Determining Wavelenth for Nitrogen and Phosphorus Nutrients Through Hyperspectral Remote Sensing in Wheat (Triticum aestivum L.) Plant

Abstract

For precision management of nitrogen (N) and phosphorus (P) nutrients, soil or plant test techniques are either expensive or time taking. Hyperspectral remote sensing plays an important role for minimizing loss and judicious use of supply nutrient in timely fashion. To determine wavelength from hyperspectral data for N and P nutrient, glasshouse experiments were conducted at Dookie, Australia in year 2006 and 2007 on wheat (Triticum aestivum L. cv. Ruby) with nutrients (Control, 10% N, zero N, 10% P and Zero P) and harvest dates (2 leaf, Z12; Initiation of Tillering, Z20; Stem Elongation, Z30; booting, Z40 and grain filling, Z70). Results showed that the control N and P plants can be separated from stressed plant at all investigated growth stages and in a specific wavelength range. Control N and stressed plants are found significantly separable at 212–385 nm and 440–443 nm at Z12, while at Z20, separable in blue, green, red, red edge and NIR; at Z30, separable at 244–521.5 nm and 591–1100 nm and at Z40, separable at 350–415 nm and 706–934.5 nm; at Z70, separable at 355–515.5 nm, 617–695 nm and 726–1075 nm. Likewise, results showed that control P and stressed plant were found significantly separable at 245.5–504 nm and 549–1100 nm at Z12, while at Z20, separable at entire wavelength ranges except at 490–512 nm, 638–69 nm and 732–762 nm. At Z30, significantly separable P stressed were found  at 227.5–230 nm and 364–367 nm; at Z40, 544.5–612.5 nm and 687–761.5 nm and at Z70, 355–521 nm, 644–692 nm and 716–929.5 nm. The shifting of the wavelength among the different plant growth stages was also found.