Determination of the effects of vermicompost applications at different rates on plant growth, quality properties and nutrient content in lettuce (Lactuca sativa L.)

This study was conducted to determine the effects of vermicompost which is an organic fertilizer increasing use in recent years applications at different rates on plant growth, some quality properties and nutrient content in the greenhouse cultivation of lettuce in Karabük conditions. The research was carried out in pots in the unheated plastic greenhouse conditions during the autumn growing season in 2017 and Maritima variety was used. Six different applications were examined in the study. The applications was as follows: 1) Control (100% Soil), 2) VK1 (97.5% Soil + 2.5% Vermicompost, w/w), 3) VK2 (95% Soil + 5% Vermicompost, w/w), 4) VK3 (90% Soil + 10% Vermicompost) 5) VK4 (80% Soil + 20% Vermicompost, w/w) and 6) TG (100% Soil + Commercial Fertilizer). The study was established in completely randomized design with 3 replications. In the study, 23 properties related to plant and quality and 24 elements were examined. According to the research findings, significant differences were found among the applications. The higher values in terms of plant height, plant wet weight, plant dry weight, number of marketable leaves and chlorophyll content were obtained from vermicompost applications compared to the control. In general, vermicompost applications were determined to increase the nitrogen, phosphorus, potassium, magnesium, calcium, sodium, iron, copper and zinc content of the plant compared to the control. In terms of heavy metals such as cadmium, cobalt, nickel and lead, vermicompost applications had lower values than control. VK1 in terms of plant wet weight and phosphorus content; all vermicompost applications (VK1, VK2, VK3 and VK4) in terms of plant height, number of marketable leaves, chlorophyll, potassium and zinc content; VK1 and VK3 in terms of nitrogen content; VK3 and VK4 in terms of calcium content; VK4 in terms of magnesium content; VK2, VK3 and VK4 in terms of iron content were found to be the most successful vermicompost applications. As a result of the study, it was determined that vermicompost applications have positive effects on plant growth, quality properties and nutrient content in lettuce. Vermicompost is thought to be a good alternative fertilizer for sustainable agriculture in lettuce cultivation.