A simple chemical method of assessing potentially available organic nitrogen in soil

Abstract

A simple chemical method of assessing potentially available organic N in soil is described. It involves determination of the ammonium‐N produced by treatment of the soil sample with 2M KCl at 100°C for 4 hours in a block digester. The method is rapid and precise, and its results are not significantly affected by air‐drying or air‐dry storage of the soil sample before analysis. It is well suited for routine use in soil testing laboratories because it does not require filtration or transfer steps. Studies using 33 Brazilian soils showed that the results obtained by this method were highly correlated with those obtained by aerobic and anaerobic incubation methods of assessing potentially available organic N in soil.

Key words:

• Block digester
• aerobic incubation method
• anaerobic incubation method
• air‐drying
• air‐dry storage

Notes

Journal Paper No. J‐11973 of the Iowa Agric, and Home Econ. Exp. Stn., Ames, Iowa. Projects 2655 and 2672.