This study was conducted to determine the effects of different organic fertilizers on plant growth, yield, quality properties and element contents in spinach (Spinacia oleracea L.). The research was carried out under open field conditions in Bolu province. In the study, Matador spinach variety was used and seven different applications were examined. The applications were as follows: 1) Control, 2) Chicken manure, 3) Turkey manure, 4) Sheep manure, 5) Cattle manure, 6) Vermicompost and 7)

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... l fertilizer. The experiment was established in randomized complete block design with three replications. According to the research findings, significant differences were found among the applications. In general, organic fertilizer applications significantly increased yield, plant height, plant wet weight, plant dry weight, dry matter content, number of marketable leaves, nitrogen, phosphorus, sulphur and selenium contents of the plant in comparison with control and chemical fertilizer. The highest yield was determined in cattle manure application. It was observed that cattle manure increased the yield by 88.08% compared to the control and increased the yield by 41.16% compared to the chemical fertilizer. In organic fertilizer applications, heavy metal contents such as arsenic, chrome, cobalt, and nickel were found to be lower than the control and, aluminum and cadmium contents were found to be lower than chemical fertilizer. As a result, it was determined that organic fertilizers examined in the study have positive effects on plant growth, yield, quality properties and element contents of spinach and organic fertilizers can be used successfully for sustainable agriculture in spinach cultivation.