The compost prepared by using earthworms is called Vermicompost. Vermicompost is very important aspect of organic farming package. It is easy to prepare, has excellent properties and is absolutely harmless to plants. Vermicompost is a mixture of totally decomposed fine biomass particles and Vermicompost (fecal matter released by earthworms after digesting the food). Pure and good quality Vermicompost is soft, spongy, sweet smelling and dark brown in colour.
The passage of material through the earthworm guts converts the locked up minerals into available forms, which are readily assimilable by plants. This is made possible by the presence of a large number of micro floras in the guts of the earthworms. Significantly casting produced by earthworms have nearly hundred times more bacterial population than the surrounding soils. Aggregate structure of Vermicomposting is like a porous pyramid. It holds water but excess of water flows away through it. Hence Vermicompost helps to improve the soil structure.
Chemical Composition of Vermicompost
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The Basic of Vermicomposting
The growth of earthworms in organic wastes has been termed vermiculture and the processing of wastes with earthworms is known as vermicomposting. The principles behind vermicomposting are relatively simple and related to those involved in traditional composting. Certain species of earthworms can consume organic wastes very rapidly and fragment them into much finer particles, by passing them through a grinding gizzard, an organ that all earthworms possess. The earthworms derive their nourishment from the microorganisms that grow upon the organic wastes; at the same time they promote further microbial activity in the wastes, so that the fecal material, or “casts” that they produce, is much more fragmented and microbially active than the wastes the earthworms consume. During this process, the important plant nutrients that the wastes contain, particularly nitrogen, phosphorus, potassium and calcium, are released and converted, through microbial action, into forms that are much more soluble and available to pl ants than those in the parent compounds. The retention time of the waste in the earthworm is short and large quantities are passed through an average population of earthworms. In the traditional aerobic composting process, organic wastes have to be turned regularly or aerated in some way in order to maintain aerobic conditions in the waste. This may often involve extensive engineering to process the wastes as rapidly as possible on a large scale. In vermicomposting, the earthworms, which survive only under aerobic conditions, take over both the roles of turning over the waste and maintaining it in an aerobic condition, thereby lessening the need for expensive engineering.
Carbon-to-Nitrogen Ratios
Carbon and nitrogen are the two fundamental elements in composting, and their ratio (C:N) is significant. The bacteria and fungi in compost digest or “oxidize” carbon as an energy source and ingest nitrogen for protein synthesis. Carbon can be considered the “food” and nitrogen the digestive enzymes. The bulk of the organic matter should be carbon with just enough nitrogen to aid the decomposition process. The ratio should be roughly 30 parts carbon to 1 part nitrogen (30:1) by weight. Adding 3-4 kg of nitrogen material for every 100 kg of carbon should be satisfactory for efficient and rapid composting. The composting process slows if there is not enough nitrogen, and too much nitrogen may cause the generation of ammonia gas which can create unpleasant odors. Leaves are a good source of carbon; fresh grass, manures and blood meal are sources of nitrogen.
Surface Area
Decomposition by microorganisms in the compost pile takes place when the particle surfaces are in contact with air. Increasing the surface area of the material to be composted can be done by chopping, shredding, mowing, or breaking up the material. The increased surface area means that the microorganisms are able to digest more material, multiply more quickly, and generate more heat. It is not necessary to increase the surface area when composting, but doing so speeds up the process. Insects and earthworms also break down materials into smaller particles that bacteria and fungi can digest.
Aeration
The decomposition occurring in the compost pile takes up all the available oxygen. Aeration is the replacement of oxygen to the center of the compost pile where it is lacking. Efficient decomposition can only occur if sufficient oxygen is present. This is called aerobic decomposition. It can happen naturally by wind, or when air warmed by the compost process rises through the pile and causes fresh air to be drawn in from the surroundings. Composting systems or structures should incorporate adequate ventilation. Turning the compost pile is an effective means of adding oxygen and brings newly added material into contact with microbes. It can be done with a pitchfork or a shovel, or a special tool called an “aerator,” designed specifically for that purpose. If the compost pile is not aerated, it may produce an odor symptomatic of anaerobic decomposition.
Moisture
Microorganisms can only use organic molecules if they are dissolved in water, so the compost pile should have a moisture content of 40-60 percent. If the moisture content falls below 40 percent the microbial activity will slow down or become dormant. If the moisture content exceeds 60 percent, aeration is hindered, nutrients are leached out, decomposition slows, and the odor from anaerobic decomposition is emitted. The “squeeze test” is a good way to determine the moisture content of the composting materials. Squeezing a handful of material should have the moisture content of a well wrung sponge. A pile that is too wet can be turned or can be corrected by adding dry materials.
Temperature
Microorganisms generate heat as they decompose organic material. A compost pile with temperatures between 90F and 140F (32C-60C) is composting efficiently. Temperatures higher than 140F (60C) inhibit the activity of many of the most important and active organisms in the pile. Given the high temperatures required for rapid composting, the process will inevitably slow during the winter months in cold climates. Compost piles often steam in cold weather. Some microorganisms like cool temperatures and will continue the decomposition process, though at a slower pace.
The major constraint to vermicomposting is that, in contrast to traditional composting, which is a thermophilic process that can raise temperatures in the waste to more than 70C, vermicomposting systems must be maintained at temperatures below 35C. Exposure of the earthworms to temperatures above this, even for short periods, will kill them, and to avoid such overheating careful management of the wastes is required. Earthworms are active and consume organic wastes in a relatively narrow layer of 6-9 inches, close to the surface of a compost heap or bed. The key to successful vermicomposting lies in adding wastes to the instrument in successive thin layers, so that any heating that occurs does not become excessive, although it should be sufficient to maintain the activity of the earthworms at a high level of efficiency.
Almost any agricultural, urban or industrial organic wastes can be used for vermicomposting, but many need some form of preprocessing to make them acceptable to earthworms. Such preliminary treatments can involve washing, precomposting, macerating or mixing. Ideally, mixtures of several different wastes can be processed more readily than individual wastes, are easier to maintain aerobically, and result in a better product. Cattle and horse manures, wastes from the paper industry, and sewage solids and urban waste are particularly suitable for vermicomposting.
Optimal Conditions for Vermicomposting
Those species of earthworms that can be used in vermicomposting are relatively tolerant of the chemical and environmental conditions in organic waste, so that quite simple low-management windrow or bed systems have been used extensively in the past to process wastes. However, research had demonstrated quite clearly that earthworms have well-defined limits of tolerance to certain chemicals, and that the wastes are processed much more efficiently under a relatively narrow range of favorable chemical and environmental conditions. If these limits are exceeded greatly, the worms may move to more suitable zones in the waste or die, or at best, wastes are processed very slowly. In particular, earthworms are sensitive to ammonia, salts and certain other chemicals. For instance, they will die quite quickly if exposed to wastes containing more than 0.5 mg of ammonia per gram of waste and more than 0.5% salts. However, salts and ammonia can be washed out of organic wastes readily or dispersed by precomposting. Contra ry to common belief, they do not have many serious natural enemies, diseases, or predators.
The processing of organic wastes occurs most rapidly at temperatures between 15C and 25C (60F to 79F) and at moisture contents of 70% to 90%. Outside these limits, earthworm activity and productivity and the rate of waste processing falls off dramatically; for maximum efficiency, the wastes should be maintained as close to these environmental limits as possible.
Types of Vermicomposting Technology
A number of species or earthworms have been used in vermicomposting. The species most commonly used world-wide is Eisenia fetida (the tiger or brandling worm). Other suitable species include Lumbricus rubellus (the red worm), Eudrilus eugeniae (the African night-crawler), and Perionyx excavatus, an Asian species. The latter two species do well but cannot withstand low temperatures. Each species has particular favorable characteristics and it is important to choose the best species.
The traditional methods of vermiculture have been based on beds or windrows on the ground containing waste up to 18″ deep, but such methods have numerous drawbacks. They require large areas of land for large-scale production and are relatively labor-intensive, even when machinery is used for adding wastes to the beds. More importantly, such systems process wastes relatively slow. There is good evidence that a large proportion of the essential plant nutrients, that are in a relatively soluble form, are washed out and also a significant portion can volatilize during this long processing period. Such nutrient losses are undesirable, particularly in relation to groundwater pollution, and result in a poor product. Our system have used bins or larger containers named as “Swarup vermicomposting instruments”.
Benefits and Drawbacks of Vermicomposting
Vermicomposting can break down organic wastes into valuable, finely divided plant growth media with excellent porosity, aeration and water-holding capacity, rich in available nutrients with excellent plant growth characteristics. In side-by-side plant growth trials involving 25 kinds of vegetables, fruits, or ornamental plants, vermicompost outperformed both traditional composts and commercial plant growth media in almost every experiment. This may be explained partially by circumstantial evidence that vermicompost have a better structure and may contain plant growth hormones, enhanced levels of soil enzymes, and high microbial populations.
It is interesting to note that there is no foul smell during the process of compost formation. Several reasons are attributed to this phenomenon. One of the most reasonable one is that oxygen rich hemoglobin circulate through the skin of the earthworms. Earthworm emits sufficient oxygen to oxidize foul smell producing, compounds like H2S, mercaptans, skatol, etc. of the decaying wastes converting them to odorless compounds.
The major drawback of vermicompost is that the organic wastes do not go through a high temperature phase, so if wastes containing pathogens are used, they may need an additional precomposting phase or sterilization process, to ensure that the pathogens are killed, although there is considerable scientific evidence that human pathogens do not survive the vermicomposting process.
Economics and Commercial Outlets for Vermicomposts
Since vermicomposting utilizes organic wastes that cause environmental problems and are often expensive to dispose of, their utilization and conversion into useful materials has considerable environmental and economic attractions. Many of the methods available for vermicomposting cost much less than those for large-scale traditional composting and the plant growth media produced from vermicomposting usually have a much better structure and characteristics than traditional composts. Vermicompost can be marketed for high-grade horticultural use for as much as 7 t per hector, after appropriate standardization, formulation, and packaging. The more standard and well-formulated the product, the greater is its market potential.
Materials to use (and avoid)
For millions of years, worms have been hard at work breaking down organic materials and returning nutrients to the soil. By bringing the Swarup Vermicomposting Instrument to your place, you are simulating the worm’s role in nature. Though worms could eat any organic material. You can always make them happy by adding a thin layer of shredded wet newspaper over their food, or soak some cardboard, tear it into small pieces and add it.
Worms can live for about one year in the Instrument. If a worm dies in your instrument, you probably will not notice it. Since the worm’s body is about 90% water, it will shrivel up and become part of the compost rather quickly. New worms are born and others die all the time.
What Are Worm Castings?
A worm casting (also known as worm cast or vermicast) is a biologically active mound containing thousands of bacteria, enzymes, and remnants of plant materials and animal manures that were not digested by the earthworm. The composting process continues after a worm casting has been deposited. In fact, the bacterial population of a cast is much greater than the bacterial population of either ingested soil, or the earthworm�s gut. An important component of this dark mass is humus. Humus is a complicated material formed during the breakdown of organic matter. Worm castings contain a high percentage of humus. Humus helps soil particles form into clusters which create channels for the passage of air and improve its capacity to hold water. One of its components, humic acid, provides many binding sites for plant nutrients, such as calcium, iron, potassium, sulfur and phosphorus. These nutrients are stored in the humic acid molecule in a form readily available to plants, and are released when the plants require th em.
Humus is believed to aid in the prevention of harmful plant pathogens, fungi, nematodes and bacteria.
Why Are Worm Castings So Good For Plants and Gardens?
Castings contain slow release nutrients which are readily available to plants. Castings contain the plant nutrients which are secreted by the earthworms. They dissolve slowly rather than allowing intermediate nutrient leaching. The product has excellent soil structure, porosity, aeration and water retention capabilities. The product can insulate plant roots from extreme temperatures, reduce erosion and control weeds. It is odorless and consists of 100% recycled materials. The activity of the earthworm gut is like a miniature composting tube that mixes, conditions, and inoculates the residues. Moisture, pH, and microbial populations in the gut are favorably maintained for a synergistic relationship, and then a terrific end product.
Earthworm castings will not burn even the most delicate plants and all nutrients are water-soluble, making it an immediate plant food. Earthworm castings, in addition to their use as a potting soil, can be used as a mulch so that the minerals leach directly into the ground when watered. The effects of earthworm castings used in any of these ways are immediately visible. They make plants grow fast and strong. Nematodes and diseases will not ruin gardens or plants if the soil is rich enough for them to grow fast. It is the weak plant in poor soil that is destroyed by nematodes and diseases.
About the product:
- Vermicompost is a superior bioorganic manure.
- Mixes well with the soil thereby improves structure & productivity of the soil.
- Contains NPK & micronutrients (Manganese, Zinc, Iron, Molybdenum, Boron, Copper etc.).
- Increases water retention capacity of the soil & reduces soil erosion.
- Free from weeds. Contains substances like hormones, auxines, vitamin B12, antibiotics like actenomycetes and also other growth promoting compounds.
Advantages of Vermicompost
- Use of up to 3 meter depth of soil for water & plant nutrients. 10 tones of active microbes per Ha.
- Purification of ground water.
- Healthy food from healthy Soils and minimum attack of insects and pests.
- Safe food production.
- Improvement in Land structure and productivity.
- The produce is more tasty and durable.
- Produce contains more minerals and vitamins and most important LESS EXPENSES MORE PROFITS.
- Earthworm castings are the best imaginable potting soil for greenhouses or house plants, as well as gardening and farming.
What Types of Nutrients Do Worm Castings Contain?
Castings contains 5 times the available nitrogen, 7 times the available potash and 1 1/2 times more calcium than found in 15cm of good top soil. Castings are supplied with available nutrients which are water soluble and immediately available to plant life. You will find that most potting soils have nutrient life of 2-5 days. Compost made from worm castings will last up to 6 times longer than other types of potting soils. You would need 5 times as much potting soil to do the same job as the worm castings.
Worm castings are much cheaper and do a much better job. Worm castings hold 2-3 times their weight in water. That means you water less and the pot will stay damper for a longer period. Worm castings will not burn your plants; unlike using any fresh raw manures (cow, horse, etc.) which can burn root systems if it is not applied properly. The advantage of using castings is the manure passes through the worms� digestive system producing rich organic plant food and a slow releasing fertilizer, which allows for better growth.
The nutrient status of vermicompost (prepared by two species of earthworm) and farm yard manure (FYM) is shown in the table below for comparison.
| Parameters | Eisenia foetida | Perionyx excavatus | FYM |
|---|---|---|---|
| PH | 7.40 | 7.00 | 7.200 |
| Organic Carbon (%) | 27.43 | 30.31 | 12.20 |
| Total nitrogen (%) | 0.60 | 0.66 | 0.55 |
| Total phosphate (%) | 1.34 | 1.93 | 0.75 |
| Total potassium (%) | 0.40 | 0.42 | 2.30 |
| C: N ratio | 45.70 | 45.90 | 24.4 |
Firstly, there are appreciable differences in the nutrient content of vermicomposts produced by different species of earthworms. Vermicompost is thus not a single, standard material or product. On an average, vermicompost contained more C and P than FYM, it had less K and micronutrients than FYM and both had comparable contents of N. Vermicomposts generally had wide C:N ratio as compared to FYM. On the whole vermicompost can be described as being nutritionally superior to other organic manures and the unique way in which it is produced, even right in the field and at low cost makes it very attractive for practical application.
The vermicompost contains high concentration of organic material, silt, clay and is rich in many soil nutrients such as nitrogen, sulphur, potash, phosphorus, calcium, magnesium, etc. In soil, much of the phosphorus is bound in organic matter in a form that is not available to plants. Earthworms change the phosphorus into a form that the plant roots can easily absorb. The mixing action of the earthworms can also make slow-release forms of phosphorus fertilizers more readily available.
Vermicompost is also rich in growth hormones, vitamins and acts as a powerful biocide against diseases and nematodes. Earthworms also produce enzymes which break complex biomolecules present in the garbage into simple compounds which are utilized by the micro-organisms. The micro-organisms in the worms gut also produce useful compounds like antibiotics, vitamins, plant growth hormones, etc, all of which are present in its castings. The earthworms provide ideal temperature, pH and oxygen concentration for the speedy growth of useful bacteria and actinomycetes and thus has a microbial density of about 100 times greater than in surrounding soil.
Vermicompost is finely divided peat-like materials with high porosity, aeration, drainage, and water-holding capacity (Edwards & Burrows 1988). They have a vast surface area, providing strong absorbability and retention of nutrients Vermicompost contains nutrients in forms that are readily taken up by the plants such as nitrates, exchangeable phosphorus, and soluble potassium, calcium, and magnesium
Earthworm castings contain abundant essential elements plants need for healthy growth. Odorless and non-toxic, worm castings are a natural organic fertilizer that will not wash out with watering, and will not burn even delicate plants. Castings rival chemical fertilizers in their nutrient composition, providing a concentrated source of calcium, magnesium, nitrogen, phosphates and potash.
The earthworm is extremely valuable in creating topsoil and maintaining soil fertility. Earthworm castings, or excrement, are far richer in minerals than the soil which earthworms ingest.
Organic gardeners have long prized castings as an ideal soil enricher, providing everything plants need for healthy growth.
Worm castings are rich in nitrogen, calcium, magnesium, potassium and phosphorus, as well as many beneficial enzymes and bacteria.
The earthworm’s unique digestive system coats the castings with polysaccharides, providing optimum soil structure for maximum aeration and water retention.
Worm castings will not burn when applied directly to even the most delicate plants. They are very water soluble, making their nutrients immediately available as plant food.
Worm castings can be used indoors and outdoors on any and all plants, trees, and shrubs.
Each year their castings furnish a considerable amount of valuable fertilizer which may amount to more than 50 tons per acre in a rich, organic soil. It is estimated that an earthworm will produce its own weight in castings every 24 hours.
Vermiwash, a liquid fertilizer collected after the passage of water through a column of worm action is very useful as a foliar spray. Its utility in aquatic productivity and lawn maintenance is immense. The Vermiwash complex is efficient in raising of nurseries, lawns and orchids.
Using vermicompost
You can use your compost immediately, or you can store it and use it during the gardening season, or whenever. The compost can be directly mixed with your potting soil or garden soil as a soil amendment, which helps make nutrients available to plants. Or, the compost can be used as a top dressing for your indoor or outdoor plants.