Agriculture Reference
In-Depth Information
3.4.4
Analysis of Chemical Transformations
Significant progress has been reported recently in various aspects of chemical anal-
ysis related to composting. Methods employed have included
13
C NMR spectros-
copy (Caricasole et al.
2011
), X-ray diffraction (Hu et al.
2011
; Razali et al.
2012
),
pyrolysis followed by gas chromatography and mass spectroscopy (Iwai et al.
2013
), denaturing gradient gel electrophoresis (Lü et al.
2012
; Li et al.
2013
), DNA
sequence detection (Xiao et al.
2011
; Wei et al.
2012
), and two-dimensional Fourier
transform infrared spectroscopy with fluorescent labeling of specific components
in compost (Wang et al.
2012a
). He et al. (
2013
) employed multivariate statistical
analysis to look for correlations among different chemical changes accompanying
composting. Spectral information was considered in two groups, i.e., the progress
of decomposition and the stabilization or maturation of components in the compost.
3.5
Composting of Lignocellulosic for the Stewardship
of Soils
The word “stewardship” implies taking responsibility in a caring, active manner.
The word has special applicability in the case of composting, because natural, gen-
erally eco-friendly processes can be used to restore the fertility to soils. Several
recent studies have emphasized the importance of the lignocellulosic component
in compost mixtures relative to soil quality. Indeed, many studies have focused
on indices such as the C:N ratio to assess the degree or maturity and suitability of
composts for different kinds of applications in soil, e.g., lawn care, vs. flowers, vs.
vegetables, etc. (Hubbe et al.
2010
; Cheng et al.
2013
). According to Vidal-Beaudet
et al. (
2012
) it is not uncommon for reconditioned urban soils to contain as much as
50 % compost by volume. Consequently, it is very important that such material be
chemically stable and has suitable structure and density.
3.5.1
Lignocellulosic Materials to Provide Bulk and Aeration
in Soils
The ability of lignocellulosic materials to provide bulking and permeability to com-
posts and/or to the soils to which compost is added has been documented in recent
studies (Serramia et al.
2010
; Doublet et al.
2011
; Zhao et al.
2011a
,
b
; Luz Cayuela
et al.
2012
). Such studies have shown, for instance, that the use of “bulking agents”
can decrease the overall time needed to reach fixed levels of maturation of compost
(Doublet et al.
2011
). One needs to be careful, however, in attributing all such ef-
fects to bulking. As shown earlier, lignocellulosic materials are often essential to
achieving an optimum C:N ratio such that a compost pile is able to self-heat effec-
tively and to support a vibrant microbial community.
