Growth and Elemental Accumulation of Tomato Seedlings Grown in Composted Solid Waste Soil Amended

Application of municipal compost to agricultural soil can be helpful to solve municipalities problem related to the ever-increasing production of waste. Compost has been identified as an alternative chemical fertilizer to increase soil fertility and crop production. In this study the capacity of the compost made from urban wastes to enhance seedling emergence grown in potting soil is investigated. Four treatments were established based on the addition of increasing quantities of composted urban wastes to soil (1:2.5, 1:5, 1:7.5, 1:10 compost to soil ratio, v/v). Physicochemical analyses of the different mixtures were made. Plant growth, biomass production, micronutrients, macronutrients, and heavy-metal contents of plant and soil were determined. The addition of compost resulted in an increase of pH, electrical conductivity of growth media, and macronutrients (N, P, K, Ca, Mg), micronutrients )Fe, Cu, Mn, Zn, B) and heavy metal (Pb, Ni, Cd, Cr, Co) of plants and growth media. The highest germination, growth rate, shoots and roots dry weight was obtained with the medium prepared by mixing ratio of 1:5 compost and soil. The mixture ratio of 1:2.5 had the lowest germination and growth of seedling. Both toxic constituents and nutrient imbalances may be responsible for the growth-inhibiting effects of the municipal compost in the treatments. The addition of compost to growth media increased plant nutrient and heavy metal contents of plants. Excessive application of municipal compost to agricultural soil may lead to deleterious effects on crops.