Research Article

Temporal Variation of N Isotopic Composition of Decomposing Legume Roots and Its Implications to N Cycling Estimates in Tracer Studies in Agroforestry Systems

Table 1

Parameters of the residue decomposition model for the residue application (RA) and full interaction (FI) experiments. Where 15N is not given, it is defined by 15N of the source pool.

ParameterInitial valueSource
CodeRAFI UnitRAFI

Residuea
 N contentNR971332mg pot−1This study[6]
 C : NR14.530.2This study[6]
15N 15NR180318This study[6]
Microbial biomass
 N contentNB00mg pot−1This study[6]
 C : NRB RB = 16.1 − 123/R,
RB = 7.8 when R < 14.8
[24]
Newly formed humified organic matter
 N contentNH00mg pot−1This study[6]
 C : N RH10.5[33]
Inorganic N from residue
 N contentNSR00mg pot−1This study[6]
Soil native inorganic N
 N contentNSN2117mg kg−1This study[6]
15N 15NSN4.37.2This study[6]
Plant biomass
 N contentbNP5268mg pot−1This study[6]
 Shoot 15N 15NS4.319.8This study[6]
 Total N uptake rate 3.23.0mg d−1This study, est.[6]

Corresponding to fine roots and nodules for RA, and all roots and nodules for FI.
bIncluding shoot and root N.