Due to water scarcity in Iran, optimal utilization of the existence soil and water resources for agricultural production in the country is necessary. Field studies to investigate the effect of different management strategies on crop production are expensive and time-consuming, the crop models has been used to simulate the crop’s growth in different management conditions. The aim of this study was to determine the best scenario for water and nitrogen fertilizer management for wheat and maize production in two soil texture: clay and clay loam and two periods of time: present time (1379-1393) and future time (1394-1408). The CERES-Maize and CERES-Wheat models were used for simulation crop production. Scenarios of maize were four irrigation management: surface, sprinkler, drip-tape, and automatic irrigation, five levels of fertilizer: 0, 100, 200, 300, and 400 kg N ha -1 , two soil texture, and two periods of time. Scenarios of wheat were five irrigation management: rainfed, surface, sprinkler, drip-tape, and automatic irrigation, five levels of fertilizer contains: 0, 100, 150, 180, and 250 kg N ha -1 , two soil texture, and two periods of time. To determine the best irrigation and fertilizer management, principal component loadings as used for statistical analysis. Evaluation indexes include yield, nitrate leaching from the root zone, nitrogen uptake by plant, water use efficiency, irrigation water use efficiency, nitrogen use efficiency, and the amount of irrigation water. The results showed that the amount of dry matter per 1 mm evapotrairation in surface, sprinkler and drip-tape irrigation for maize were 20, 20.9, and 24.3 and for wheat were 9.97, 10.32 and 10.31 kg per ha, respectively. Result of the principal component loadings indicated that yield and nitrate leaching were important indexes, thus the scenarios that have the high yield and the low nitrate leaching were selected as the suitable managements. According to the management of present time for maize, the maximum yield (14 tonha -1 ) and minimum nitrate leaching (1.4 kg N ha -1 ) were occurred in clay loam soil, automatic and drip-tape irrigation, with 200 kg N ha -1 , and the maximum yield (4.5 ton per hectare) and the minimum nitrate leaching (47 kg N ha -1 ) were for wheat in clay soil, automatic and drip-tape irrigation management with 150 kg N ha -1 . The evaluation of results in future period showed that the average air temperature will increase 0.63 degrees Celsius for maize in growing season and the average air temperature will reduce 0.7 degrees Celsius in wheat growing season. So we can conclude that if current management is applied in future period, the yield of maize will be reduced 732, 1080, and 466 kg ha -1 in clay soil, and will be 109, 72 and 145 kg ha -1 in clay loam soil, for drip-tape, sprinkler, and surface irrigation management, respectively. The yield of wheat will be reduced 1081, 1000 and 1107 kg ha -1 in clay soil and will be 930, 811 and 656 in clay loam soil, for drip- tape, sprinkler and surface irrigation, respectively. So for keeping current yield, it is necessary using precision irrigation management and applying irrigation scheduling based on on-time meteorological data. Key words : Drip-tape Irrigation, Sprinkler Irrigation, Surface Irrigation, Nitrate Leaching, Irrigation Management