施氮量对豫南直播粳稻产量及群体质量的影响

Effect of Nitrogen Application Rate on Yield and Population Quality of Direct-Seeded Japonica Rice in Southern Henan Province

为探索氮肥对豫南直播粳稻产量及群体质量的影响,以郑稻19和郑稻20为试验材料,设置8个不同施氮水平,研究不同施氮量对直播粳稻产量及其构成因素、茎蘖动态、叶面积指数、地上干物质量、根干重、氮肥利用率及经济效益的影响。试验结果表明:随施氮量的增加,产量、穗粒数、粒叶比、中后期地上干物质量、根干重和经济效益先增后降,颖花量、穗数、各生育时期叶面积指数、生育前期干物质量和根干重逐渐增加,结实率和成穗率降低。当施氮量为300 kg/hm^(2)时,郑稻19和郑稻20直播时产量最高,群体质量也较好。

Zhendao 19 and Zhengdao 20 were used as the experimental material and eight different nitrogen application levels were set to study the effects of different nitrogen application rates on the yield and its components,stem and tiller dynamics,leaf area index,aboveground dry matter quality,root dry weight,nitrogen fertilizer utilization efficiency and economic benefits of direct seeding japonica rice in southern Henan Province.The results showed that with the increase of nitrogen application,the yield,the number of grains per panicle,the ratio of grain to leaf,the aboveground dry matter mass in the middle and late stage,the root dry weight and economic benefits increased first and then decreased,the number of spikelet,the number of panicles,the leaf area index in each growth period,the aboveground dry matter mass and root dry weight in the early growth stage gradually increased,and the seed setting rate and panicle forming rate decreased.When the nitrogen application rate was 300 kg/ha,Zhengdao 19 and Zhengdao 20 had the highest yield and better population quality when they were directly seeded.