Abstract:
Organic sources are vital for
crop nutrient management, but nutrient
release from organic manure depends on
temperature and other factors. We conducted
a laboratory incubation study to investigate
how temperature (15, 25, 35°C) affects the
decomposition of common organic manure,
which has not yet been explored in
Bangladesh. The organic manures used in this
study are poultry manure (PM),
vermicompost (VC), bio-slurry (BS), cow
dung (CD), water hyacinth compost (WHC)
and rice straw compost (RSC), which were
compared with a control treatment (only soil).
Carbon mineralisation and CO2 emission
from microbial respiration varied among
organic manures and temperature regimes.
The RSC- and WHC-treated soils had a
higher C mineralisation than the other
manures at 35°C. The mineralisation of C
among the organic manures followed the
order: RSC > WHC > CD > VC > BS > PM
> control. Among the temperature regimes, C
mineralisation followed the order 35°C >
25°C > 15°C. Manure mineralisation was
associated with mineralisable C pools (carbon
availability factor, Caf), and 16.4–36.5%
organic C was released. Irrespective of
temperature regimes, the highest easily
mineralisable Caf was recorded in PMamended
soil, followed by VC-amended soil.
RSC had the lowest Caf under all temperature regimes. The Caf values of all incubated
manures were higher under a 35°C
temperature regime. Compost preparation
from organic manure and its utilisation as an
integrated nutrient management component
can play essential roles in mitigating climate
change, reducing environmental degradation,
and building more sustainable and resilient
agrifood systems.
