Climate Change Mitigation - Climate Resilient Agriculture for Ensuring Food Security - page 302

abundant, more economic feed is available, while
in production systems where the use of low qual-
ity feeds is common, high collection costs and/or
opportunity costs (manure as fertilizer or fuel)
are prohibiting the use of manure as feed.
In addition, biogas produced from the anaero-
bic digestion of animal manure, green crops, and
other forms of organic waste can be used for heat
and power generation as well as for transport
fuels - after scrubbing to remove CO 2 and H 2 S
(IEA 2008 ). Several research programs exist,
which aim at diffusing information and best prac-
tices for manure management.
According to the IEA ( 2008 ), the use of resi-
dues and waste as biomass can reduce farmers'
costs and provide them with additional income.
Based on IPCC ( 2007c ), an appropriate mix of
rice cultivation with livestock, known as inte-
grated annual crop-animal systems and tradition-
ally found in West Africa, India, Indonesia, and
Vietnam, can enhance net income, improve culti-
vated agroecosystems, and enhance human well-
being. Such combinations of livestock and
cropping, especially for rice, can improve income
generation, even in semiarid and arid areas of the
world. Furthermore, a greater demand for farm-
yard manure can create income for the animal
husbandry sector where usually poorer popula-
tion deals with. There are other benefi ts from
managing manure properly. Properly managed
feedlots, manure stacks, and manure spreading
can minimize nutrients entering surface waters
and impacts downstream. Nutrient-rich waters
promote excessive algae and aquatic plant growth
which reduces wildlife habitat and recreational
activities and may increase water treatment costs.
In addition, bacteria and other pathogens may
enter surface waters with runoff causing other
human health concerns. With proper manage-
ment, these adverse environmental impacts can
be minimized.
The effect on the environment of the manure
produced in a particular agricultural system
should be assessed by considering its role in the
total nutrient management of the system. If the
import and export of nutrients in the system is in
balance and animal manure is to play a positive
role, it implies that losses from animal manure

must be minimal. It also implies that effi cient use
is made of the manure in crop production, i.e., a
large fraction of the nutrients from the manure is
taken up by the crop. Another example is with the
aerobic treatment, which can control dangerous
bacteria such as Cryptosporidium and Salmonella ,
and they cannot exist in the presence of oxygen.
On the downside, aerobic treatment can cause
excessive loss of nitrogen as nitrogen gas, nitrous
oxide, or even ammonia if excessive aeration
rates are used. This loss of nitrogen to the atmo-
sphere can create concerns of acid rain in some
instances. Another concern is the potential loss of
the economic value as nitrogen fertilizer.
Land application of raw or composted manure
can be tailored to reduce the emission of GHGs
and their impact on the environment. Application
of more nitrogen than a crop needs via manure
will result in excess nitrogen accumulation in soil
and will increase the release of nitrogen as nitrous
oxide. Application of manure at the wrong time
of year, for example, in the very early spring, will
also increase the release of nitrous oxide, as will
applying raw manure during wet conditions.
Researchers believe that timing manure applica-
tion correctly and ensuring proper application
amounts will contribute to an overall reduction in
GHG emissions from agricultural operations.
The US EPA ( 2006 ) forecast that combined
methane emissions from enteric fermentation and
manure management will increase by 21 %
between 2005 and 2020, taking into account that
the global livestock-related methane production
is expected to increase by 60 % up to 2030.

13.1.6.9 Covering Manure Storage
Facilities
By covering manure with materials of a certain
thickness (such as plastic sheeting, organic mat-
ter, and expanded clay), the manure's surface in
contact with air is altered. This method can
reduce the emission of GHGs and store nutrients
in the manure.
Generally, covers are classifi ed as imperme-
able or permeable. Impermeable covers do not
allow gases coming from the manure to be emit-
ted to the atmosphere. Permeable covers permit
the transmission of some gases. Permeable covers