不同施肥方法对双季稻区水稻产量及氮素流失的影响

Effects of different fertilization modes on rice yield and nitrogen loss in paddy soils under double cropping rice

为保障粮食安全,减少稻田生态系统氮肥投入,提高氮肥利用率和减少氮素流失成为重要的农业和环境措施。本研究在位于湖南岳阳的农业部岳阳农业环境科学观测实验站开展为期1年的早稻、晚稻田间试验,比较了不施肥(T_1)、尿素常规施肥(T_2,施N 280 kg·hm^(-2)、P_2O_5 165 kg·hm^(-2)、K_2O 120 kg·hm^(-2))、控释肥常规施用(T_3,施N 230 kg·hm^(-2)、P_2O_5 165 kg·hm^(-2)、K_2O 120 kg·hm^(-2))、高量控释肥侧条施用(T_4,施N 230 kg·hm^(-2)、P_2O_5 138 kg·hm^(-2)、K_2O 120 kg·hm^(-2))、中量控释肥侧条施用(T5,施N 180 kg·hm^(-2)、P_2O_5 123 kg·hm^(-2)、K_2O 120kg·hm^(-2))及低量控释肥侧条施用(T6,施N 140 kg·hm^(-2)、P_2O_5 123 kg·hm^(-2)、K_2O 120 kg·hm^(-2))下氮肥的养分利用率、作物产量及氮素流失情况,以期为稻田氮素合理利用提供理论依据。研究结果表明,控释肥侧条施用可有效提高水稻的产量和氮肥利用率,减少面源流失。1)在减少稻田秧苗数量和氮肥施用量的条件下,T_4处理的水稻早晚稻产量分别比T_2处理增加13.17%和4.72%,与T_3处理相比亦分别增加7.27%和1.74%;2)侧条施肥处理有效降低了稻田氮素流失量,年氮流失量为0.466~0.673 kg×hm^(-2),比常规施肥处理降低地表径流氮流失量3.54%~29.36%;3)侧条施肥有效提高了氮肥利用率,T_4处理的氮肥利用率分别是T_2、T_3处理的1.70倍和1.22倍。因此,采用合适的施肥方式、配施适量控释氮肥可获得较高的产值和收益。高量控释肥侧条施用(T_4)是本研究区域最佳的施肥模式,对实现现代化农业生产的高产高效、资源节约和生态环境保护具有重要意义。

To ensure food security,there has been an extravagant use of nitrogen(N)fertilizer in paddy fields.Both the increase in N fertilizer efficiency and reduce in N loss in paddy soils are important in agricultural management and environmental protection.Here,we investigated the effects of side bar fertilization on paddy yields,N use efficiency and N loss in paddy soils and to provide reference for improvement of rice N utilization.Six fertilization treatments were used in the study― control(T1),common fertilizers with conventional fertilization method(T2,N280kg·hm-2,P2O5165kg·hm-2,K2O120kg·hm-2),slow-release fertilizer with conventional fertilization method(T3,N230kg·hm-2,P2O5165kg·hm-2,K2O120kg·hm-2),high slow-release fertilizer plus side bar application(T4,230kg·hm-2,P2O5138kg·hm-2,K2O120kg·hm-2),medium slow-release fertilizer plus side bar application(T5,N180kg·hm-2,P2O5123kg·hm-2,K2O120kg·hm-2)and low slow-release fertilizer plus side bar application(T6,N140kg·hm-2,P2O5123kg·hm-2,K2O120kg·hm-2).The study was done in one cropping calendar at the Agricultural Environmental Sciences Observation Station in Yueyang City,Hunan Province,China.The results showed that combined application of slow release N fertilizer and side bar application method increased rice yield,promoted N utilization rate and reduced N loss in paddy fields.Particularly for T4,yields of both early and late rice increased respectively by13.17%and4.72%,and decreased rice planting density and applied N amount,compared with T2.The yields of both early and late rice under T4treatment were7.27%and1.74%higher,respectively,than that of T3treatment.Side bar fertilization significantly reduced N loss by0.466-0.673kg(N).hm-2due to surface runoff decreasing by3.54%-29.36%,compared with T2treatment.Side bar fertilization significantly increased N use efficiency.N use efficiency under T4treatment was1.70and1.22times that of T2and T3treatments,respectively.High slow-release fertilizer plus side bar application was the best fertilization mode in the study area.Our results were beneficial for improving productivity efficiency in agricultural,resources and environmental protection.