Estimating Plant Nitrogen Concentration of Maize Using a Leaf Fluorescence Sensor across Growth Stages

Remote Sensing

Haigang Li¹  Xinbing Wang²  Rui Dong²  Weina Zhang²  Yuxin Miao²  Fei Yuan³  Zhichao Chen⁴ 

[1] College of Grassland, Resources and Environment, Inner Mongolia Agricultural University, Hohhot 010011, Inner Mongolia, China;College of Resources and Environment Sciences, China Agricultural University, Beijing 100193, China;Department of Geography, Minnesota State University, Mankato, MN 56001, USA;School of Surveying and Land Information Engineering, Henan Polytechnic University, Jiaozuo 454000, China;

关键词: nitrogen status diagnosis;    Dualex sensor;    precision nitrogen management;    leaf position;    proximal sensing;    nitrogen balance index;   

DOI  :  10.3390/rs12071139

来源: DOAJ

【 摘 要 】

Nitrogen (N) is one of the most essential nutrients that can significantly affect crop grain yield and quality. The implementation of proximal and remote sensing technologies in precision agriculture has provided new opportunities for non-destructive and real-time diagnosis of crop N status and precision N management. Notably, leaf fluorescence sensors have shown high potential in the accurate estimation of plant N status. However, most studies using leaf fluorescence sensors have mainly focused on the estimation of leaf N concentration (LNC) rather than plant N concentration (PNC). The objectives of this study were to (1) determine the relationship of maize (Zea mays L.) LNC and PNC, (2) evaluate the main factors influencing the variations of leaf fluorescence sensor parameters, and (3) establish a general model to estimate PNC directly across growth stages. A leaf fluorescence sensor, Dualex 4, was used to test maize leaves with three different positions across four growth stages in two fields with different soil types, planting densities, and N application rates in Northeast China in 2016 and 2017. The results indicated that the total leaf N concentration (TLNC) and PNC had a strong correlation (R² = 0.91 to 0.98) with the single leaf N concentration (SLNC). The TLNC and PNC were affected by maize growth stage and N application rate but not the soil type. When used in combination with the days after sowing (DAS) parameter, modified Dualex 4 indices showed strong relationships with TLNC and PNC across growth stages. Both modified chlorophyll concentration (mChl) and modified N balance index (mNBI) were reliable predictors of PNC. Good results could be achieved by using information obtained only from the newly fully expanded leaves before the tasseling stage (VT) and the leaves above panicle at the VT stage to estimate PNC. It is concluded that when used together with DAS, the leaf fluorescence sensor (Dualex 4) can be used to reliably estimate maize PNC across growth stages.

【 授权许可】

Unknown