施氮量和移栽密度对双季杂交稻干物质生产及氮肥利用率的影响

Effects of Nitrogen Application Rate and Transplanting Density on Dry Matter Production and Nitrogen Use Efficiency of Double Cropping Hybrid Rice

【目的】研究施氮量和移栽密度对双季杂交稻干物质生产及氮肥利用率的影响。【方法】以株两优819为早稻材料、泰优398为晚稻材料,设置3种施氮量水平(早稻分别为0、120、150 kg/hm^(2),晚稻分别为0、150、225 kg/hm^(2))、3个移栽密度(早稻分别为13.3 cm×16.7 cm、13.3 cm×20.0 cm、16.7 cm×20.0 cm,晚稻分别为16.7 cm×20 cm、16.7 cm×23.3 cm、16.7 cm×26.7 cm)。【结果】增施氮肥能显著提高水稻干物质量的积累,移栽密度对干物质量影响较小,早晚稻干物质量在成熟期均以N3M1处理最高,其中早稻干物质量比其他处理增加8.81%~110.24%,晚稻较其他处理增加9.12%~117.12%。早稻N2M2处理氮肥吸收利用率最高达60.73%,晚稻N2M3处理氮肥吸收利用率最高达63.20%。增施氮肥不能显著提高对产量的贡献率,对晚稻收获指数影响也较小;早晚稻增施氮肥能显著提高水稻总氮累积量,早稻增幅为67.50%~77.03%,晚稻增幅为73.18%~115.12%;早稻各施肥处理对氮肥农学利用率和生理利用率的影响较小,晚稻减氮处理的农学利用率增幅达52.66%、生理利用率增幅达59.00%;早晚稻减氮均能提高水稻偏肥生产力,早晚稻增幅分别为15.54%、48.58%。移栽密度对早晚稻产量贡献率表现为M3处理分别比M1、M2处理高18.52%~47.22%、23.42%~35.42%;对总氮累积量、收获指数、农学利用率和偏肥生产力的影响均较小;低栽培密度可提高早稻生理利用率,增幅可达52.19%~144.14%,但对晚稻的生理利用率影响较小。【结论】N2M2、N3M3处理能使双季杂交稻保持较高的氮肥利用率和干物质积累量,且N2M2处理既能节肥也能维持较高的氮肥利用能力。

【Objective】The study was carried out to study the effects of nitrogen application rate and transplanting density on dry matter production and nitrogen use efficiency of double cropping hybrid rice.【Method】Zhuliangyou 819was used as early rice material and Taiyou 398 was used as late rice material. Three nitrogen application levels(N1,N2,N3at 0, 120,150 kg/hm^(2)for early rice and N1,N2,N3 at 0, 150 and 225 kg/hm^(2)for late rice,respectively) and three transplanting densities(M1, M2, M3 at 13.3 cm×16.7 cm, 13.3 cm×20.0 cm, 16.7 cm×20.0 cm for early rice and M1, M2, M3 at 16.7 cm×20 cm, 16.7cm×23.3 cm, 16.7cm×26.7cm for late rice, respectively).【Result】Increasing nitrogen fertilizer can significantly improve the accumulation of dry matter quality of rice, and the effect of transplanting density on dry matter quality is small. The dry matter quality of early and late rice is the highest in N3M1 treatment at maturity, in which the dry matter quality of early rice is 8.81%-110.24% higher than that of other treatments, and that of late rice is 9.12%-117.12% higher than that of other treatments. The nitrogen uptake and utilization efficiency of early rice N2M2 treatment was up to 60.73%, and that of late rice N2M3 treatment was up to 63.20%. Increasing nitrogen fertilizer could not significantly improve the contribution rate to yield, and had little effect on the harvest index of late rice;Increasing nitrogen fertilizer application in early and late rice could significantly increase the total nitrogen accumulation of rice, with an increase of 67.50%-77.03% in early rice and 73.18%-115.12% in late rice;Each fertilization treatment of early rice had little effect on the agronomic and physiological utilization efficiency of nitrogen fertilizer.The increase of agronomic and physiological utilization efficiency of nitrogen reduction treatment of late rice was 52.66% and 59.00%;Nitrogen reduction in early and late rice can improve the partial fertilizer productivity of rice, and the growth rates of early and late rice are 15.54% and 48.58% respectively. The contribution rates of transplanting density to the yield of early and late rice were 18.52%-47.22% and 23.42%-35.42% higher in M3 treatment than in M1 and M2 treatment, respectively;It had little effect on total nitrogen accumulation, harvest index, agronomic utilization rate and partial fertilizer productivity;Low planting density can improve the physiological utilization rate of early rice, with an increase of 52.19%-144.14%, but it has little effect on the physiological utilization rate of late rice.【Conclusion】Therefore, N2M2 and N3M3 treatment can maintain high nitrogen use efficiency and dry matter accumulation of double cropping hybrid rice, and N2M2 treatment can save fertilizer and maintain high nitrogen use ability.