灌溉模式和有机肥配施对水稻产量、光合特性和氮肥利用率的影响

针对湘北地区农业水资源日益紧缺和水稻生产上滥施化学氮肥的现状，为了节约淡水资源、降低化肥用量、实现水肥协同和资源高效利用，设置2种灌溉方式(W₁：全生育期淹水灌溉；W₂：全生育期湿润灌溉)和4个施氮水平(N₀：不施氮肥；N₁：施N量150 kg/hm²，肥料为尿素氮100%;N₂：施N量150 kg/hm²，肥料为尿素氮80%+有机氮(菜枯)20%;N₃：施N量150 kg/hm²，肥料为尿素氮60%+有机氮(菜枯)40%)，分析水稻产量、光合特性、氮素代谢和氮肥利用率对灌溉模式和有机肥配施的响应规律。结果表明：与W₁相比，W₂显著增加水稻产量、氮肥利用率、净光合速率、蒸腾速率、气孔导度等；在不同施氮处理下，增加有机肥比例能显著提高产量，N₃、N₂、N₁分别比N₀

Effects of Irrigation Patterns and Combined Application of Organic Fertilizer on Rice Yield, Photosynthetic Characteristics and Nitrogen Use Efficiency

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.