The integrated use of excreta-based vermicompost and inorganic NP fertilizer on tomato (Solanum lycopersicum L.) fruit yield, quality and soil fertility

Purpose A field study was conducted at Dire Dawa,Eastern Ethiopia, with an objective to find out an optimumcombination of inorganic (NP) fertilizer and excreta-basedvermicompost for best economic yield and quality oftomato and to assess their effect on selected physicochemicalproperties of amended soil after crop harvest.Methods The experiment consisted of eight treatmentswhere the mineral (NP) fertilizer and the excreta-basedvermicompost were combined in different proportionsbeing arranged in a completely randomized block designreplicated three times.Results Growth, yield and quality attributes of tomato aswell as the post-harvest soil nutrient status were markedlyinfluenced by the nutrient treatments. The highest valuesfor the various growth, yield and quality attributingparameters were recorded for the treatment combinationconsisting 75% of the recommended rate of NP fertilizer 11.25 ton ha-1 vermicompost (T6), this treatmentwas also observed to have the highest net benefit withacceptable economic return as well as a fairly high residualsoil nutrient status. Following this treatment, is the integrationof 50% of recommended rate of NP fertilizer 7.5ton ha-1 vermicompost (T3) which surpassed the solemineral fertilizer and vermicompost in terms of the crop’syield and its economic return.Conclusion 25–50% of the recommended rate of chemicalfertilizer can be supplemented through vermicompost.However, in order to generate more reliable information,there is a need to conduct more such studies using moreintegration ratios of these nutrient sources (NP fertilizerand vermicompost) at various soil and agro-climaticconditions.