Abstract:In view of the growing shortage of agricultural water resources and the abuse of chemical nitrogen fertilizer on rice production in Northern Hunan Province, in order to save fresh water resources, reduce the dosage of chemical fertilizers, and realize the coordinated and efficient utilization of resources of water and fertilizer, two kinds of irrigation methods (W1: water irrigation in whole grow period; W2: wet irrigation in whole growth period) and four nitrogen levels (N0: no nitrogen; N1: N amount 150 kg/hm2, fertilizer urea nitrogen 100%; N2: N amount 150 kg/hm2, fertilizer urea nitrogen 80% + organic nitrogen 20%; N3: N amount 150 kg/hm2, fertilizer urea nitrogen 60% + organic nitrogen 40%) were set up in this study, and then the yields, photosynthetic characteristics, nitrogen metabolism and nitrogen use efficiencies of rice under different treatments were analyzed. The results showed that, compared with W1, W2 significantly increased yield, nitrogen use efficiency, net photosynthetic rate, transpiration rate and stomatal conductance. Under different nitrogen levels, increasing organic fertilizer ratio significantly increased yield, and N3, N2and N1increased the yield by 28.32%, 25.52% and 18.88% compared with N0, respectively. Meanwhile, the absorption efficiency, agronomic efficiency and partial productivity also in the order of N3> N2> N1; The nitrogen absorption efficiency, agronomic efficiency and partial nitrogen productivity of N3reached 78.52%, 9.77 kg/kg and 46.91 kg/kg respectively. The comprehensive scoring method showed that the best irrigation mode and organic fertilizer combination was W2N3, that is, wet irrigation with N amount 150 kg/hm2, fertilizer combination of urea nitrogen 60% + organic nitrogen 40%. The above results can provide scientific basis for water and fertilizer management for rice growing in Northern Hunan Province.