Vermicomposting: promoting healthy plant growth


The indiscriminate application of various inorganic fertilizers has triggered many soil, water and health issues around the world. Due to the extent of these concerns, various forms of organic fertilizers have since been explored.


In Guyana, the National Agricultural Research and Extension Institute (NAREI) has been conducting experiments with vermicomposting, a biotechnological process whereby earthworms convert waste materials to a nutrient rich material.

The process of vermicomposting produces a peat-like material that is rich in Nitrogen, Potassium and Phosphorus, micronutrients, plant growth hormones, enzymes and various soil microbes.


NAREI is using the California Red worm (Eisenia fetida) to carry out the experiment. The earthworms are placed in vermicomposting bins to breakdown fresh cow manure and dried leaves. They have a crucial role to play in the entire process.


They consume the organic waste reducing the volume by 40-60%. An earthworm consumes materials similar to its body weight, and produces a cast (poop) that weighs roughly 50 percent of the materials consumed in a day. Their casts contain eight times as many micro-organisms as their feed, which promotes healthy plant growth. The casts do not contain any disease pathogens since the pathogenic bacteria are reliably killed in the worms’ gut.

What are the nutrients vermicompost provides?

Parameter Quantity Obtained
pH 5.80
Organic content % 5.18
Total N % 0.91
Ca (mg/kg) 1.66
Mg (mg/kg) 10.55
K (mg/kg) 6.71
P (ppm) 102
Cu (ppm) 0.22
Mn (ppm) 40.6
Fe (ppm) 5.11
Zn (ppm) 28.8



What are the benefits of using vermicompost?

  1. Enhances plant growth
  2. suppresses diseases in plants
  3. Increases porosity and microbial activity in soil
  4. improves water retention and aeration
  5. Decreases the amount of waste going to landfills and in so doing benefits the environment
  6. Lends support to the quest in the greening of Guyana’s agricultural sector.


Cognizant of these advantages, NAREI is trying to make plant seedling substrate to substitute for imported promix (a substrate that is used by most seedling setters). The vermicompost is being tested different boxes containing each of the following: coconut coir, charcoal, paddy shell and sandy type soils. The objective is to determine which one will have the physical and chemical properties when added to mychorriza to promote healthy plant growth.

How vermicomposting is done?

Fresh cow manure should be obtained and placed into an appropriate worm bin to a depth of 6-8 inches. A thin layer of dried leaves is added at the top. The California Red worms are then placed on this layer, followed by a layer of dried grass.

The bin should be continually monitored and watered every other day, or as required. When all the cow manure is converted to vermicompost, a process that usually takes two to three months, the bin should be emptied and refilled with fresh cow manure. It should be noted that an appropriate cover or shed be provided for a worm bin to prevent direct exposure to sunlight and other environmental factors.

What can vermicompost be used for?


  1. As a seed starting boost that helps support the young plants’ growth.
  2. As a form of organic fertilizer, thereby reducing the need for chemical fertilizers.
  3. As a soil amendment.