Estimating plant lignin content

Using a field spectroradiometer such as the Spectral Evolution PSR+, a researcher can get an estimate of lignin content in the field or in a lab. Lignin is a polymer of phenylpropanoid and accounts for 10 to 35% of dry weight of plants and acts as a barrier to decomposition of cellulose and hemicellulose. NIR spectroscopy provides a useful tool for lignin measurement with key absorption features at 1380, 1404, 1646, 1672, 1702, 1725, 1898, 1927, 1996, 2100, 2280 and 2322nm. All spectra taken by the PSR+ are stored as ASCII files for use with other third party software that includes R, ENVI, and various chemometrics software programs.

The PSR+ is a full range, UV-VIS-NIR instruments with high resolution and low noise. DARWin SP Data Acquisition software is included with every instrument. The PSR+ provides the field researcher with the option of using direct attach lenses for standoff measurements or a fiberoptic cable with FOV lenses, a contact probe, sphere, pistol grip, our unique leaf clip and other accessories. The PSR+ offers auto-exposure, auto-dark correction, and auto-shutter for one touch operation.

By measuring lignin, process decisions can be made before pulping, biomass can be characterized for use as fuel, and different species with lower lignin content can be planted for forage.

The PSR+ is lightweight and rugged—built with photodiode arrays and no moving parts for consistent reliable operation in field conditions. Additional vegetation remote sensing applications include:

  • Species identification
  • Assessment of phosphorous and potassium nutrients in plants
  • Measurement of moisture and water content
  • Soil characterization and analysis
  • Ground truthing satellite imagery and measurements
  • Total organic carbon (TOC) in soil
  • Biomass research