Spectroscopy can be a useful tool in measuring the amount of
potassium in soil. It is fast, inexpensive, non-destructive and
measurements can be taken in situ. Potassium has a distinctive
spectral absorbance feature in a reflectance scan between 2450 and
2470nm. The depth and breadth of this feature can indicate the
relative amount of potassium contained in the soil sample.
Potassium is a key ingredient in plant health, responsible for the
movement of water, nutrients, and carbohydrates in plant tissues.
Potassium is involved with enzyme activation within plants which
affects protein, starch and adenosine triphosphate (ATP) production.
The production of (ATP) can regulate photosynthesis rates.
Potassium also helps to regulate the opening and closing of the
stomata which regulates the exchange of water vapor, oxygen, and
carbon dioxide. If K is deficient or not supplied in adequate amounts,
growth is stunted and yield is reduced. Potassium is also key in
fighting biotic (pathogens, insects, weeds) and abiotic (drought,
salinity, cold, frost, and waterlogging) stresses.
The PSR+ is a lightweight, reliable high resolution NIR
spectroradiometer designed for field use. The PSR+ covers the full
UV/VIS/NIR range from 350-2500 nanometers with unmatched
sensitivity and accuracy. It is easy for one person in the field to use
with an optional handheld microcomputer and direct screw-on
lenses, or fiberoptic connection to a pistol grip or sample contact
probe. The PSR+ includes our exclusive DARWin SP Data Acquisition
software with access to the USGS spectral library and 19 vegetation
indices. It can work in standalone mode to store up to 1000 field
scans before offloading. It is supplied with two rechargeable lithium-
ion batteries each capable of up to 4 hours of use for a total of 8
hours of scanning. The PSR+ is also available with a benchtop probe
and sample compactor for soil analysis use in the lab.
Optional EZ-ID sample identification software includes access to
mineral identification libraries — very useful for identifying clays in
soil. Using pattern matching algorithms, EZ-ID matches your target
scan to known samples and provides a matching “confidence level”
percentage. It also allows you to quickly take scans of known
samples and create your own region-specific soils library.
Since DARWin software saves all your spectra as ASCII files, it can
easily be imported into 3rd party analysis or chemometric programs
like TSG, Camo’s Unscrambler and R2.
In addition to measuring potassium content, other soil analysis
applications can include: nitrogen and phosphorus measurement,
topsoil fertility, erosion risk, hydraulic properties, soil degradation,
total organic carbon, organic matter in soil, CEC, and indirect
measurement of soil pH.
Every Spectral Evolution instrument includes
DARWin SP Data Acquisition software.
Scans can be compared using multiple
scans in a single plot.
Measuring potassium in soil
1 Canal Street ◊ Unit B1
Lawrence, MA 01840 USA
Tel: 978 687-1833 ◊ Fax: 978 945-0372
Copyright © 2012 Spectral Evolution, Inc
The benchtop probe includes a sample compactor for powders and soils. Soil analysis can also be done in
the field with our 10mm or 3mm spot size contact probes.
PSR+ works with our benchtop probe and compactor for in the lab soil analysis.