Local nitrogen application increases maize post-silking nitrogen uptake of responsive genotypes via enhanced deep root growth  

作　　者：CHEN Zhe REN Wei YI Xia LI Qiang CAI Hong-guang Farhan ALI YUAN Li-xing MI Guo-hua PAN Qing-chun CHEN Fan-jun 

机构地区：[1]College of Resources and Environmental Sciences/National Academy of Agriculture Green Development/Key Laboratory of Plant-Soil Interactions,Ministry of Education,China Agricultural University,Beijing 100193,P.R.China [2]Sanya Institute of China Agricultural University,Sanya 572025,P.R.China [3]Institute of Agricultural Resource and Environment,Jilin Academy of Agricultural Sciences,Changchun 130033,P.R.China [4]Cereal Crops Research Institute,Pirsabak Nowshera 24110,Pakistan

出　　处：《Journal of Integrative Agriculture》2023年第1期235-250,共16页农业科学学报（英文版）

基　　金：supported by the Hainan Provincial Natural Science Foundation of China(321CXTD443);the National Natural Science Foundation of China(31972485 and 31971948).

摘　　要：Nitrogen(N)is unevenly distributed throughout the soil and plant roots proliferate in N-rich soil patches.However,the relationship between the root response to localized N supply and maize N uptake efficiency among different genotypes is unclear.In this study,four maize varieties were evaluated to explore genotypic differences in the root response to local N application in relation to N uptake.A split-root system was established for hydroponically-grown plants and two methods of local N application(local banding and local dotting)were examined in the field.Genotypic differences in the root length response to N were highly correlated between the hydroponic and field conditions(r>0.99).Genotypes showing high response to N,ZD958,XY335 and XF32D22,showed 50‒63%longer lateral root length and 36‒53%greater root biomass in N-rich regions under hydroponic conditions,while the LY13 genotype did not respond to N.Under field conditions,the root length of the high-response genotypes was found to increase by 66‒75%at 40‒60 cm soil depth,while LY13 showed smaller changes in root length.In addition,local N application increased N uptake at the post-silking stage by 16‒88%in the high-response genotypes and increased the grain yield of ZD958 by 10‒12%.Moreover,yield was positively correlated with root length at 40‒60 cm soil depth(r=0.39).We conclude that local fertilization should be used for high-response genotypes,which can be rapidly identified at the seedling stage,and selection for“local-N responsive roots”can be a promising trait in maize breeding for high nitrogen uptake efficiency.

关 键 词：genotypic difference local nitrogen MAIZE nitrogen efficient root 

分 类 号：S513[农业科学—作物学]