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

• Published in: Pedosphere Vol. 24; no. 1; pp. 76 - 83
• Main Authors: YUE, Shan-Chao, SUN, Fu-Lai, MENG, Qing-Feng, ZHAO, Rong-Fang, LI, Fei, CHEN, Xin-Ping, ZHANG, Fu-Suo, CUI, Zhen-Ling
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.02.2014; College of Resources and Environmental Sciences, China Agricultural University, Beijing 100193 China; College of Ecology and Environmental Science, Inner Mongolia Agricultural University, Hohhot 010019 China; College of Environmental Science and Engineering, Zhongkai University of Agriculture and Engineering, Guangzhou 510225 China%College of Resources and Environmental Sciences, China Agricultural University, Beijing 100193 China; State Key Laboratory of Soil Erosion and Dryland Farming on the Loess Plateau, Northwest A&F University, Yangling 712100 China%Agriculture Bureau of Binzhou, Binzhou 256600 China%College of Resources and Environmental Sciences, China Agricultural University, Beijing 100193 China%College of Resources and Environmental Sciences, China Agricultural University, Beijing 100193 China
• Subjects: critical N dilution curve; N nutrition index; optimal N management; plant-based N diagnostic indicator; Zea mays; 中国北方; 临界; 地上生物量; 夏玉米生产; 平原; 曲线; 氮素营养诊断; 验证; optimal N management; N nutrition index; critical N dilution curve; plant-based N diagnostic indicator
• ISSN: 1002-0160; 2210-5107
• DOI: 10.1016/S1002-0160(13)60082-X

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.