摘要：

为探究不同灌溉方式与氮肥运筹对双季晚稻生长发育、产量形成与氮肥利用率的影响,于2022-2023年,在湖南益阳市赫山区,以Y两优911为试材,设2种灌溉方式(W1.淹水灌溉;W2.湿润灌溉)和3种氮肥运筹(N1:基肥∶蘖肥∶穗肥=5∶3∶2;N2:基肥∶蘖肥∶穗肥=3∶4∶3,N3:基肥∶蘖肥∶穗肥∶粒肥=3∶4∶2∶1),不施氮肥为对照(CK1.淹水灌溉;CK2.湿润灌溉),测定各处理组合下水稻的叶面积指数、叶片SPAD值、干物质积累量、产量形成及氮素利用率。结果表明,与W1相比,W2处理下水稻LAI在生育前期LAI较低,生长中后期W2处理LAI整体表现较高;SPAD值以W1处理较高,但生育后期SPAD值差异不显著;在相同的灌溉条件下,与N1相比,N2、N3处理能够延缓水稻生育后期LAI与SPAD值的下降;W2处理能显著提高水稻干物质积累量,较W1处理增加6.61%~16.37%,氮肥运筹下生育前中期干物质量以N1较高,生育后期干物质量以N1、N3较高;W2模式比W1模式增产7.59%~10.47%;2种灌溉模式下均以N3处理产量表现最佳,W2N3处理要比其他处理增产3.24%~14.53%,W2N3处理虽然有效穗数较低,但穗粒数、结实率、千粒质量有所提高,从而使产量提高;2 a间,氮素总积累量、氮肥吸收利用率以W2N2与W2N3较高,氮肥农学利用率、氮肥偏生产力与氮素收获指数均为W2N3较高,氮肥生理利用率以W1N3处理较高。综上,灌溉方式和氮肥运筹显著影响水稻产量和氮素吸收利用,以W2(湿润灌溉)耦合N3(基肥∶蘖肥∶穗肥∶粒肥=3∶4∶2∶1)的氮肥运筹方式更有利于水稻干物质的积累、产量的提高和氮肥的高效利用,既能满足高产,也能起到节水的作用,为最佳水肥耦合方式。

关键词: 水稻, 灌溉方式, 氮肥运筹, 干物质, 产量, 氮肥利用率

Abstract:

In order to explore the effects of different irrigation methods and nitrogen fertilizer management on late rice growth,development,yield formation,and nitrogen use efficiency,Y Liangyou 911 was used as test material.Two irrigation methods(W1.flooded irrigation;W2.moistening irrigation) and three nitrogen fertilizer managenments base,tiller,ear and grain fertilizer ratios(N1:5∶3∶2,N2:3∶4∶3 and N3:3∶4∶2∶1) were designed.No fertilization served as the control (CK1.flooded irrigation;CK2.moistening irrigation).Leaf area index,SPAD value of rice leaves,dry matter mass,yield formation and nitrogen use efficiency were determined under each treatment combination.The results showed that compared with W1,the LAI of rice treated with W2 was lower in the early growth stage and higher in the middle and late growth stages.The SPAD value of W1 treatment was higher,but there was no significant difference in SPAD value in the late growth period.Under the same irrigation conditions,compared with N1,N2 and N3 treatments it could delay the decline of LAI and SPAD values in the late growth period of rice.W2 treatment could significantly increase rice dry matter accumulation by 6.61%-16.37% compared with W1 treatment.Under nitrogen fertilizer treatment,the dry matter mass was higher in the early and middle stages of growth with N1,and the dry matter mass was higher in the later stages with N1 and N3.The yield increase of W2 mode was 7.59%-10.47% compared with W1 mode.The yield of W2N3 treatment was 3.24%-14.53% higher than that of other treatment.Although the effective panicle number was lower in W2N3 treatment,other yield components were increased,which resulted in higher yield.During the two years,W2N2 and W2N3 had higher values of total nitrogen accumulation and nitrogen absorption efficiency,W2N3 had higher values of nitrogen agronomic utilization,nitrogen partial productivity and nitrogen harvest index,and W1N3 had the higher value of physiological nitrogen utilization.In conclusion,irrigation methods and nitrogen management significantly affect rice yield and nitrogen uptake and utilization.The W2 (moistening irrigation) coupled with N3 (base fertilizer∶tillering fertilizer∶ear fertilizer∶grain fertilizer=3∶4∶2∶1) nitrogen management method is more conducive to rice dry matter accumulation,yield improvement and efficient use of nitrogen fertilizer,which can not only meet high yield,but also play a role in water saving.It is the best coupling method of water and fertilizer.

Key words: Rice, Irrigation method, Nitrogen management, Dry matter, Yield, Nitrogen use efficiency