Agriculture Reference
In-Depth Information
the mixture. The later rise in nitrate ion concentration was attributed to the action of
ammonium- and nitrite-oxidizing bacteria.
The two-step composting procedure pioneered by Saha et al. (
2012
) yielded
promising results in terms of nitrogen retention. As noted earlier, these researchers
first treated the lignocellulosic component with white rot fungus, which is capable
of breaking down the lignin portion. Then, in a second step, the pretreated lignocel-
lulosic component was combined with poultry droppings. Losses of nitrogen were
lower than in the case of conventional processing, in which all components are
combined at the beginning of the process.
3.5.3
Soil Fertility and Plant Growth
The ultimate test of compost, in many cases, is whether it will support vibrant plant
growth. Only a few recent articles have included fertility tests as part of their analy-
sis (Wang et al.
2011
; Thomas et al.
2013
). Rather, the recent studies have more
often considered other factors that are expected to be beneficial for plants. For in-
stance, Saha et al. (
2012
) used ion exchange capacity and humic substance con-
tent of the compost as measures of quality. Alternatively, some studies have been
concerned with the suitability of the compost as a medium for the growth of edible
mushrooms (Farnet et al.
2013
).
3.5.4
Restoration of Soil under Challenging Circumstances
As reported by Bonoli and Dall'Ara (
2012
), composting can be considered as a
contributing strategy for restoration of soil in difficult sites. The cited work provides
an example of what can happen when organic matter is employed in such efforts in
the absence of composting. Sludge obtained from paper mill operations was applied
to cover an area that previously had been used as a quarry. It became evident that
decomposition of the sludge under anaerobic conditions was giving rise to sub-
stantial amounts of biogases, which were being released to the atmosphere. The
immediate problem was solved by constructing “chimneys” to direct such gases to
a centralized area, where the gases were required to pass through a 1 m thick “hat”
of compost material. Presumably, biochemical interactions within the compost were
able to consume much of the problematic gases.
Iwai et al. (
2013
) described a case in which a compost mixture was evaluated for
restoring of barren coastal ground in contact with seawater. Due to the contamina-
tion of the site with iron, the strong chelating ability of composts was regarded as a
positive attribute. Factors contributing to solubility of compost components in the
salt water were studied.
