Effects Of Vermicompost Substrate On Solanaceous Vegetables Seedlings

Whether the substrate can continuously provide nutrients to ensure the absorption needs in the whole growth period of seedlings is a key to cultivate strong seedlings. Vermicompost is the product of organic solid waste digested by earthworms, with the advantage of high porosity, fine ventilation and drainage performance, as well as strong water retention capacity. In this paper, effect of vermicompost substrate uniformly mixed with vermiculite, phosphate and potassium fertilizer on seedling of development of solanaceous vegetable were studied, aiming to provide and a technical guidance for selection organic, environmental and economical solanaceous seedling substrate prescription and a theoretical basis on resource utilization. The main results were as following:1 Vermicompost mixed with vermiculite (4:1, v/v) could be used as a better substrate, compared with commonly used commercial substrate, for seedling development of solanaceous vegetable.2 All tested items of the tomato seedlings raised in vermicompost substrate were obviously better that those in control substrate (CK). Of vermicompost substrate formulations, the tomato seedlings developed in addition of low amount of urea (0.5 kg/m3) had the highest fresh and dry weight of whole seedling plant, root, leaf and stem and highest strong seedling index and growth function in all seedling development stages, while in the early and middle stage of seedling development in addition of low amount of urea (0.5 kg/m3) was superior in plant height, stem diameter, leaf expandedness and leaf number; the tomato seedlings developed in addition of moderate amount of urea(1.0 kg/m3) showed highest chlorophyll content in early and middle development stage and highest stem diameter and leaf number in late stage; leaf number in early and middle stage, leaf expandedness in early and late stage and plant height in late stage of the seedlings raised in addition of high amount of urea (2.0 kg/m3) were the highest. In the middle stage, tomato seedlings in addition of low amount of urea (0.5 kg/m3) had the highest root length while those in addition of high amount of urea (2.0 kg/m3) showed highest root surface area, root diameter and root volume. Based on this study, we can conclude that: Fresh vermicompost mixed with vermiculite (4:1, v:v) and suitable amount of nitrogen fertilizer (urea) could be used as substrate in nursery bed to raise tomato seedlings and its promotive effect on seedling growth was better than the commercial substrate which is usually made from chicken feces and peat. The optimum amount of urea added to vermicompost substrate for tomato seedling development was 0.5kg/ m3.3 The capsicum seedlings developed in addition of low amount of urea (0.5 kg/m3) had the highest leaf expandedness, plant height leaf number and fresh and dry weight of whole seedling plant, leaf and stem in all seedling development stages. Plant height, stem diameter, fresh and dry weight of whole plant, fresh weight of root, stem and leaf, of the capsicum seedling in addition of moderate amount of urea(1.0 kg/m3) was higher than those of the seedlings in addition of high amount of urea (2.0 kg/m3) and CK. Data of strong seedling index, root/shoot ratio and growth function also indicated that addition of low amount of urea (0.5 kg/m3) and addition of moderate amount of urea(1.0 kg/m3)was more promising in raising strong capsicum seedlings, compared to CK. The capsicum seedlings raised in addition of low amount of urea (0.5 kg/m3) and addition of moderate amount of urea(1.0 kg/m3) had higher chlorophyll content in early stage, while those in addition of high amount of urea (2.0 kg/m3) had higher chlorophyll content in late stage. In early and middle stage, root length, surface area, diameter and volume of capsicum seedlings raised in addition of moderate amount of urea(1.0 kg/m3) were higher than those in addition of low amount of urea (0.5 kg/m3)and addition of high amount of urea (2.0 kg/m3). Over-rated nitrogen addition decreased the survival rate of capsicum seedlings. Based on this study, we can conclude that: Fresh vermicompost mixed with vermiculite (4:1, v:v) and suitable amount of nitrogen fertilizer (urea) could be used as substrate in nursery bed to raise capsicum seedlings and its promotive effect on seedling growth was better than the commercial substrate which is usually made from chicken feces and peat.. The optimum amount of urea added to vermicompost substrate for capsicum seedling development was 0.5-1.0 kg/ m3.4 All tested items including the planting percent, leaf expandedness, plant height, stem diameter, fresh and dry weight, leaf number and leaf chlorophyll content of eggplant seedlings raised in vermicompost-formulated substrate were superior to those raised in a commercial substrate (CK). Addition of low and moderate amount of urea (0.5-1.0 kg/m3) to the vermicompost showed better promotive effect on growth of aerial part and dry matter accumulation, compared with the treatment with high rate of urea (2.0 kg/m3) added. The benefiting effect of low and moderate urea addition on strong seedling index, root/shoot ratio and growth function could be detected in earlier stage of seedling development while such effect appeared later when high amount of urea was added to vermicompost. Therefore, vermicompost mixed with vermiculite (4:1, v/v) could be used as a better substrate, compared with commonly used commercial substrate, for seedling development of eggplant and optimum rate of urea added was 1.0 kg/m3 considering cost and comprehensive status of eggplant seedling growth.