Detection of nitrogen and phosphorus nutrient status in bermudagrass using spectral radiance

Nitrogen (N) and phosphorus (P) are two of the most limiting nutrients for crop production. Because of this, continued interest focuses on improving Nand P-use efficiency. Spectral radiance measurements were evaluated to identify optimum wavelengths for dual detection of N and P status in bermudagrass (Cynodon dactylon L.). A factorial arrangement of treatments (0, 112, 224, and 336 kg N ha(-1) and 0, 29, and 58 kg P ha(-1)) was applied to an established bermudagrass pasture for further study using a randomized complete block design. A wide range of spectral radiance measurements (276-831 nm) was obtained from each plot using a PSD1000 Ocean Optics fiber optic spectrometer. The resulting spectra were partitioned into 10-nm bands.