A FUNCTION DESCRIBING NITROGEN AVAILABILITY FROM ORGANIC SOURCES

D. Crohn
A simple first-order mathematical function is presented to describe net nitrogen (N) immobilization and mineralization from organic materials spread on or incorporated into horticultural soils. To facilitate the representation of immobilization, kinetics are determined by a conveniently measured carbon dioxide (CO2-C) evolution rate. Other parameters include a substrate conversion efficiency, the C:N ratio of microbial decomposers, and the initial C and N contents of the materials. The model was parameterized using a previously reported incuba-tion study of uncomposted lawn trimming materials (Sullivan et al., 2004). To avoid overfitting, parameters are lumped between the different treatments whenever reasonable. All parameters were lumped except for two labile/recalcitrant partition factors, one for C and one for N. Results for each of eight lawn trimming materials represented evolving C very well (r2=0.99). Nitrogen immobilization and release fits were reasonable (r2
Crohn, D. (2014). A FUNCTION DESCRIBING NITROGEN AVAILABILITY FROM ORGANIC SOURCES. Acta Hortic. 1018, 295-305
DOI: 10.17660/ActaHortic.2014.1018.31
https://doi.org/10.17660/ActaHortic.2014.1018.31
model, mineralization, immobilization, prediction, decomposition, lawn trimmings
English

Acta Horticulturae