Validation of a Critical Nitrogen Curve for Summer Maize in the North China Plain  

作　　者：YUE Shan-Chao SUN Fu-Lai MENG Qing-Feng ZHAO Rong-Fang LI Fei CHEN Xin-Ping ZHANG Fu-Suo CUI Zhen-Ling 

机构地区：[1]College of Resources and Environmental Sciences,China Agricultural University [2]State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau,Northwest A&F University [3]Agriculture Bureau of Binzhou [4]College of Environmental Science and Engineering,Zhongkai University of Agriculture and Engineering [5]College of Ecology and Environmental Science,Inner Mongolia Agricultural University

出　　处：《Pedosphere》2014年第1期76-83,共8页土壤圈（英文版）

基　　金：Supported by the National Basic Research Program(973 Program)of China(No.2009CB118606);the Special Fund for Agro-Scientific Research in the Public Interest of China(No.201103003);the National Natural Science Foundation of China(No.30821003)

摘　　要：The concept of critical N concentration(N_c)has been widely used in agronomy as the basis for diagnosis of crop N status,and allows discrimination between field situations of sub-optimal and supra-optimal N supply.A critical N dilution curve of N_c=34.0W^(-0.37),where W is the aboveground biomass(Mg DM ha^(-1))and N_c the critical N concentration in aboveground dry matter(g kg^(-1)DM),was developed for spring maize in Europe.Our objectives were to validate whether this European critical N dilution curve was appropriate for summer maize production in the North China Plain(NCP)and to develop a critical N dilution curve especially for summer maize production in this region.In total 231 data points from 16 experiments were used to test the European critical N dilution curve.These observations showed that the European critical N dilution curve was unsuitable for summer maize in the NCP,especially at the early growth stage.From the data obtained,a critical N dilution curve for summer maize in the NCP was described by the equation of N_c=27.2W^(-0,27),when aboveground biomass was between 0.64 and 11.17 Mg DM ha^(-1).Based on this curve,more than 90%of the data for the N deficiency supply treatments had an N nutrition index(NNI)<1 and 92%of the data for the N excess supply treatments had an NNI>1.The concept of critical N concentration （Nc） has been widely used in agronomy as the basis for diagnosis of crop N status, and allows discrimination between field situations of sub-optimal and supra-optimal N supply. A critical N dilution curve of Nc= 34.0W-0.37, where W is the aboveground biomass （Mg DM ha-1） and Nc the critical N concentration in aboveground dry matter （g kg-1 DM）, was developed for spring maize in Europe. Our objectives were to validate whether this European critical N dilution curve was appropriate for summer maize production in the North China Plain （NCP） and to develop a critical N dilution curve especially for summer maize production in this region. In total 231 data points from 16 experiments were used to test the European critical N dilution curve. These observations showed that the European critical N dilution curve was unsuitable for summer maize in the NCP, especially at the early growth stage. From the data obtained, a critical N dilution curve for summer maize in the NCP was described by the equation of Nc = 27.2W-0.27, when aboveground biomass was between 0.64 and 11.17 Mg DM ha-1. Based on this curve, more than 90% of the data for the N deficiency supply treatments had an N nutrition index （NNI） 〈 1 and 92% of the data for the N excess supply treatments had an NNI 〉 1.

关 键 词：critical N dilution curve N nutrition index optimal N management plant-based N diagnostic indicator 

分 类 号：S513[农业科学—作物学]