Remote estimation of nitrogen and chlorophyll contents in maize at leaf and canopy levels

• Published in: International journal of applied earth observation and geoinformation Vol. 25; pp. 47 - 54
• Main Authors: Schlemmer, M., Gitelson, A., Schepers, J., Ferguson, R., Peng, Y., Shanahan, J., Rundquist, D.
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier B.V 01.12.2013; Elsevier
• Subjects: Applied geophysics; Chlorophyll; Earth sciences; Earth, ocean, space; Exact sciences and technology; Internal geophysics; Nitrogen; Reflectance; Remote sensing; Vegetation index; NDV; Chlorophyll; Vegetation index; Chl; CI; EVI; MTCI; Nitrogen; N; Remote sensing; Reflectance; irrigation; leaves; reflectance; nitrogen; Space remote sensing; near infrared radiation; chlorophyll; satellite measurements; vegetation; cultivated soils
• ISSN: 1569-8432; 1872-826X
• DOI: 10.1016/j.jag.2013.04.003

•Leaf nitrogen and chlorophyll content were retrieved accurately from leaf reflectance spectra.•Canopy nitrogen and chlorophyll content were closely related.•Vegetation indices using green and red-edge spectral bands were used for accurate chlorophyll and nitrogen estimation at canopy level.•Optimal spectral bands found for nitrogen and chlorophyll estimation match well-spectral bands of near future space systems. Leaf and canopy nitrogen (N) status relates strongly to leaf and canopy chlorophyll (Chl) content. Remote sensing is a tool that has the potential to assess N content at leaf, plant, field, regional and global scales. In this study, remote sensing techniques were applied to estimate N and Chl contents of irrigated maize (Zea mays L.) fertilized at five N rates. Leaf N and Chl contents were determined using the red-edge chlorophyll index with R2 of 0.74 and 0.94, respectively. Results showed that at the canopy level, Chl and N contents can be accurately retrieved using green and red-edge Chl indices using near infrared (780–800nm) and either green (540–560nm) or red-edge (730–750nm) spectral bands. Spectral bands that were found optimal for Chl and N estimations coincide well with the red-edge band of the MSI sensor onboard the near future Sentinel-2 satellite. The coefficient of determination for the relationships between the red-edge chlorophyll index, simulated in Sentinel-2 bands, and Chl and N content was 0.90 and 0.87, respectively.