Abstract

The nitrogen (N) supply from crop residues and organic fertilisers must be integrated to N fertiliser recommendations as carefully as possible. Thus, prediction of carbon (C) and N mineralisation patterns of plant residues is important for both agronomic and environmental purposes. In this collaborative project of five Nordic countries, we tested the success of stepwise chemical digestion (SCD; Van Soest analysis), near infrared reflectance (NIR) spectroscopy and residue N concentration in the prediction of C and N mineralisation dynamics. One of the major objectives was to develop low-cost NIR analyses as an alternative method of residue quality characterisation. A total of 249 plant materials were collected and their NIR spectra were measured. According to NIR analysis, 113 plant residues of widely differing qualities were selected and analysed for total N and subjected to SCD. These three methods were used to partition plant residue C and N into litter pools in a mechanistic, dynamic decomposition model and to predict parameters in a number of empirical functions to describe net C and N mineralisation dynamics of 76 different plant materials. C mineralisation was predicted almost equally well by NIR and SCD (r2=0.91–0.93) but clearly better than by N concentration (r2=0.85). N mineralisation was better predicted by SCD fractions (r2=0.53) than by N concentration (r2=0.50) and NIR (r2=0.45). The decomposition model initialised from SCD, NIR or N concentration performed almost equally well (r2=0.69–0.76). According to these results, NIR spectra and total N concentration are cost-effective alternatives for prediction of plant residue decomposition. These methods could be used for plant residue characterisation in N recommendations

Keywords

carbon; C/N ratio; mineralisation; near infrared reflectance spectroscopy; NIR; Van Soest fractionation

Published in

Acta Horticulturae
2006, Volume: 700, pages: 57-62
Title: Acta Horticulturae 700

Conference

International Symposium Towards Ecologically Sound Fertilisation Strategies for Field Vegetable Production

SLU Authors

• Stenberg, Bo

  • Department of Soil Sciences, Swedish University of Agricultural Sciences
    

• Lundström, Christina

  • Department of Soil Sciences, Swedish University of Agricultural Sciences
    

UKÄ Subject classification

Agricultural Science
Horticulture
Environmental Sciences related to Agriculture and Land-use


Permanent link to this page (URI)

https://res.slu.se/id/publ/9198