PRS Technology
To ensure consistent performance, PRS® Probes are regenerated prior to each use by consistently saturating the ion-exchange membranes with the same counter-ions.
PRS® Probes are first soaked (with agitation) in 0.5 M HCl to saturate exchange sites with H+ or Cl-, then repeatedly soaked in NaHCO3 to saturate exchange sites with Na+ or HCO3-. Each soaking replaces approximately 95% of the ions on the membrane with ions from the soaking solution. As a final step, anion PRS® Probes are soaked in a solution of 0.01 M EDTA to increase adsorption of P and micronutrients.
Each batch of regenerated probes is tested prior to use by analysis of three subsamples consisting of two probes. The objective is for regenerated PRS® Probes to have negligible levels relative to those obtained after soil burial. Potential issues should be discussed with an R&D coordinator.
|
|
Regenerated PRS® Probes, 2010 to 2012 (n>150) |
Typical soil |
|
Ion |
(mean ± st. dev.) |
(range) |
|
|
ug per 10 cm2 |
|
|
NO3-N |
2 ± 1 |
5 to 1000 |
|
NH4-N |
0.3 ± 0.4 |
2 to 10 |
|
P |
0.3 ± 0.3 |
0.2 to 10 |
|
K |
4 ± 3 |
20 to 200 |
|
S |
4 ± 3 |
10 to 200 |
|
Ca |
30 ± 20 |
400 to 3000 |
|
Mg |
4 ± 4 |
80 to 500 |
|
Fe |
1 ± 1 |
1 to 10 |
|
Mn |
0.1 ± 0.2 |
0.5 to 20 |
|
Cu |
0.04 ± 0.12 |
0.02 to 0.2 |
|
Zn |
0.1 ± 0.1 |
0.2 to 2 |
|
B |
1 ± 1 |
0 to 3 |
|
Al |
19 ± 9 |
10 to 50 |