不同施氮量下盐渍农田向日葵冠层生长与辐射利用规律  

Sunflower Canopy Development,Radiation Absorption and Use Efficiency at Different Nitrogen Application Rates in Saline Fields

作　　者：马韬 曾文治[2] 伍靖伟[2] 丁继辉[1] 俞双恩[1] 黄介生[2] MA Tao;ZENG Wenzhi;WU Jingwei;DING Jihui;YU Shuang en;HUANG Jiesheng(College of Agricultural Sciences and Engineering,Hohai University,Nanjing 210098,China;State Key Laboratory of Water Resources and Hydropower Engineering Science,Wuhan University,Wuhan 430072,China)

机构地区：[1]河海大学农业科学与工程学院,南京210098 [2]武汉大学水资源与水电工程科学国家重点实验室,武汉430072

出　　处：《农业机械学报》2020年第12期292-303,共12页Transactions of the Chinese Society for Agricultural Machinery

基　　金：国家重点研发计划项目(2017YFC0403304);中央高校基本科研业务费专项资金项目(B200201006);国家自然科学基金项目(51879196、51879074)。

摘　　要：为了探讨盐渍农田作物冠层的生长特性及其对光能的吸收利用规律,选择盐渍化地区主要经济作物向日葵为研究对象,于2015年和2016年在内蒙古河套灌区进行了大田试验。根据0~60 cm深度土壤初始饱和浸提液电导率,设置3个盐分水平:轻度(S0:0~3 dS/m)、中度(S1:3~6 dS/m)和重度盐分胁迫(S2:大于6 dS/m),设置N0、N1、N2、N3共4个施氮量水平,施氮量分别为45、90、135、180 kg/hm^2,其中2015年试验施加N0和N2水平,2016年施加N1和N3水平。对向日葵在不同盐氮水平下的叶面积动态生长过程、消光系数、辐射截获与利用效率等指标进行监测。结果表明,盐分胁迫会抑制向日葵群体叶面积指数(CLAI)在苗期和蕾期的增长,且在N3施氮量下的影响更为明显,S1和S2水平的CLAI比S0水平分别下降了48.3%和64.4%。S1水平对冠层发展造成的影响会在营养生长停止前得到缓解,而S2水平下的向日葵在进入成熟期后才能进行一定的补偿性生长。各处理的日间光能截获率(fPAR)和辐射利用效率(RUE)均表现出从苗期开始持续上升至蕾期中后期,于花期达到峰值,在成熟期出现下降的规律,其中,S0N3处理的fPAR及其累积光合有效辐射量(IPAR)在全生育期内均高于其他处理,两年试验中的最大RUE出现在S1N3处理,达到2.26 g/MJ。分析得出,本试验所用向日葵品种的消光系数为0.729。结合修正的Logistic方程及单株最大叶面积指数与有效氮肥施用量(ENA)间的线性相关关系,建立了描述不同盐氮水平下向日葵单株LAI随归一化发展指数动态变化过程的模型。研究表明,在S1水平下,增施氮肥(N2和N3)可减轻盐分胁迫效应,促进叶片生长和光能截获,提升RUE和籽粒产量的累积;在S2水平下,增施氮肥不仅不能促进冠层发展和产量累积,而且还会降低其进入成熟期前的RUE。本研究可为在不同盐渍化水平的农田中合理施用氮肥、定量预测作物冠层发展水In order to study the characteristics of sunflower canopy development and its absorption and use of radiation in saline fields,two years of field experiments were conducted in Hetao Irrigation District of Inner Mongolia in 2015 and 2016.Three salinity levels were set according to the average ECe of 0~60 cm depth:mild(S0:0~3 dS/m),moderate(S1:3~6 dS/m)and severe(S2:>6 dS/m);the nitrogen application rates were set at four levels,referred as N0,N1,N2 and N3,which were 45 kg/hm^2,90 kg/hm^2,135 kg/hm^2 and 180 kg/hm^2,respectively.The dynamics of LAI,extinction coefficient,light interception and radiation use efficiency(RUE)of sunflower were measured under different salinity and nitrogen levels.The results showed that salt stress obviously inhibited the increase of CLAI at seedling and bud stages,and its effect were more severe under N3 treatment,which decreased the CLAI at S1 and S2 levels by 48.3%and 64.6%,respectively,compared with S0.However,the effect of S1 level on canopy development could be alleviated before the end of vegetative growth,whereas the compensatory growth of sunflower occurred after entering mature stage at S2 level.The daily fraction of light interception(fPAR)and RUE of each treatment were increased constantly from seedling to bud stage,and reached the peak value in flowering stage,and then decreased in mature stage.Among them,the fPAR and the cumulative intercepted PAR of S0N3 treatment were higher than those of the other treatments during the crop cycle,but the maximum RUE appeared in S1N3,which reached 2.26 g/MJ in the same year.The research result also slowed that the extinction coefficient of sunflower in this experiment was 0.729.By combining the modified Logistic equation with the linear correlation between LAImax and the effective nitrogen application rate(ENA),a model describing the dynamics of LAI with normalized developmental index under different salinity and nitrogen levels was established.These results proved that applying N2 and N3 rate at S1 level could alleviate salt stress,pro

关 键 词：向日葵 盐分胁迫 施氮量 冠层生长 叶面积指数 辐射利用效率 

分 类 号：S565.5[农业科学—作物学] S287