Physicochemical properties of vermicompost-based substrate mixtures and their effects on the nutrient uptake and growth of muskmelon (Cucumis melo L.) seedlings

The effects of vermicompost (VC) on substrate chemical and physical properties, and nutrient uptake and growth of muskmelon (Cucumis melo L.) seedlings were investigated in a greenhouse experiment during the spring season of 2013. Five treatments were applied combining VC with burnt rice hulls (BRH) or coconut husk (CH) with VC at 10%, 20%, 30%, 40% and 50% (v/v). The results demonstrated that there was a significant increase in pH, electrolyte conductivity, total porosity, aeration porosity, bulk density and macronutrients of substrates with increasing VC mixture proportion, while water holding capacity, mass wetness and Zn, Mn and Cu contents were significantly reduced. Addition of VC mixture rate up to 30% significantly increased germination rate, stem diameter, leaf area and shoot weight, but not volume and weight of roots of muskmelon seedling. VC amendment did not affect the Cu and Zn contents in the shoot but significantly influenced N, P, K, Ca, Mg, Fe and Mn concentrations in the shoot. In conclusion, VC at 20% or 30% mixed with BRH and CH gave optimum conditions for muskmelon seedling performance.