production process largely determines the resulting C, pH, and CEC of the biochar
(Chen et al. 2008; Van Zwieten et al. 2010). The chemical properties of biochar are
strongly influenced by its feedstock (Table 11.2). Rice husk biochar contains the
highest SiO 2 at 34.83%, while other biochar ranges from 2–6.3% (Table 11.2).
Biochar from organic fertilizer and waste usually has a very high ash content.
Chicken manure biochar has 45% ash from its feedstock (Koutcheiko et al. 2007),
and bone biochar contains minerals which account for 84% of minerals from
feedstock (Purevsuren et al. 2004). The highest ash content is in palm kernel biochar,
while the lowest is in bamboo biochar. Bamboo biochar contains the highest organic
C content (50.03%), while the lowest (23.73%) is in palm kernel biochar. Palm oil
waste has a fairly large content of carbon (43–51% by weight) and fixed carbon
(30–39% by weight), about 3% of ash, and a very high surface area of 210 m
2 g
À1
(Liewa et al. 2018). The pH is very high, more than 8.0, then biochar is useful to
amend low pH soil. CEC is extremely high in rice husk, then both biochars are
expected as good materials for nutrient adsorption. As N is 0.5~1.3%, P is 0.4~0.5%,
N and P concentration are low in these biochars. However, K concentration is high,
39% in palm fruit bunches, bamboo, and coconut shell, which are good materials for
K deficiency soil, especially for peat soil. Mg concentration is only high, 4% in
coconut shell, then the coconut shell is a good biochar to Mg supplying to peat soil.
Fe concentration is extremely high in all biochars except for palm kernel biochar,
then the main micronutrients, especially Fe, will be enough from these biochars.
Thus, after reviewing the chemical aspect on biochar, the biochars produced from
rice husk and palm fruit bunches, bamboo, and coconut shell are functional to
improve soil chemical conditions. All species biochars contribute basically to
improve pH, CEC, and micronutrients (mainly Fe, also other micronutrients because
micronutrient deficiency leads to infertile fruits and grains). High pH biochar is more
suitable for a bacterial habitat (Santos et al. 2012; Zimmermann et al. 2012; Farrell
et al. 2013).
Based on Fig. 11.2, all types of biochar have absorption spectral bands below
900 cm
À1 that indicate minerals from the feedstock. Carboxylate and phenolate
groups are often found in Melaleuca leucadendron stem biochar, followed by
biochar from coconut shells. The lignin content in biochar ranges from 5 to 22%.
The presence of aromatic esters is the highest in coconut shell biochar. All types of
biochar show a high content of waxes, lipids ranging from 10 to 40%. They also
contain cellulose, which is indicated by absorption at a wavelength of
3300–3800 cm
À1 . Biochar from coconut shell has the most diverse functional groups
such as phenolics, phenol, aromatic esters, high mineral content, carboxylates,
protein, lignin, fats, waxes, lipids, and cellulose. The lowest number of functional
groups is found in rice husk biochar which is dominated by fat, wax, and lipid
groups. Based on NMR analysis, biochar produced at 350–500
C is dominated by
aromatic (aryl) C and low H/C ratio. However, the characteristics of the feedstock
are still maintained at this temperature. Pyrolysis at temperatures above 500
C tends
to eliminate the functional group C structure from its feedstock (Krull et al. 2009).
11 Biochar for the Improvement of Peatland and Suboptimal Land
343
(Chen et al. 2008; Van Zwieten et al. 2010). The chemical properties of biochar are
strongly influenced by its feedstock (Table 11.2). Rice husk biochar contains the
highest SiO 2 at 34.83%, while other biochar ranges from 2–6.3% (Table 11.2).
Biochar from organic fertilizer and waste usually has a very high ash content.
Chicken manure biochar has 45% ash from its feedstock (Koutcheiko et al. 2007),
and bone biochar contains minerals which account for 84% of minerals from
feedstock (Purevsuren et al. 2004). The highest ash content is in palm kernel biochar,
while the lowest is in bamboo biochar. Bamboo biochar contains the highest organic
C content (50.03%), while the lowest (23.73%) is in palm kernel biochar. Palm oil
waste has a fairly large content of carbon (43–51% by weight) and fixed carbon
(30–39% by weight), about 3% of ash, and a very high surface area of 210 m
2 g
À1
(Liewa et al. 2018). The pH is very high, more than 8.0, then biochar is useful to
amend low pH soil. CEC is extremely high in rice husk, then both biochars are
expected as good materials for nutrient adsorption. As N is 0.5~1.3%, P is 0.4~0.5%,
N and P concentration are low in these biochars. However, K concentration is high,
39% in palm fruit bunches, bamboo, and coconut shell, which are good materials for
K deficiency soil, especially for peat soil. Mg concentration is only high, 4% in
coconut shell, then the coconut shell is a good biochar to Mg supplying to peat soil.
Fe concentration is extremely high in all biochars except for palm kernel biochar,
then the main micronutrients, especially Fe, will be enough from these biochars.
Thus, after reviewing the chemical aspect on biochar, the biochars produced from
rice husk and palm fruit bunches, bamboo, and coconut shell are functional to
improve soil chemical conditions. All species biochars contribute basically to
improve pH, CEC, and micronutrients (mainly Fe, also other micronutrients because
micronutrient deficiency leads to infertile fruits and grains). High pH biochar is more
suitable for a bacterial habitat (Santos et al. 2012; Zimmermann et al. 2012; Farrell
et al. 2013).
Based on Fig. 11.2, all types of biochar have absorption spectral bands below
900 cm
À1 that indicate minerals from the feedstock. Carboxylate and phenolate
groups are often found in Melaleuca leucadendron stem biochar, followed by
biochar from coconut shells. The lignin content in biochar ranges from 5 to 22%.
The presence of aromatic esters is the highest in coconut shell biochar. All types of
biochar show a high content of waxes, lipids ranging from 10 to 40%. They also
contain cellulose, which is indicated by absorption at a wavelength of
3300–3800 cm
À1 . Biochar from coconut shell has the most diverse functional groups
such as phenolics, phenol, aromatic esters, high mineral content, carboxylates,
protein, lignin, fats, waxes, lipids, and cellulose. The lowest number of functional
groups is found in rice husk biochar which is dominated by fat, wax, and lipid
groups. Based on NMR analysis, biochar produced at 350–500
C is dominated by
aromatic (aryl) C and low H/C ratio. However, the characteristics of the feedstock
are still maintained at this temperature. Pyrolysis at temperatures above 500
C tends
to eliminate the functional group C structure from its feedstock (Krull et al. 2009).
11 Biochar for the Improvement of Peatland and Suboptimal Land
343