种植密度对夏玉米根系特性及氮肥吸收的影响  

Effects of Planting Density on Root Characteristics and Nitrogen Uptake in Summer Maize

作　　者：石德杨[1,2] 李艳红[1] 夏德军 张吉旺[1] 刘鹏[1,3] 赵斌[1] 董树亭[1] SHI DeYang LI YanHonga XIA DeJun ZHANG JiWang LIU Peng ZHAO Bin DONG ShuTing(College of Agronomy, Shandong Agricultural University/State Key Laboratory of Crop Biology, Tai ＇an 271018, Shandong Institute of Maize and Oil Crops, Yantai Academy of Agricultural Sciences, Yantai 265500, Shandong Maize Innovation Team of Shandong Modern Agricultural Industry Technology System, Yantai 265500, Shandong)

机构地区：[1]山东农业大学农学院/作物生物学国家重点实验室,山东泰安271018 [2]烟台市农业科学院玉米与油料研究所,山东烟台265500 [3]山东省现代农业产业技术体系玉米创新团队,山东烟台265500

出　　处：《中国农业科学》2017年第11期2006-2017,共12页Scientia Agricultura Sinica

基　　金：国家自然科学基金(31171497);"973"计划(2011CB100105);国家重大基础研究(201203096);国家粮食丰产科技工程项目(2011BAD16B09);山东省现代农业产业技术体系建设项目(SDAIT-02-15)

摘　　要：【目的】玉米是中国第一大粮食作物,在国家粮食安全中具有举足轻重的作用。选用耐密型品种,增加种植密度是现在玉米获得高产的主要措施之一。然而,高密度种植加剧了玉米生长空间的压力,导致单株生长受到抑制,单株产量降低。根系作为吸收土壤水分与养分的主要器官,其生长受密植条件抑制。研究夏玉米品种根系特性对密度响应的基因型差异,探明密植条件下耐密型夏玉米根系特性与氮素吸收、利用的关系,为耐密型夏玉米品种的根系改良及密植条件下养分与水分管理提供依据。【方法】试验于2014—2015年在山东农业大学黄淮海区域玉米技术创新中心进行,以耐密型品种郑单958(ZD958)和不耐密型品种鲁单981(LD981)为试验材料,采用土柱栽培与^(15)N标记技术相结合的技术手段,研究不同种植密度下(D1,52 500 plants/hm^2与D2,82 500 plants/hm^2),不同耐密型品种根系性状及氮素吸收利用情况对种植密度的响应。【结果】增加种植密度可显著提高夏玉米籽粒产量,但两品种单株籽粒产量均显著降低。两品种根系生物量、根长、根系表面积、根系活性吸收面积均随种植密度的增加而降低;D1条件下,LD981根系各项指标生育前期高于ZD958,乳熟期后均低于或显著低于ZD958。D2条件下,两品种根系各项指标生育前期差异不显著,而生育后期LD981显著低于ZD958;地上部单株绿叶面积与穗位叶净光合速率受基因型及密度影响,变化趋势与根系一致。两品种根冠质量比受密度增加影响差异不显著,但根冠活性面积比显著降低;增加种植密度两品种单株氮素积累量及氮利用效率显著降低,肥料氮回收率、氮肥偏生产力均显著提高,但肥料氮所占植株氮素积累量的比例不受密度变化影响;D2下ZD958植株肥料氮含量、肥料氮所占比例、肥料氮回收率及氮肥偏生产力显著高于LD981。【结论】耐密�【Objective】Maize is the first food crop in China,which plays an important role in national food security.Using density-tolerance hybrids and increasing plant density is one of the primary measures to achieve high yields of maize in modern times.However,the high planting density increased the pressure of maize growth space,resulting in the growth of single plant inhibited and the yield per plant decreased,at the same time,as the major organ to absorb moisture and nutrients from soil,the roots＇ growth can be inhibited by high plant density.To ascertain the relationship between the root characteristics of density-tolerance hybrids and grain yield,and nitrogen utilization under high plant density is the base of studying the genotype differences of root characteristics of different summer maize hybrids to plant density,and which is significant for root improvement of density-intolerance hybrids and management of nutrients and moisture under high planting density.【Method】This experiment was conducted during 2014-2015 at the Huanghuaihai Regional Corn Research Center of Shandong Agricultural University.With Zhengdan 958（ZD958,density-tolerance hybrid） and Ludan 981（LD981,density-intolerance hybrid） as the experimental materials,using the soil column culture in combination with the ^（15）N-labeling technique,the responses of root characteristics,as well as nitrogen uptake and utilization,of different density-tolerance varieties to increased density were investigated at two planting densities（D1,52 500 plants/hm^2 and D2,82 500 plants/hm^2）.【Result】Grain yield of maize significantly increased with the increase of plant density,while the grain yield per plant of both hybrids significantly reduced.Over the growing process of both hybrids,the root biomass,length,surface area and active absorbing area of both hybrids were decreased with the increase of plant density.In D1 treatment,all root indicators of LD981 were higher than those of ZD958 at early growth stage but then turned to be lower or sig

关 键 词：夏玉米 耐密型品种 密度 土柱 根系特性 15N示踪 

分 类 号：S513[农业科学—作物学]