Evaluation of nitrogen budget inputs and outputs in wheat and corn growing areas in lower Seyhan plain

Nitrogen (N) is one of the major plant nutrients extensively used in plant production, its excess and unconscious use effect an important negative role in environment and human health. Therefore, nitrogen dynamics in soils need to be studied to determine the N-budget in a broader level to control and prevent the risk factors. The plant, consequently fertilization, affected N budget has been studied in Akarsu Irrigation District of Lower Seyhan Plain (9 495 ha) of the Cukurova Region using wheat, 1st and 2nd crop corn during 2007 and 2008 hydrological years. Selected N input and output constituents (i.e. soil N, plant N, water N and rainfall N) have been determined to use in N budget of these related crops. Total of six N budgets were calculated for three crops and two years. According to the results of the research when the N budget was examined, there were 40 and 49 kg N ha-1 in wheat, 46 and 82 kg N ha-1 in 1st crop corn, and 176 and 229 kg N ha-1 in 2nd crop corn growing areas were recorded as the amount of remaining N in the system during 2007 and 2008 hydrological years. The input and output values indicate that fertilizer N, and N uptake by plant are the most important and valuable budget constituents affecting the N budget in Akarsu Irrigation District. The high amounts of nitrogen applied to soil for high yields in corn as a second crop have significantly contributed to then accumulation in the soils of the experimental field based on factors of soil and climate. Based on the overall results of this research, there may be potential risk of N pollution in the region and some input and output constituents need to be controlled and monitored periodically.