Due to water shortages and the increasing need for food in recent years, the optimization of water consumption parameters, fertilizers, and food production are essential and a priority. The aim of this study is to investigate the effect of partial root-zone irrigation (PRI) methods on corn plant characteristics. The study also tried to measure the water use efficiency (WUE) of corn in pot cultivation and provide the best method of management in the fields of irrigation and fertigation. For this purpose, three irrigation methods, including alternate partial root-zone irrigation (APRI), fixed partial root-zone irrigation (FPRI), and conventional irrigation (CI) were studied in pots, and completely randomized blocks with eight replications were carried out. Each pot was evenly separated with plastic sheets into two sub-parts of equal volume, between which no water exchange occurred. The water content of the field capacity was calculated by the weighting method. The water requirement was provided daily, equal to 95% of the field capacity water content. Parameters including shoot and root dry weight, nitrate (N) uptake, the remaining nitrate in the soil, leaf area index, and WUE during the growing season were measured and compared. According to the results, the amount of saved water using the FPRI and APRI methods compared to the CI method were 28% and 32%, respectively. The highest and lowest WUE were observed as equal to 4.88 and 3.82 g/L using the APRI and CI methods, respectively, among which the CI method had the highest yield according to the amount of utilized water. Given the statistical examinations, there was no significant difference in the nitrate level of plants between CI and APRI, and the lowest uptake was observed in FPRI. Finally, considering indicators of yield production and WUE simultaneously, the APRI method was selected as the best method of management.

Accurate estimation of reference evapotranspiration (RET) is essential for water resource management in water‐stressed regions such as the Urmia Lake basin, northwestern Iran. While RET can be readily estimated from station records, the spatial extent over which a single station's data remain reliable is seldom quantified. This study addresses this gap by developing a spatial accuracy‐radius framework that defines, for each of 24 synoptic meteorological stations in the Urmia Lake basin, the geographic extent within which its FAO Penman‐Monteith RET estimates remain reliable, using ERA5‐Land gridded data (463 points, 9 km resolution, 2010–2020) as a spatial reference. Station accuracy was assessed using the normalized root mean square error (nRMSE), and station‐specific accuracy radii were delineated based on the station with the minimum nRMSE at each point. The results show that station accuracy decreases with increasing distance from the station, and that stations located in urban and industrial areas exhibit lower reliability, consistent with the urban heat island effect and other local environmental influences. Based on this analysis, 18 of the 24 stations were identified as valid and used to define the accuracy‐radius coverage of the basin. Compared with the conventional nearest‐station approach, the proposed accuracy‐radius method increased the mean basin area with nRMSE below 0.2 from 70% to 91%, and reduced the mean basin‐wide nRMSE from 0.197 to 0.168. These findings indicate that accounting for station‐specific spatial reliability, rather than proximity alone, provides a more robust basis for meteorological station selection in hydrological modeling, agricultural planning, and sustainable water resource management.