energy and substrates and promotes the biological diversity that helps to maintain
soil quality and ecosystem functionality. Once the soil is continuously cultivated for
agricultural production, especially in the tropical regions, SOM is rapidly
decomposed due to modifications in soil physical properties such as aeration, soil
temperature, and water content and productivity of soil decline due to a decrease in
organic matter content and soil pH. This condition can affect many soil functions
that are either directly or indirectly related to SOM, due to its capacity to retain water
and nutrients. Although the breakdown rate of SOM can be faster in the tropics,
regular inputs of organic amendments can promote a build-up of SOM. Regular
additions of organic manures are considered to be an effective way to achieve soil
organic carbon (SOC) sequestration and supplying micronutrients to crops in comparison with the use of chemical fertilizers alone in a tropical agroecosystem
(Surendran et al. 2016).
10.6 Bioenergy and Biogas Management
From 1964 to 2015, global food consumption increased per person per day from
about 2358 kcal/day in the 1960s to 2940 kcal/day in 2015. It is predicted to expand
3050 kcal/day in the 2030s (Vasileska and Rechkoska 2012). The growth in food
consumption has also been accompanied by significant changes and shifts from grain
foods to more livestock and vegetable oil products (Bruinsma 2003). Livestock
products provide 17% global kilocalorie consumption and 33% of global protein
consumption (Fonseca 2009). Moreover, the population is also predicted to increase
steadily year by year. Food and Agriculture Organization (FAO) predicts the
increase in the population of 9.7 billion in 2050 (FAO 2018). It means there is an
increase in livestock and vegetable oil products consumption. In 2018, especially in
Indonesia, meat consumption increased by 12.5%, egg consumption increased by
6.64%, chicken consumption increased by 11.22% as compared to 2016 data
(Statistics Indonesia 2018). In recent years, livestock and poultry farming are
overgrowing, but it is likely to be adversely affected by climate change, competition
for land and water, and food security. The growth of livestock and poultry farming is
not accompanied by good waste management. Manure becomes one of the biggest
and most important waste in livestock and poultry farming. The impact of livestock
and poultry farming is not only on the soil and water environment but also on the
atmospheric environment. The effect on the air environment is from methane, carbon
dioxide, and nitrous oxide emissions that cause global warming. The livestock
farming contributes about 14.5% of total global emissions (Rojas-Downing et al.
2017). Further, about 27% of livestock emissions are in the form of carbon dioxide,
29% of livestock emissions as nitrous oxide, and 44% in the form of methane
(Fig. 10.3).
Tubiello et al. (2014) reported that the most significant global warming emission
comes from enteric fermentation, manure, and synthetic fertilizer (40%, 15%, and
13%, respectively). Greenhouse gases emissions from enteric fermentation consist of
methane produced in the digestive system of ruminants and to a lesser extent of
10 Tropical Biological Natural Resource Management Through Integrated. . .
223
soil quality and ecosystem functionality. Once the soil is continuously cultivated for
agricultural production, especially in the tropical regions, SOM is rapidly
decomposed due to modifications in soil physical properties such as aeration, soil
temperature, and water content and productivity of soil decline due to a decrease in
organic matter content and soil pH. This condition can affect many soil functions
that are either directly or indirectly related to SOM, due to its capacity to retain water
and nutrients. Although the breakdown rate of SOM can be faster in the tropics,
regular inputs of organic amendments can promote a build-up of SOM. Regular
additions of organic manures are considered to be an effective way to achieve soil
organic carbon (SOC) sequestration and supplying micronutrients to crops in comparison with the use of chemical fertilizers alone in a tropical agroecosystem
(Surendran et al. 2016).
10.6 Bioenergy and Biogas Management
From 1964 to 2015, global food consumption increased per person per day from
about 2358 kcal/day in the 1960s to 2940 kcal/day in 2015. It is predicted to expand
3050 kcal/day in the 2030s (Vasileska and Rechkoska 2012). The growth in food
consumption has also been accompanied by significant changes and shifts from grain
foods to more livestock and vegetable oil products (Bruinsma 2003). Livestock
products provide 17% global kilocalorie consumption and 33% of global protein
consumption (Fonseca 2009). Moreover, the population is also predicted to increase
steadily year by year. Food and Agriculture Organization (FAO) predicts the
increase in the population of 9.7 billion in 2050 (FAO 2018). It means there is an
increase in livestock and vegetable oil products consumption. In 2018, especially in
Indonesia, meat consumption increased by 12.5%, egg consumption increased by
6.64%, chicken consumption increased by 11.22% as compared to 2016 data
(Statistics Indonesia 2018). In recent years, livestock and poultry farming are
overgrowing, but it is likely to be adversely affected by climate change, competition
for land and water, and food security. The growth of livestock and poultry farming is
not accompanied by good waste management. Manure becomes one of the biggest
and most important waste in livestock and poultry farming. The impact of livestock
and poultry farming is not only on the soil and water environment but also on the
atmospheric environment. The effect on the air environment is from methane, carbon
dioxide, and nitrous oxide emissions that cause global warming. The livestock
farming contributes about 14.5% of total global emissions (Rojas-Downing et al.
2017). Further, about 27% of livestock emissions are in the form of carbon dioxide,
29% of livestock emissions as nitrous oxide, and 44% in the form of methane
(Fig. 10.3).
Tubiello et al. (2014) reported that the most significant global warming emission
comes from enteric fermentation, manure, and synthetic fertilizer (40%, 15%, and
13%, respectively). Greenhouse gases emissions from enteric fermentation consist of
methane produced in the digestive system of ruminants and to a lesser extent of
10 Tropical Biological Natural Resource Management Through Integrated. . .
223