中国农业科学 ›› 2022, Vol. 55 ›› Issue (9): 1749-1762.doi: 10.3864/j.issn.0578-1752.2022.09.005

• 耕作栽培·生理生化·农业信息技术 • 上一篇    下一篇

减量施氮对套作玉米大豆叶片持绿、光合特性和系统产量的影响

李易玲1(),彭西红1,陈平1,杜青1,任俊波1,杨雪丽1,雷鹿2,雍太文1,*(),杨文钰1   

  1. 1四川农业大学农学院/农业农村部西南作物生理生态与耕作重点实验室/四川省作物带状复合种植工程技术研究中心,成都 611130
    2仁寿气象局,四川眉山 620500
  • 收稿日期:2021-07-26 修回日期:2021-09-06 出版日期:2022-05-01 发布日期:2022-05-19
  • 通讯作者: 雍太文
  • 作者简介:李易玲,E-mail: liyiling0904@qq.com
  • 基金资助:
    国家现代农业(大豆)产业技术体系建设专项(CARS-04-PS18);国家自然科学基金(31872856);国家自然科学基金(31671625)

Effects of Reducing Nitrogen Application on Leaf Stay-Green, Photosynthetic Characteristics and System Yield in Maize-Soybean Relay Strip Intercropping

LI YiLing1(),PENG XiHong1,CHEN Ping1,DU Qing1,REN JunBo1,YANG XueLi1,LEI Lu2,YONG TaiWen1,*(),YANG WenYu1   

  1. 1College of Agronomy, Sichuan Agricultural University/Key Laboratory of Crop Ecophysiology and Farming System in Southwest, Ministry of Agriculture and Rural Affairs/Sichuan Engineering Research Center for Crop Strip Intercropping System, Chengdu 611130
    2Renshou Meteorological Bureau, Meishan 620500, Sichuan
  • Received:2021-07-26 Revised:2021-09-06 Online:2022-05-01 Published:2022-05-19
  • Contact: TaiWen YONG

摘要:

【目的】探究不同种植模式和施氮水平下玉米大豆的叶片持绿、光合和系统产量特性。【方法】通过田间定位试验研究种植方式(玉米单作(MM)、大豆单作(SS)、玉米套作(IM)、大豆套作(IS))和施氮水平(不施氮(NN)、减量施氮(RN:180 kg N·hm-2)、常量施氮(CN:240 kg N·hm-2))对玉米大豆叶片持绿、光合特性以及其干物质积累和系统产量的影响。【结果】玉米产量随施氮量增加而增加,大豆产量随施氮增加先增后降;RN下,IM的籽粒干物质积累量最大,玉米大豆套作系统的总产量最高,系统生产力指数(SPI)最大。套作下各作物的叶片持绿期更长,光合特性指标均较单作稳定,且在籽粒形成期优于单作;各施氮水平下,套作处理的绿叶百分比均显著高于单作,IM的最大绿叶衰减速率出现天数比MM的分别晚7 d、5 d和1 d;IS的则比SS的分别晚7 d、0 d和11 d。相比单作,套作可以显著降低各施氮水平下玉米叶片的平均衰减速率,延长最大衰减速率出现天数,降低绿叶衰减程度。各作物的光合速率表现为套作高于单作,减量施氮高于常量施氮。玉米R2期,IM的叶片光化学淬灭系数(Qp)比MM的高12.78%,非光化学淬灭系数(NPQ)则低21.30%;NPQ随施氮水平的增加而降低,RN比NN降低了17.11%。套作SPAD值波动幅度弱于单作,且呈稳定上升趋势;玉米R2期,IM比MM高34.52%,大豆R2和R6期,IS分别比SS高10.39%、29.48%;RN的SPAD值最高,玉米R2期,IMRN处理比IMNN处理高17.46%,MMRN处理比MMNN处理高35.02%;大豆R6期,ISRN处理比ISNN和ISCN处理分别高7.71%、6.67%,SSRN处理比SSCN处理高10.03%。【结论】减量施氮下,玉米大豆套作显著延长了叶片的持绿期;花后叶片的光合速率、PSⅡ光合机构功能、叶绿素都保持在较高的水平且比单作稳定,籽粒干物质积累增强,充分发挥了玉米的生产潜力并增加了大豆产量,使得套作系统总产量显著提高。

关键词: 玉米-大豆套作, 减量施氮, 系统产量, 干物质积累, 叶片持绿, 光合作用

Abstract:

【Objective】The aim of this study was to explore the characteristics of leaf green retention, photosynthesis and system yield of maize and soybean under different planting modes and nitrogen (N) application levels.【Method】The effects of planting methods (maize monoculture (MM), soybean monoculture (SS), maize intercropping (IM), soybean intercropping (IS)) and N application levels (0 N application (NN), reduced N application (RN: 180 kg N·hm-2) and constant N application (CN: 240 kg N·hm-2)) on leaf stay-green, photosynthetic characteristics, dry matter accumulation and system yield of maize and soybean leaves were studied by field positioning experiment.【Result】The maize yield increased with the increase of N application, and the soybean yield increased first and then decreased with the increase of N application; Under RN, the seed dry matter accumulation of IM was the largest, the total yield of maize-soybean intercropping system was the highest, and the system productivity index (SPI) was the largest too. Under intercropping, the leaf green period of each crop was longer, the photosynthetic characteristics were more stable than that of monoculture, and better than that of monoculture at seed formation stage; Under all N application levels, the percentage of green leaves under intercropping treatment was significantly higher than that under monoculture. The maximum green leaf attenuation rate of IM appeared 7 d, 5 d and 1d later than that of MM, respectively, while IS was 7 d, 0 d and 11 d later than SS, respectively. Compared with monoculture, the intercropping could significantly reduce the average attenuation rate of maize leaves, prolong the days of maximum attenuation rate and reduce the attenuation degree of green leaves. The photosynthetic rate of each crop was higher under intercropping than monoculture, and the reduced N application was higher than the constant N application. At R2 stage, the photochemical quenching coefficient (QP) under IM was 12.78% higher than that under MM, and the non-photochemical quenching coefficient (NPQ) was 21.30% lower; NPQ decreased with the increase of N application level, while the ratio of RN to NN decreased by 17.11%. The fluctuation range of SPAD value of intercropping was weaker than that of monoculture, and showed a stable upward trend. In maize R2 stage, IM was 34.52% higher than MM; In soybean R2 and R6 stage, IS was 10.39% and 29.48% higher than SS, respectively, and the SPAD value of RN was the highest. At R2 stage, IMRN was 17.46% higher than IMNN, and MMRN was 35.02% higher than MMNN; in soybean R6 stage, ISRN was 7.71% and 6.67% higher than that of ISNN and ISCN, and SSRN was 10.03% higher than that of SSCN.【Conclusion】Under reduced N application condition, the maize-soybean intercropping significantly prolonged the green holding period of leaves; After flowering, the photosynthetic rate of leaves, the function of PS Ⅱ photosynthetic mechanism and chlorophyll remained at a high level were more stable than that of monoculture, and the accumulation of seed dry matter was enhanced, which gave full play to the production potential of maize and increased the yield of soybean, so that the total yield of intercropping system was significantly increased.

Key words: maize-soybean relay strip intercropping system, reducing N application, system yield, dry matter accumulation, leaf stay-green, photosynthesis