The Benefits of Vermicompost

Learn why more gardeners are turning toward this natural fertilizer. This alternative restores naturally occurring microbes in the soil, increases plants disease resistance, and promotes growth.

Wondering what the big deal is about vermicompost? What is it? Why use it?  Below is an article about the benefits of using this soil enricher.

The exact definition from Enclyclo: `Vermicompost` (also called `worm compost`, vermicast, worm castings, worm humus or worm manure) is the end-product of the breakdown of organic matter by some species of earthworm. Vermicompost is a nutrient-rich, natural fertilizer and soil conditioner. The process of producing vermicompost is called `vermicomposting’.

But this may be a little clearer….As worms eat the waste materials you placed in the bin (vegetable scraps, leaves, paper, and in some cases manure), they produce poop. Many people refer to this as `worm castings`. They are small grains which are dark black in color. They look very similar to coffee grounds. When this material is combined with other non-digested materials from the bin it is referred to as vermicompost. Worms are not the only creatures digesting your veggie wastes. There are beneficial microbes that also break down the materials. This leads to a very nutrient-rich mix called vermicompost (see photo 1).

Photo 1: A big scoop of worm castings after harvesting a bin.

Reasons to Vermicompost:

  • Produce free, all-natural fertilizer/soil ammendment for gardens, house plants, or lawns
  • Get healthier plants without the use of chemical fertilizers
  • Increase disease resistance in plants
  • Avoid paper and plant wastes from filling up landfill
  • Quicker composting (1/3 the time)
  • Grow your own fishing worms

Make your own natural fertilizer/Soil Ammendment
As the organisms decompose the material in the bin, they change the chemical makeup of the bedding and waste. Secretions in the worm’s intestinal tract add concentrated nutrients as the soil passes thru. Earthworm castings contain 5 to 11 times more nitrogen, phosophorus, and potassium as normal soil (vermicomposting, april 04). These are the nutrients plants need to thrive and grow.

In addition, the cooperation between the worms and microbes produce humic acid and plant growth hormones. The humic acid binds to minerals and nutrients in the soil. It protects them from being degraded by the UV rays and/or washed out of the soil. The acid “holds” them in the soil in a form which can be readily be absorbed by the plants. And lastly, the plant growth hormones cause earlier germination, larger crop yields, and much deeper root development. It is these combined affects that keep gardeners  using the worm castings in their gardens.

They can get bigger fruit and vegetables without adding any chemical fertilizer! Chemical fertilizers can be helpful to plants, but they have negative impacts in long run. First, the chemicals can burn your plant if too much is used.  But more importantly, they kill off the thousands of microorganisms and earthworms that are naturally found in the soil. This leads to poor soil quality. By using vermicompost as a soil additive, the plant gets the nutrients it needs, rich humus to hold in moisture, and the soil’s health improves (increased microbe population).

Below is a chart showing the improved conditions when adding vermicompost to normal soil. Note the high carbon, nitrogen, phosphorus, potassium, calcium, zinc and magnesium.

soil conditions

Table 1. Shows chemical comparison between vermicompost and soil (taken from “Influence of vermicompost on soil chemical and physical properties in tomato field”)

Most people think compost is compost…but this is not true. There was a study preformed comparing traditional compost (from a heap) to vermicompost (using worms). Again, you can see that the chemical makeup of the soil is better. The above mentioned elements are higher in quantity and even the pH has become more neutral. In addition the vermicompost nutrients are in an form that is easier for the plants to absorb (ex: nitrates).

In addition, vermicompost may have up to a 1000 times higher microbial population than normal compost.  Compost piles break down materials using bacteria that thrive in high temperatures. These high temperatures kill off some of the microbes.  But with vermicompost, waste is broken down aerobically at moderate temperatures. This permits a much wider spectrum of microorganisms to develop in the final product. It is these microbes that can convert nutrients in the soil to a form that is more readily absorbed by plants (Edwards, 1999).

Also, vermicompost can be generated in 1/3 the time as regular compost. This means that you can produce more compost for your garden in the same amount of time. And it improves the plant’s ability on many different levels including: seed germination, seed/plant growth, and higher productivity by plants ie. fruits and vegetables (Arancon, 2004). This study recommended vermicompost make up between 10-40% of the plant’s soil.

compost vs vermicompost

Table 2 shows comparison between normal compost and vermicompost.

On final benefit I will touch upon is that in many different studies, vermicomposts was found to helps increase a plant’s resistance to disease. The theory is that all the microbes present compete for the nutrients in the soil and make it harder for the harmful microbes to survive. By having a diverse population of microbes in the soil, diseases and harmful microbes have a harder time surviving. Wineries on the west coast use vermicompost to help prevent loss of grape vines to disease. They continue to have remarkable results. And in some cases, it has been found to repel pesky mites… but this is an area still being investigated.

So the question is now why not use vermicompost? I can’t answer that one…

Arancon, Norman. 2004. “An Interview with Dr. Norman Arancon”. In Casting Call, 9(2), August.

Edwards, C.A. 1999. “Interview with Dr. Clive Edwards”. In: Casting Call; Peter Bogdanov, Ed., VermiCo, Merlin, Oregon. 4(1), June Issue.

“Influence of vermicompost on soil chemical and physical properties in tomato field”, African Journal of Biotechnology Vol 7., pp 2397-2401, July 18, 2008.

“Vermicomposting”. Dickerson, George. Cooperative Extension Service College of Agriculture and Home Economics, New Mexico State University. April 2004

This entry was posted in Vermicomposting and tagged , , , , , . Bookmark the permalink.

One Response to The Benefits of Vermicompost

  1. Pingback: Worms in the Basement « Happenings on the Farm