<p>In order to ensure food security for the future, finding optimal agricultural management in the shadow of significant impact of climate changes on crops is needed. This research related to nutritional problems under effect of future climate changes on rice, at four levels of nitrogen application treatments (0, 60, 90 and 120&#xa0;kg/ha, which are nominated as N0, N1, N2 and N3 treatments, respectively) and three planting densities (20 × 20&#xa0;cm, 30 × 16&#xa0;cm, 30 × 14&#xa0;cm, which are nominated as D1, D2 and D3 treatments, respectively) and two CO₂ concentration scenario (RCP2.6 and RCP6.0) at 2044 and 2064, was conducted in northern part of Iran, using Aquacrop model. The introduced polynomial equation increased the accuracy of the relationship between leaf area index and canopy cover with an average error of 16%. With the increase in fertilizer level and planting density, crop production increased, with observed maximum and minimum yields of 7 and 3.7 t/ha for N3D1 and N0D2 treatments, respectively. It was observed that the soil fertility stress led to up to 55% reduction in biomass. It was observed that during the rice growth season, the climate of the region shifts to a semi-arid state with a drought index between 0.2 and 0.3. By increasing temperature and CO₂ concentration, the soil fertility stress was also increased with the highest value of 45.5% for RCP6.0 scenario in 2064. There is a possibility of temperature stress in future years which causes stomata closure and early senescence, so in our work a maximum of 2% temperature stress was observed in 2064, which led to a 5% decrease in the yield. The water requirement of the crop increased from 305&#xa0;mm in the base year to 322&#xa0;mm in 2064.Both WP* and WUE were increased with increasing temperature and CO₂, with the highest values of 26&#xa0;g/cm² and 2.56&#xa0;kg/m3, respectively, for RCP6.0 in 2064.</p>