Effects of vermicomposts produced from food waste on the growth and yields of greenhouse peppers Norman Q. Arancon a, * , Clive A. Edwards a , Rola Atiyeh a , James D. Metzger b a Soil Ecology Laboratory, The Ohio State University, 400 Aronoff Laboratory, 318 W 12th Avenue, Columbus, OH 43210, USA b Horticulture and Crop Science Department, The Ohio State University, Columbus, OH 43210, USA Received 26 February 2003; received in revised form 27 October 2003; accepted 28 October 2003 Abstract Vermicomposts, produced commercially from food wastes, were substituted at a range of different concentrations into a soil-less commercial bedding plant container medium, Metro-Mix 360 (MM360), to evaluate their effects on the growth and yields of peppers in the greenhouse. Six-week-old peppers (Capsicum annum L. var. California) were transplanted into 100%, 80%, 60%, 40%, 20% or 10% MM360 substituted with 0%, 10%, 20%, 40%, 60%, 80% and 100% vermicompost. All plants were watered three times weekly with 200 ppm Peter’s Nutrient Solution from the time of transplanting up to 107 days. Peppers grown in potting mixtures containing 40% food waste vermicomposts and 60% MM360 yielded 45% more fruit weights and had 17% greater mean number of fruits than those grown in MM360 only. The mean heights, numbers of buds and numbers of flowers of peppers grown in potting mixtures containing 10–80% vermicompost although greater did not differ significantly from those of peppers grown in MM360. There were no positive correlations between the increases in pepper yields, and the amounts of mineral-N and microbial biomass-N in the potting mixtures, or the concentrations of nitrogen in the shoot tissues of peppers. Factors such as: an improvement of the physical structure of the potting medium, increases in populations of beneficial microorganisms and the potential availability of plant growth-influencing-substances produced by microorganisms in vermicomposts, could have contributed to the increased pepper yields obtained. Ó 2003 Elsevier Ltd. All rights reserved. Keywords: Food waste; Vermicomposts; Pepper; Plant growth; Yield 1. Introduction Peppers (Capsicum annum L.), which belong to the family Solanaceae, are known for their versatility as a vegetable crop and are consumed both as fresh vegeta- bles or dehydrated for spices. As with other vegetable crops, peppers are still usually grown using conventional applications of inorganic fertilizers and pesticides (Bos- land and Vostava, 2000). However a growing awareness of some of the adverse economic and environmental impacts of agrochemicals in crop production, has stim- ulated greater interest in the utilization of organic amendments such as composts or vermicomposts for crop production (Follet et al., 1981). The use of organic amendments, such as traditional thermophilic composts, has been used to increase crop productivity and yields (Bwamiki et al., 1998; Johnston et al., 1995; Maynard, 1993), and their use is usually associated with improved soil structure and enhanced soil fertility (Follet et al., 1981), increased soil microbial populations (Barakan et al., 1995) and activity (Zink and Allen, 1998; Pascual et al., 1997), and an improved moisture-holding capacity of the soil. Recently, there is increasing interest in the potential of vermicomposts, which are products of a non-thermophilic biodegrad- ation of organic materials through interactions between earthworms and microorganisms, as plant growth media and soil amendments. Vermicomposts are finely divided peat-like materials with high porosity, aeration, drain- age, water-holding capacity and microbial activity, which make them excellent soil amendments or condi- tioners (Edwards and Burrows, 1988; Atiyeh et al., 1999, 2000d; Edwards, 1998). Metro-Mix 360 is a soil-less medium prepared from vermiculite, Canadian sphagnum * Corresponding author. Tel.: +1-614-292-5483; fax: +1-614-292- 2180. E-mail address: arancon.1@osu.edu (N.Q. Arancon). 0960-8524/$ - see front matter Ó 2003 Elsevier Ltd. All rights reserved. doi:10.1016/j.biortech.2003.10.015 Bioresource Technology 93 (2004) 139–144