The Effect of Humic Acid and Nitrogen Fertilization on Nutrient Content of Lettuce

In this study, effects of humic acid and nitrogen fertilizations on the nutrient contents of two different lettuce plants were investigated. For this purpose, 0-400-800-1200 mg kg-1 doses of two liquid humic acids and ammonium nitrate and urea fertilizers were applied. According to the results of the investigation, while the highest fresh and dry weight in Model lettuce cultivar was obtained from 800 mg kg-1 humic acid and ammonium nitrate fertilizer application, in Carmesi lettuce cultivar 800 and 400 mg kg-1 was obtained from urea and ammonium nitrate fertilizer. The K content of the plant generally increased until 800 mg kg-1, and Fe content increased until 800-1200 mg kg-1 humic acid doses. It was determined that the total N and nitrate and Ca, Mn, Zn and Cu contents of the plant increased regularly with the dose, while the Mg content decreased regularly.