Nitrogen and Phosphorus Mineralization
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 NH4+ and NO3 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 NaHCO3, 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掳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 鈥渋ncubated鈥
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 鈥渋ncubated鈥
Repeat procedure N procedure from above.
Created: 02/02/11