposting is one of such techniques that use earthworms and bio-oxidation interaction to decompose organic matter that is fed to them as parent material into nutrient rich bio fertilizer.
Vermicomposting has gained popularity, as contrasted with traditional composting. Since it gives an approach to compost natural materials that is more rapidly with great attention of nutrients and therefore, progressively useful to plant mediums. Fertilizing the soil can’t be viewed as another innovation, however among the waste administration techniques it is gaining awareness as a reasonable choice for composts with financial and ecological benefits, since this procedure disposes off or decreases the chance of dispersal of pathogens, parasites and weed seeds related with direct land utilization of compost and prompts a final stabilized product which can be utilized to recover and keep up soil quality and fruitfulness.
Sustainable agriculture demands a stable output from the soil under specific climatic conditions for longer period of crop production without affecting the fertility of soil. Green revolution has increased the agriculture production, but the non-judicious use of agrochemicals and inorganic fertilizers have disturbed the soil health. Organic matter in soil has depleted due to extensive use of synthetic fertilizers and adversely affected the soil physical and chemical properties. Pakistani soils are deficient from organic matter as it contains less than 1% organic matter. For the conservation of soil productivity, at least 2% organic matter is essential. So, it is needs of hour to add soil organic amendments to restore organic matter loss in soil. Organic amendments increase soil productivity through restoring the soil physical, chemical and biological properties. Less inorganic fertilizer use efficiency with their high cost turns the farmer’s attention towards organic farming. Organic matter improves soil structure, nutrients availability, cation exchange capacity, pH, water holding capacity and microbial activity. pH of soil is influenced by the organic matter and shift in soil pH differs with nature of organic matter.
Typical earthworms that you find in your garden are not suitable for vermicomposting. These are soil-dwelling worms that do not process large amounts of food waste and don’t reproduce well in confined spaces. Instead, worms commonly known as redworms or red wigglers are preferred because they reproduce rapidly, are communal and tend to remain on the surface while feeding.
There are several species of vermicomposting worms but the most common are Eisenia fetida and E. andrei. Red wigglers are hermaphrodites having both male and female reproductive parts; however, it still requires two worms to mate with each worm donating sperm to the other worm. Eisenia fetida is best species for vermicomposting in environments like Pakistan.
Under ideal conditions, a worm bin population can double about every 2 months (4-6 weeks from cocoon to emergence and 6-8 weeks from emergence to maturity). The “band” around a worm, known as the clitellum, indicates maturity and is reproductively active. Cocoons are about the size of a match stick head, turning pearly white to brown as they develop until one to several baby worms hatch.
Climate and Temperature
Red wigglers require similar conditions as humans for growth – they prefer room temperature (21-31°C) and adequate moisture. The population of a worms is controlled through nutrient/food availability and space requirements.
They like to eat pre-composted food most of the time. For this, the food must be crushed into small pieces. This includes crop residues, cow dung, fruit peels, paper and sewage sludge. Pieces of meat, oil, grease, bones, dairy products, cat or dog waste, etc. are not recommended for vermicomposting.
Method of vermicomposting:
If you want to do vermicomposting, first dry it in the sun for one to two days to get rid of the odor and then turn it into small pieces. So that earthworms can eat it easily. Pre-compost the material for 2 weeks and maintain humidity by sprinkling water daily. After this follow the following steps:
1. Choose flat surface that is hard and do not have glass or other inert materials (plastics) on which a thick layer of soil is 0.30 m high and its area is one square m or its length depends on the present quantity of matter.
2. Wet this layer of soil by sprinkling water
3. Lay a layer about 15 cm high of the material for which vermicomposting is to be done and wet it.
4. Add earthworms to the layer in 1:50 w/w (Eathworm:material) for two months
5. Maintain moisture level by sprinkling water daily and covering it with jute bags.
6. After two months harvest the vermicompost on appearance of black granules on top of the surface. Harvesting is usually done manually by sieving.
7. After sieving collect earthworms and further use them again ur sell them
Important Things to Take Care of:
- Do composting in any shady place to avoid sun and rain.
- Moist regularly.
- Any material that needs to be composted should not be fresh.
- Dry the substance well before use and cut it into small pieces.
- About 2000 earthworms weigh one kilogram.
- About 10 kg of earthworms can convert one ton of waste into vermi-composting.
- Temperature should be between 20-30 degrees Celsius.
Authors: Wajeeh Ur Rehman1, Zubair Aslam1*, Ali Ahmad1, Muhammad Sajjad1, , Mamoona Jamil4, Mehwish Nadeem3
1Department of Agronomy, Faculty of Agriculture, University of Agriculture Faisalabad, Faisalabad, Pakistan
2Centre of Agricultural Biochemistry and Biotechnology (CABB), University of Agriculture Faisalabad, Faisalabad, Pakistan
3Department of Plant Sciences, Quaid-I-Azam University, Islamabad