Effects of Partial Root-Zone Irrigation on the Water Use Efficiency and Root Water and Nitrate Uptake of Corn

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.