Review of Research on Vermicompost Applications in Agriculture

While excessive chemical input into agricultural lands has caused environmental problems, deteriorating crop quality, disease and pest resistance in plants, and declining soil fertility, concerns about food security and enhanced quality of agricultural products have been steadily rising in most human communities. Meanwhile, more than 60% of Iran's agricultural land is located in arid and semi-arid areas that are poor in organic matter. It is, therefore, of utmost importance to improve soil fertility by application of organic matter to soil. A major portion of the vermicompost research in the past was focused on the effects of this organic fertilizer on the performance and yield of different farm, horticultural, ornamental, and medicinal crops; mitigation of plant stresses; and soil physicochemical properties. Based on the results obtained, application of vermicompost, either alone or in combination with chemical fertilizers, at 5‒10 t/ha for medicinal plants, 20‒30% of pot volume for ornamental plants, 20‒60 t/ha for crop plants, 40‒80 t/ha every two or three years for vegetables and summer fruits, and 30‒60 t/ha every three years for fruit trees has been recommended. Application of vermicompost fertilizer seems not only to improve soil physicochemical properties but also to reduce significantly the amount of chemical fertilizers used, thereby contributing positively to sustainable crop production.