摘要
为进一步提高大豆单产,探讨烯效唑(UZ)在大豆密植栽培技术中的作用,于2022—2023年设置5个种植密度(15×10^(4)、18×10^(4)、21×10^(4)、24×10^(4)和27×10^(4)株·hm^(-2)),进行喷施60 mg·L^(-1)UZ和清水处理,研究密植大豆冠层光氮分布与氮累积特征对叶面喷施UZ的响应。结果表明,随种植密度升高,上部冠层光能截获率(FIPAR)增加,而中部和下部降低,上部冠层叶片氮含量(NCC)呈先升高后降低趋势,中部和下部NCC呈降低趋势;喷施UZ降低了上部FIPAR,增加了中部FIPAR,对下部影响相对较小,且提高了冠层NCC,对中部冠层影响最大。随种植密度增加,消光系数(KL)和氮消减系数(Kb)升高,UZ处理降低了KL和Kb;未喷施UZ处理的光氮匹配系数(K_(L)/K_(b))下降,喷施UZ缩小了K_(L)/K_(b)与理想值的差距。随种植密度升高,氮最大积累量(Y_(m))和最大累积速率(V_(m))先升后降,最大积累速率出现时间(t_(m))提前(D18U60除外),快速积累持续期(T)缩短(D18U60除外);UZ处理延迟了t_(m),并延长T,同时提高了Y_(m)和Vm。KL和Kb与K_(L)/K_(b)及氮快速积累期相关特征值显著负相关,产量与Y_(m)、快速积累期起始时期(t1)、快速积累期终止时期(t_(2))、V_(m)、t_(m)和T正相关。种植密度升高增加了群体营养器官生物量和氮累积量,降低了生物量和氮的经济系数及各器官氮含量,UZ处理增加了群体生殖器官生物量和氮累积量及生物量和氮的经济系数,清水和UZ处理的大豆产量分别在18×10^(4)和21×10^(4)株·hm^(-2)时最高。总之,空间上的大豆群体冠层光氮分布影响了时间上的氮累积分配和产量形成,UZ处理通过协调冠层光氮分布来优化氮累积特性,使适宜种植密度由18×10^(4)株·hm^(-2)提高至21×10^(4)株·hm^(-2),产量提升11.9%~23.2%。
To enhance soybean yield and clarify the role of uniconazole(UZ)in dense planting systems,a field experiment was conducted in 2022−2023 with five planting densities(15×10^(4),18×10^(4),21×10^(4),24×10^(4),and 27×10^(4) plants·hm^(-2))and two UZ treatments(60 mg·L^(-1) UZ and fresh water control).The effects of UZ on canopy light and nitrogen distribution,nitrogen accumulation,and allocation characteristics were examined under varying planting densities.As planting density increased,the fraction of PAR intercepted by each canopy layer(FIPAR)in the upper canopy increased,whereas it decreased in the middle and lower canopy layers.Concurrently,nitrogen content of each canopy layer(NCC)in the upper canopy initially increased and then decreased,whereas NCC in the middle and lower canopy layers decreased.UZ application reduced FIPAR in the upper canopy but increased it in the middle canopy,with a minimal effect on the lower canopy.Moreover,UZ application significantly increased NCC,with the largest effect observed in the middle canopy.As planting density increased,both the light extinction coefficient(KL)and nitrogen reduction coefficient(Kb)increased,whereas UZ application reduced both.Without UZ application,the matching coefficient of light and nitrogen(K_(L)/K_(b))decreased as the planting density increased,whereas UZ application narrowed the gap between K_(L)/K_(b) and the ideal value.Temporally,as the planting density increased,the maximum nitrogen accumulation(Y_(m))and its maximum rate of accumulation(V_(m))initially increased and then decreased.The time reached the maximum rate of accumulation(t_(m))occurred earlier and the duration of rapid accumulation(T)shortened(excluding D18U60).UZ application delayed tm,extended T,and increased both Y_(m) and Vm.KL and Kb were negatively correlated with K_(L)/K_(b) and the eigenvalues associated with the rapid nitrogen accumulation phase and yield were positively correlated with Y_(m),starting date of rapid accumulation period(t1),terminating date of rapid accumulation period(t_(2)),V_(m),t_(m),and T.Increasing planting density promoted biomass and nitrogen accumulation in vegetative organs,but reduced the economic coefficients for biomass and nitrogen,as well as the nitrogen content in each organ.UZ application increased biomass and nitrogen accumulation in reproductive organs,as well as the economic coefficients for biomass and nitrogen.Consequently,the highest soybean yields were achieved at planting densities of 18×10^(4) plants·hm^(-2) under fresh water treatment and 21×10^(4) plants·hm^(-2) under UZ treatment.In conclusion,the spatial distribution of canopy light and nitrogen influenced the temporal dynamics of nitrogen accumulation,distribution,and yield.UZ application optimized nitrogen accumulation characteristics by coordinating canopy light and nitrogen distribution,increased the optimal planting density from 18×10^(4) to 21×10^(4) plants·hm^(-2),and raised yield by 11.9%–23.2%.
作者
张国伟
高真真
李志康
杨长琴
束红梅
杜祥备
叶凌凤
王飞
刘瑞显
ZHANG Guowei;GAO Zhenzhen;LI Zhikang;YANG Changqin;SHU Hongmei;DU Xiangbei;YE Lingfeng;WANG Fei;LIU Ruixian(Institute of Industrial Crops,Jiangsu Academy of Agricultural Sciences,Nanjing 210014,China;Institute of Crops,Anhui Academy of Agricultural Sciences,Hefei 230001,China;Modern Agricultural Research Institute,Jiangsu Agricultural Development Co.,Ltd.,Nanjing 210000,China)
出处
《中国生态农业学报(中英文)》
北大核心
2025年第12期2440-2451,共12页
Chinese Journal of Eco-Agriculture
基金
国家重点研发计划项目(2022YFD2300904)
江苏省重点研发计划项目(BE2023346)
江苏省林业科技创新与推广项目(LYKJ[2024]15)资助。
关键词
大豆
种植密度
烯效唑
冠层光氮分布
氮累积与分配特征
soybean
planting density
uniconazole
canopy light and nitrogen distribution
characteristics of nitrogen accumulation and distribution
