Journal of Natural Sciences Research www.iiste.org ISSN 2224-3186 (Paper) ISSN 2225-0921 (Online) DOI: 10.7176/JNSR Vol.9, No.3, 2019 47 Plants Response to the Application of Vermicompost: A Review Bewuket Gashaw Wolkite University, College of Agriculture and Natural Resource, PO Box 07, Wolkite, Ethiopia Abstract Organic fertilizer has long been recognized in agriculture for maintaining soil fertility and used for maximizing plant growth and yield of plants. Vermicompost: organic fertilizer is now becoming an interesting approach and proven to be effective means of improving soil structure, enhancing soil fertility and increase crop yield. Plants growth is highly stimulated by vermicompost; because it contains the nutrients and other essential nutrients like phosphorus and potassium.Vermicompost can increase growth, flowering and yields of vegetable and ornamental crops, even in a small rate. The effects of vermicompost on plants are not solely attributed to the quality of mineral nutrition is provided but also to its other growth regulating components such as plant growth hormones and humic acids. Keywords: Vermicompost, soil fertility, plant growth DOI: 10.7176/JNSR/9-3-06 1. Introduction The negative effects of chemical fertilizers and pesticides have shifted the interests of researchers towards use of organic fertilizer like vermicompost which can increase the production of crops and prevent them from harmful pests without polluting the environment (Joshi et al., 2014). Vermicompost are products derived from the accelerated biological degradation of organic wastes by earthworms and microorganisms. Earthworms consume and fragment the organic wastes into finer particles by passing them through a grinding gizzard and derive their nourishment from microorganisms that grow upon them. The process accelerates the rates of decomposition of the organic matter, alter the physical and chemical properties of the material, leading to a humification effect in which the unstable organic matter is fully oxidized and stabilized (Orozco et al., 1996). The end product commonly referred to as vermicompost is greatly humified through the fragmentation of the parent organic materials by earthworm sand colonization by microorganisms (Edwards and Neuhauser; Edwards, 1998). Vermicompost are rich in bacteria, actinomycetes, fungi and cellulose-degrading bacteria (Werner and Cuevas, 1996). Tomati et al. (1983) reported that earthworm castings, obtained after sludge digestion, were rich in microorganisms, especially bacteria. Nair et al. (1997) compared the microorganisms associated with vermicompost with those in traditional composts. The vermicompost had much larger populations of bacteria (5.7 x 107), fungi (22.7 x 104) and actinomycetes (17.7 x 106) compared with those in conventional composts. Vermicompost are finely-divided mature peat-like materials with a high porosity, aeration, drainage and water- holding capacity and microbial activity which are stabilized by interactions between earthworms and microorganisms in a non-thermophilic process (Edwards and Burrows, 1988). Vermicompost contains most nutrients in plant in available forms such as nitrate, phosphates and exchangeable calcium and soluble potassium (Orozco, 1996). Vermicompost prepared from animal waste sources, usually contained more mineral elements than commercial plant growth media, and many of these elements were changed to forms more that could be readily taken up by the plants, such as nitrates, exchangeable phosphorus, and soluble potassium, calcium, and magnesium (Edwards and Burrows, 1988). Similarly, Orozco et al. (1996) reported that coffee pulp, increased the availability of nutrients such as phosphorus, calcium and magnesium, after processing by Eisenia fetida. Joshi et al. (2014) described vermicompost as an excellent soil amendment and a biocontrol agent through a number of studies along with the reasons which make it the best organic fertilizer and more eco-friendly as compared to chemical fertilizers. Therefore, the objective of this paper is to review the response of plants to the application of vermicompost. 2. Literature Review 2.1. Characteristics of vermicompost Adhikary (2012) defined vermicompost as the excreta of earthworm which are capable of improving soil health and nutrient status. Vermicompost is a process by which all types of biodegradable wastes such as farm wastes, kitchen wastes, market wastes, bio-wastes of agro based industries, livestock wastes etc. are converted while passing through the worm-gut to nutrient rich vermicompost. Vermicompost is an excellent soil additive made up of digested compost. It has higher nutritional value than traditional composts. This is due to increased rate of mineralization and degree of humification by the action of earthworms (Albanell et al. 1988). Furthermore, it has high advantage in increasing soil fertility by improving soil physical characteristics. This is because vermicompost has high porosity, aeration, drainage, and water-holding capacity (Edwards and Burrows 1988). Nutrients such as