(Table 11.6). However, the improvement of rice production is not improved by
biochar application in tidal swampland (potential acid sulfate soil), because the
production is already high even in the control. When rice husk biochar is applied
in peatland, corn yields increase up to 59% (Simatupang et al. 2017), and soybean
yields achieve 2.5–2.9 t ha
À1 (Endriani and Kurniawan 2018).
As a result, the nutrient content in biochar is generally low. Therefore, biochar
cannot directly increase the nutrient status in the soil and it needs to be combined
with other substances. The combination of rice husk biochar and straw compost is
better than a single application to increase soil fertility and soybean yields. A mixture
of 10 ton ha
À1 rice husk biochar and 10 ton ha
À1 straw compost increases soybean
yields by 41% compared to the control sample (Barus 2016). Nurida et al. (2015)
also reported that applying a formula consisting of 50% rice husk biochar + 50%
manure encouraged stable growth and soybean yields as much as 1.50 t ha
À1 in acid
upland.
11.6 Biochar Roles in Carbon Sequestration
and Greenhouse Gas Emission Mitigation
11.6.1 Biochar Roles in Carbon Sequestration
Carbon sequestration in soil is an important strategy on climate change mitigation
(Sohi et al. 2009; Widjaja 2002). As biochar decomposition is very slow in soil,
biochar can be stored for thousands of years (Vaegele 2013; Titiz and Sanford 2007;
Sohi et al. 2010). Thus, biochar is an important candidate for carbon sequestration
in soil.
When biochar is derived from biomass produced by combustion at temperatures
of 300–500
C under limited oxygen conditions, biochar even retains a highly
aromatic carbon structure with a high carbon concentration of 70–80% (Lehmann
and Rondon 2006). Biochar contains about 50% of carbon feedstock, while biochar
carbon by biological decomposition in soil usually decreases less than 20% C after
5–10 years (Lehmann and Rondon 2006). Whereas when biochar is produced under
low temperature conditions, the carbon in biochar remains only 3. Therefore, the
slash-and-burn system does not contribute significantly to carbon sequestration.
Biochar application increases soil carbon content in the suboptimal land of acid
upland soil, acid sulfate soil, and semi-arid soil (Table 11.7). The application of
10 t ha
À1 of coconut shell biochar and rice husk biochar in acid upland soil increased
carbon content by 38.78% and 70.40% compared to that of without the biochar
application (Endriani and Kurniawan 2018). In addition, the carbon content
increased by 25.4% with 40 t ha
À1 of cocoa shell biochar in acid upland soil
(Shalsabila et al. 2017). In acid sulfate soil, 10 t ha
À1 of rice husk biochar application
increased carbon content by 68.82% (Masulili et al. 2010).
352
E. Maftuah et al.
biochar application in tidal swampland (potential acid sulfate soil), because the
production is already high even in the control. When rice husk biochar is applied
in peatland, corn yields increase up to 59% (Simatupang et al. 2017), and soybean
yields achieve 2.5–2.9 t ha
À1 (Endriani and Kurniawan 2018).
As a result, the nutrient content in biochar is generally low. Therefore, biochar
cannot directly increase the nutrient status in the soil and it needs to be combined
with other substances. The combination of rice husk biochar and straw compost is
better than a single application to increase soil fertility and soybean yields. A mixture
of 10 ton ha
À1 rice husk biochar and 10 ton ha
À1 straw compost increases soybean
yields by 41% compared to the control sample (Barus 2016). Nurida et al. (2015)
also reported that applying a formula consisting of 50% rice husk biochar + 50%
manure encouraged stable growth and soybean yields as much as 1.50 t ha
À1 in acid
upland.
11.6 Biochar Roles in Carbon Sequestration
and Greenhouse Gas Emission Mitigation
11.6.1 Biochar Roles in Carbon Sequestration
Carbon sequestration in soil is an important strategy on climate change mitigation
(Sohi et al. 2009; Widjaja 2002). As biochar decomposition is very slow in soil,
biochar can be stored for thousands of years (Vaegele 2013; Titiz and Sanford 2007;
Sohi et al. 2010). Thus, biochar is an important candidate for carbon sequestration
in soil.
When biochar is derived from biomass produced by combustion at temperatures
of 300–500
C under limited oxygen conditions, biochar even retains a highly
aromatic carbon structure with a high carbon concentration of 70–80% (Lehmann
and Rondon 2006). Biochar contains about 50% of carbon feedstock, while biochar
carbon by biological decomposition in soil usually decreases less than 20% C after
5–10 years (Lehmann and Rondon 2006). Whereas when biochar is produced under
low temperature conditions, the carbon in biochar remains only 3. Therefore, the
slash-and-burn system does not contribute significantly to carbon sequestration.
Biochar application increases soil carbon content in the suboptimal land of acid
upland soil, acid sulfate soil, and semi-arid soil (Table 11.7). The application of
10 t ha
À1 of coconut shell biochar and rice husk biochar in acid upland soil increased
carbon content by 38.78% and 70.40% compared to that of without the biochar
application (Endriani and Kurniawan 2018). In addition, the carbon content
increased by 25.4% with 40 t ha
À1 of cocoa shell biochar in acid upland soil
(Shalsabila et al. 2017). In acid sulfate soil, 10 t ha
À1 of rice husk biochar application
increased carbon content by 68.82% (Masulili et al. 2010).
352
E. Maftuah et al.