施氮量对直播稻郑旱10号群体特征及产量的影响

摘要

以直播稻品种郑旱10号为供试材料,设置8种施氮水平,即全生育期施氮肥(折合纯氮)0、150、180、210、240、270、300、330 kg/hm2,探讨不同氮肥水平对直播稻郑旱10号的群体特征、根系活力和产量的影响.结果表明,直播稻郑旱10号的产量随施氮量的增加先增加后降低,当施氮量为270 kg/hm2时,产量最高(10.40 t/hm2),显著高于其他施氮量处理.直播稻郑旱10号的最高分蘖数、穗数、叶面积指数、株高、叶基角均随施氮量增加而增加;但成穗率、结实率、粒叶比、透光率则均随施氮量增加而降低;穗粒数和千粒质量与产量变化趋势一致,均随施氮量的增加先增加后降低.地上部干物质量随生育期的推进呈增加趋势,叶片净光合速率、根系活力在齐穗后随生育进程推进呈降低趋势,但地上部干物质量、叶片净光合速率和根系活力同一时期处理间变化趋势与产量变化趋势一致,均随施氮量的增加先增加后降低,当施氮量为270 kg/hm2时最高.综上,当施氮量在270 kg/hm2条件下,直播稻郑旱10号的群体质量较好,根系活力最高,产量最高.%A field experiment was conducted to reveal the effects of nitrogen application rates (0,150,180,210,240,270,300,330 kg/ha)on population characteristics,root activity and grain yield of directseeded rice Zhenghan No.10.The results showed that grain yield of direct-seeded rice Zhenghan No.10 increased first and then decreased with the increasc of N application rate,the highest yield was 10.40 t/ha when N application rate was 270 kg/ha,which significantly increased compared the yields of the other treatments.The unit area of the highest tiller,panicle number,leaf area index,plant height,leaf base angle were increased with the increase of N application rate.But spike rate,seed setting rate,grain leaf ratio and light transmission rate were decreased with the increase of N application rate,grain number per panicle and 1 000-grain weight increased first and then decreased with the increase of N application rate.Shoot dry weight showed increasing trend during the whole growth period,then the net photosynthetic rate of leaf,root activity were decreased during the grain filling period.But shoot dry weight,net photosynthetic rate of leaf,root activity increased first and then decreased with the increase of N application rate,which were the highest when the nitrogen application rate was 270 kg/ha.In summary,population characteristics were better,and root activity and grain yield were the highest when N application rate was 270 kg/ha.