Estimates of Potentially Mineralizable Soil Nitrogen Based on Short-term Incubations

Stanford, George and Carter, J.N. and Smith, S.J. (1974) Estimates of Potentially Mineralizable Soil Nitrogen Based on Short-term Incubations. Soil Science Society of America Proceedings. 38(1):99-102.

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Abstract

Nitrogen mineralization potentials were determined for a
large number of soils by a method involving determination of
N mineralized after several consecutive incubations at 35C
under optimum soil water conditions. The determination of N
mineralization potential, No, based on the first-order equation,
log (No — Nt) = log No — kt/2.303, is laborious and usually
requires incubation periods of 8 weeks or more. From the
present study, involving soils from major agricultural areas
throughout the United States, it was demonstrated that No
could be estimated reliably from the amounts of N mineralized
during 2-week incubations following preliminary incubations of
1 to 2 weeks. From the above first-order equation, No = Nt /
(1-10–kt/2.303). Hence, for a 2-week incubation (t = 2), No =
9.77Nt (Nt = N mineralized in 2 weeks and k is the rate constant,
weeks-1). Estimates of No from short-term incubations
were similar to those derived after extensive periods of incubation.
Preincubation of soils is required in order to decompose
plant residues and for other possible reasons noted. Estimates
of No from preliminary incubations are meaningless. The implications
of No as a basis for predicting amounts of soil N mineralized
under fluctuating temperature and soil water conditions
are discussed.

Item Type:	Article
NWISRL Publication Number:	0293
Subjects:	Soil > Chemistry > Nitrogen Research methodology Mass Import - autoclassified (may be erroneous)
Depositing User:	Dan Stieneke
Date Deposited:	20 Nov 2010 21:51
Last Modified:	15 Feb 2017 23:17
Item ID:	264
URI:	https://eprints.nwisrl.ars.usda.gov/id/eprint/264