Keywords AeroHydro culture · Suboptimal land · Microorganism matrix · Water
holding capacity · Carbon sequestration
11.1 Introduction
In Indonesia, suboptimal land consists of 107.4 million ha for acid upland and 33.4
million ha for swampland (Ritung et al. 2015). Some problems in the development of
suboptimal land include the soil acidity, low nutrient availability, and low organic
carbon content (Mulyani and Sarwani 2013).
Land quality is a complex attribute of land that has a specific role in determining
the level of its suitability for a certain use (Permentan 2013). Land quality is related
to crop production, including the physical, chemical, and biological properties of the
soil that affect plant growth. Taylor et al. (2010) summarize soil quality parameters
whose changes significantly affect plant growth. These parameters include pH, total
nitrogen, available phosphor (P), potassium (K), calcium (Ca), iron (Fe), and
aluminum (Al).
Suboptimal land quality is commonly poor so that it requires appropriate management. In addition, the continuous application of soil amendment and inorganic
fertilizer can cause a decrease in soil organic C content, compaction, or damage to
soil structure, and a decrease in land productivity (Ge et al. 2008). Applying soil
amendments can improve suboptimal land quality. Biochar is an alternative substance to improve the soil quality and the environment, which is inexpensive,
sustainable, and environmentally friendly.
Biochar can improve soil chemical properties including cation exchange capacity
(CEC) (Van Zwieten et al. 2010), increase nutrient and water retention (Laird et al.
2010; Schulz and Glaser 2012; Zhang et al. 2013), and reduce soil acidity (Li-li et al.
2016). Biochar can reduce N fertilizer loss (Steiner et al. 2007) and nutrient leaching
(Novak et al. 2009; Yao et al. 2012; Widowati et al. 2012). The micropores in
biochar structures are able to increase water holding capacity (Santi and Goenadi
2010; Sutono and Nurida 2012; Sukartono and Utomo 2012; Yu et al. 2013) and
reduce nitrogen runoff (Clough et al. 2013; Knowles et al. 2011; Gao and DeLuca
2016).
Biochar can also be used as an effective matrix for microbes which play an
important role in the soil to be utilized in the production of biological fertilizer (Santi
and Goenadi 2010). Fungi can sporulate in the biochar microspores because in these
pores the competition among other saprophytes is quite low (Saito and Marumoto
2002). Biochar can increase the diversity of microorganisms in the soil (Li-li et al.
2016). Biochar can be a habitat for soil microbes, but it takes time for the microbes to
consume it. As a result, the applied biochar will be left in the soil for a long time.
There have been many studies stating the positive response of biochar application
to soil fertility. Nevertheless, it should be noted that not all types of biochar have the
same characteristics. The chemical and physical properties of biochar are strongly
influenced by its feedstock and the conditions of the pyrolysis process such as the
338
E. Maftuah et al.
holding capacity · Carbon sequestration
11.1 Introduction
In Indonesia, suboptimal land consists of 107.4 million ha for acid upland and 33.4
million ha for swampland (Ritung et al. 2015). Some problems in the development of
suboptimal land include the soil acidity, low nutrient availability, and low organic
carbon content (Mulyani and Sarwani 2013).
Land quality is a complex attribute of land that has a specific role in determining
the level of its suitability for a certain use (Permentan 2013). Land quality is related
to crop production, including the physical, chemical, and biological properties of the
soil that affect plant growth. Taylor et al. (2010) summarize soil quality parameters
whose changes significantly affect plant growth. These parameters include pH, total
nitrogen, available phosphor (P), potassium (K), calcium (Ca), iron (Fe), and
aluminum (Al).
Suboptimal land quality is commonly poor so that it requires appropriate management. In addition, the continuous application of soil amendment and inorganic
fertilizer can cause a decrease in soil organic C content, compaction, or damage to
soil structure, and a decrease in land productivity (Ge et al. 2008). Applying soil
amendments can improve suboptimal land quality. Biochar is an alternative substance to improve the soil quality and the environment, which is inexpensive,
sustainable, and environmentally friendly.
Biochar can improve soil chemical properties including cation exchange capacity
(CEC) (Van Zwieten et al. 2010), increase nutrient and water retention (Laird et al.
2010; Schulz and Glaser 2012; Zhang et al. 2013), and reduce soil acidity (Li-li et al.
2016). Biochar can reduce N fertilizer loss (Steiner et al. 2007) and nutrient leaching
(Novak et al. 2009; Yao et al. 2012; Widowati et al. 2012). The micropores in
biochar structures are able to increase water holding capacity (Santi and Goenadi
2010; Sutono and Nurida 2012; Sukartono and Utomo 2012; Yu et al. 2013) and
reduce nitrogen runoff (Clough et al. 2013; Knowles et al. 2011; Gao and DeLuca
2016).
Biochar can also be used as an effective matrix for microbes which play an
important role in the soil to be utilized in the production of biological fertilizer (Santi
and Goenadi 2010). Fungi can sporulate in the biochar microspores because in these
pores the competition among other saprophytes is quite low (Saito and Marumoto
2002). Biochar can increase the diversity of microorganisms in the soil (Li-li et al.
2016). Biochar can be a habitat for soil microbes, but it takes time for the microbes to
consume it. As a result, the applied biochar will be left in the soil for a long time.
There have been many studies stating the positive response of biochar application
to soil fertility. Nevertheless, it should be noted that not all types of biochar have the
same characteristics. The chemical and physical properties of biochar are strongly
influenced by its feedstock and the conditions of the pyrolysis process such as the
338
E. Maftuah et al.