Climate Change Mitigation - Climate Resilient Agriculture for Ensuring Food Security - page 316

in theory. If this is so, it would remarkably reduce
production costs and achieve considerable eco-
nomic benefi ts because no more extra expense
would be required to maintain long-term CH 4
mitigation.

(i) Advantages
• Saving grain and reducing the depen-
dence of animal husbandry on grain.
• Improving palatability and the feed intake
of forage by livestock.
• Increasing the digestibility of organic mat-
ters in forage by 10-12 % and doubling
the content of crude protein.
• The materials are easily accessed with
simple methods.
• Reducing feeding costs and increasing
economic benefi ts.
(ii) Disadvantage
•

13.2.3 Straw Ammonization
and Silage

13.2.3.1 Straw Ammonization
Straw ammonization is a process by which low-
value forage such as cornstalks, rice straw, wheat
straw, and straw of other crops is ammoniated.
Adding liquid ammonia, urea, or ammonium
bicarbonate as ammonia sources result in the
straw lignin being completely degraded, while
the nutrients are enhanced. It is made more easily
digestible by rumen microorganisms, which
increases the digestibility of forage (Fig. 13.15 ).
The cellulose part of the straw can be digested
and utilized by ruminant animals, while the lignin
part cannot be digested. The main function of
ammonization is to generate ammonolysis reac-
tion using ammonia and straw, by damaging the
ester bonds between lignin and polysaccharide,
so that it can contact with digestive enzymes
more easily, with an improvement in digestibility
of straw. The digestibility and feed intake of
ammoniated straw can be increased by approxi-
mately 20 %, and the content of crude protein in
ammoniated straw can be increased by two to
three times (Guo 1996 ).

The ammonia utilization effi ciency is as
low as approximately 50 %. The surplus
ammonia is discharged into the environ-
ment after the ammonization facilities are
opened, which causes environmental pol-
lution and threatens the health of animals
and human beings.

13.2.3.2 Straw Silage
Straw silage refers to forage that is prepared
through the fermentation of chopped fresh green
fodder, forage grass, and all kinds of vines and
other materials by lactobacillus in the anaerobic
conditions of an airproof silage container (tower
or silo).
To make straw silage, fresh plants are tightly
packed in the airtight container, and the sugar
contained in the raw materials is converted into
organic acids (mainly lactic acid) via the anaer-
obic fermentation of microorganisms (mainly

Fig. 13.15 Process of
straw ammonization
(Source: hbav.gov.cn)