BULGARIAN JOURNAL OF AGRICULTURAL SCIENCE, cilt.15, sa.4, ss.342-347, 2009 (SCI-Expanded)
It is necessary to give a sufficient amount of nitrogen to a plant for optimum yield and high-quality production. It is economically and environmentally important to determine the right amount of nitrogen needed by plants. To determine optimum nitrogen dose in safflower production under dry conditions, data obtained from two separate field studies carried out in 2004 and 2005 have been used in this study. The relationship between the nitrogen amount applied and safflower yield was defined by using a quadratic function. Economically optimum N dose was calculated by marginal analysis. Accordingly, an economically optimum N level which is needed to be applied for a profitable production was calculated as 31.75 kg ha(-1) for 2004 and 33.75 kg ha(-1) for 2005. By using N at economically optimum level, it will prevent the environment from pollution of 48.50 kg ha(-1) N and 48.92 kg ha(-1) N according to the data for 2004 and 2005 years, respectively. In addition, it will decrease input cost by 64.51 NTL ha(-1) and 65.06 NTL ha(-1).