Molecular properties of a fermented manure preparation used as field spray in biodynamic agriculture
R. Spaccini & P. Mazzei & A. Squartini & M. Giannattasio & A. Piccolo
Abstract Manure products fermented underground in
cow horns and commonly used as field spray (preparation
500) in the biodynamic farming system, were characterized
for molecular composition by solid-state
nuclear magnetic resonance [13C cross-polarization
magic-angle-spinning NMR (13C-CPMAS-NMR)] spectroscopy
and offline tetramethylammonium hydroxide
thermochemolysis gas chromatography-mass spectrometry.
Both thermochemolysis and NMR spectroscopy
revealed a complex molecular structure, with lignin
aromatic derivatives, polysaccharides, and alkyl compounds
as the predominant components. CPMAS-NMR
spectra of biodynamic preparations showed a carbon
distribution with an overall low hydrophobic character
and significant contribution of lignocellulosic derivatives.
The results of thermochemolysis confirmed the
characteristic highlighted by NMR spectroscopy, revealing
a molecular composition based on alkyl components
of plant and microbial origin and the stable incorporation
of lignin derivatives. The presence of biolabile
components and of undecomposed lignin compounds in
the preparation 500 should be accounted to its particularly
slow maturation process, as compared to common
composting procedures. Our results provide, for the first
time, a scientific characterization of an essential product
in biodynamic agriculture, and show that biodynamic
products appear to be enriched of biolabile components
and, therefore, potentially conducive to plant growth
stimulation.
Keywords Biodynamic . Thermochemolysis . 13C-CPMAS
NMR . Lignin