What is it about?
The experiment comprised of three irrigation scheduling treatments based on IW/CPE ration of 0.6, 0.8 and 1.2 and three nitrogen level treatments, i.e., 100, 200 and 300 kg of N ha-1, respectively, with three replications in a split plot design. The spectral reflectance was measured before irrigation at tasseling and dough stage of the maize crop using portable field spectroradiometer. The results of stepwise multiple linear regression indicated the highest predicting capability of spectral bands 540 nm, 780 nm and 860 nm for leaf nitrogen and 700 nm, 740 nm and 860 nm for leaf water content. The derived biophysical parameters based on spectral reflectance viz. relative leaf water content (%), leaf area index and leaf nitrogen contentment (%) at tasseling stage of maize crop accounted for 80%, 61% and 66% variation in grain yield, respectively.
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Why is it important?
Realization of agricultural crop condition through field survey is quite expensive, time consuming and sometimes not practical for remote locations. Optical remote sensing techniques can provide information on real condition of the crops by observing spectral reflectance at different crop growth phases and is less expensive and less time consuming. Hyperspectral remote sensing provides a unique opportunity for non-destructive, timely and accurate estimation of crop biophysical and biochemical properties. In this study, a field experiment was conducted to identify the water and nitrogen stress indicative spectral bands using ground-based hyperspectral data and to assess the predictive capability of selective bands on yield of maize under water and nitrogen stress environment.
Perspectives
The potential for hyper-spectral remote sensing to detect water and nitrogen stress in irrigated maize was illustrated this investigation. Multiple linear regression analysis was performed using backward elimination stepwise method, and best combinations of bands were selected based on highest coefficient of determination for biophysical parameters viz. Leaf nitrogen (%), relative leaf water content and leaf area index. The sensitiveness of spectral reflectance pattern at different wavelengths as influenced by water and nitrogen stress was illustrated. The sensitivity of spectral reflectance to age of the crop was established.
BALAJI NAIK BANOTH
Professor Jayashankar Telangana State Agricultural University
Read the Original
This page is a summary of: Hyperspectral Remote Sensing for Determining Water and Nitrogen Stress in Maize during Rabi Season, Current Journal of Applied Science and Technology, January 2020, Sciencedomain International,
DOI: 10.9734/cjast/2019/v38i630456.
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