COMMUNICATIONS IN SOIL SCIENCE AND PLANT ANALYSIS, vol.49, no.2, pp.202-214, 2018 (SCI-Expanded)
Management of nitrogen (N) fertilization for economic crop production in water-stressed areas relies heavily on irrigation. The objectives were to determine the depth distribution of mineral N (N-min) at pre-plant and post-harvest seasons and assess the residual mineral N pool as a potential source of plant-available N for irrigated corn (Zea mays L.) in southern Turkey. Pre-plant and post-harvest composite soil samples were collected randomly from farmer's fields at 0-30, 30-60 and 60-90 cm depths, respectively, analyzed for nitrate (NO3) and ammonium (NH4) concentrations, and the N-min values were correlated with corn yields and N uptake. Results showed that substantial amounts of pre-plant (76 to 94 kg N-min/ha) and post-harvest (70-78 kg N-min/ha) N-min accumulation at different soil depths. However, the N-min did not correlate with crop yields and N uptake. Results suggested that residual N-min could be the basis for recommending N fertilization to support crop production.