| With the development of modern facility agriculture, the industrial seedling has become an integral part of vegetable gardening industry, and nursery substrate is an important material. Traditional nursery substrate based on peat, exploitation of which would not only destroy wetland ecosystems, but cause massive release of carbon resulting in adverse effects on the environment. As a kind of growth substrate substituting for peat, vermicompost has drawn wide attention due to its fine physical structure, and the capability of absorbing and holding nutrient.In this paper, nursery substrate was made by vermicompost, clay, vermiculite, and perlite, measuring the growth parameters of tomato as well as nutrient characteristics, pH and EC after nursery under greenhouse and laboratory conditions. This paper aimed at providing a scientific basis for special tomato nursery vermicompost-formulated substrate. Through these studies above, we could draw some conclusions as follows:1) The total porosity, water porosity, aeration porosity, air/water of vermicompost were larger than market substrates (CK), while the lump feature and bulk density were lower. The effect of vermicompost on plant height, root length, root fresh weight and dry weight, root-top ratio, nursery index were better than CK. After nursery, the total N, total P, nitrate N, ammonia N, available P, available K, total carbon, inorganic carbon, total organic carbon and organic matter content, as well as EC of vermicompost were higher than CK, but pH of vermicompost was lower.2) Addition of clay into vermicompost increased the lump feature and bulk density of substrate, but decreased water porosity. Addition of vermiculite or perlite into vermicompost could increase the total porosity and water porosity. The total porosity, water porosity, aeration porosity, air/water of the substrate (16:1:1, vermicompost:clay:perlite, v:v) were higher, as well as the lump feature was better, while bulk density was smaller.3) The substrate formulated by vermicompost and clay decreased plant height, root length, root volume and numbers of tomato seeding, but increased root diameter. The substrate (16:1, vermicompost:vermiculite, v:v) had more advantageous in promoting the enlarging of root surface area, root volume, root diameter, root-top ratio, G value, seedling index. The substrate (16:1, vermicompost:perlite, v:v) was beneficial to the enlarging of root diameter, root volume, root fresh (dry) weight, root-top ratio and seedling index. Addition of clay and perlite together increased root diameter and shoot fresh (dry) weight. Addition of clay and vermiculite together increased root volume and shoot fresh (dry) weight.4) Addition of clay reduced the content of total N, total P, nitrate N, ammonia N, available P, available K, total carbon, inorganic carbon, total organic carbon and organic matter and EC value in substrate after nursery,. Addition of vermiculite reduced the content of total carbon, inorganic carbon, total organic carbon, organic matter and EC, but enhanced pH. Vermicompost added with low proportion of perlite (16:1, vermicompost:perlite, v:v) and high proportion (2:1, vermicompost:perlite, v:v) reduced the content of nitrate N, ammonia N, total P, total carbon, inorganic carbon, total organic carbon and organic matter. Addition of clay and perlite or vermiculite together had significant influence on enhancing the available P content. Addition of clay and vermiculite together had significant influence on enhancing the total carbon, inorganic carbon, total organic carbon content.In summary, the abilities of holding nutrient and supplying nutrient continuously in vermicompost-formulated substrate were better than that of traditional substrate. Addition of clay, vermiculite and perlite into vermicompost had significant effect on the nutrient content of substrate after nursery, as well as pH and EC. The substrate (16～8:1:1, vermicompost:clay: perlite, v:v) could be the special tomato nursery vermicompost-formulated substrate. |
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