Procedure
Initial Nitrogen (Day 0)
In a 50 ml centrifuge tube
- 10 g Field fresh soil
- 20 ml 1 M KCl (74.59 g KCl/liter)
Place on orbital shaker for one (1) hour.
Centrifuge and decant into a 15 ml centrifuge tube.
Measure NH 4 + and NO 3 using colorimetric methods within a week.
Initial Phosphorus (Day 0)
In a 50 ml centrifuge tube (if available, Oakridge tubes)
- 10 g Field fresh soil
- 1 Bicarb charged AEM resin strip (Charging: shake strips 10 minutes in 100 ml 0.5 M NaHCO 3 , rinse 3 times with DI water, shake dry)
- 20 ml DI water
Shake for 4 hours, centrifuge, and discard supernatant
In a 250 ml flask
- 1 AEM strip
- Extract resin with 25 ml of 0.5 M HCl (41.7 ml 12M HCl/liter) for 18 hour on a shaker.
Measure Resin P using the ascorbic acid colorimetric method within a day.
Incubated N and P (Day 14)
In a 125 ml sample cup
- 20 g Field fresh soil
Loosely put on the lid.
Place in the incubator at 25°C for around two (2) weeks.
Check moisture every week. If dry, then spray once with distilled water.
In 14 days (two weeks)
In a 50 ml centrifuge tube (if available, Oakridge tubes)
- 10 g Soil for P analysis from the incubated soil
- Label “incubated”
Repeat procedure P procedure from above.
In the incubated 125 ml sample cup
- 10 g Remaining soil for N analysis
- 20 ml 1 M KCl
- Label “incubated”
Repeat procedure N procedure from above.
Created: 02/02/11