11.4.2 Chemical Property Improvement
It is expected that biochar will be able to improve the soil chemical properties in
suboptimal land. However, because the biochar contains very few nutrients while its
volume in soil is very low, it was found that biochar materials cannot change the soil
nutrient structure solely (Table 11.4). However, only in acid soil (land), total N and
Exch.-K
+ in soil are increased by biochar application (Putri and Mukhlis 2017), but
the mechanism for the increase is unclear. As total N in soil increases, N 2 fixing is
activated, NH 4
+ is changed with K
+ , of which mechanisms are only hypotheses, then
further studies are required. When biochar is applied to sandy loam in West Nusa
Tenggara, the soil pH and soil CEC increase, because the sandy loam is extremely
low in pH (in the absence of cation) and CEC (CEC sites are absent due to the silicate
composition) (Sukartono and Utomo 2012). Thus, basically biochar slightly affects
the soil chemical properties because the nutrient content and CEC are lower compared with that of the soil clay.
11.4.3 Biological Property Improvement
Biochar is a good matrix for microbe growth, especially bacteria, actinomycetes,
and arbuscular mycorrhizal fungi. Biochar matrix is good for microbe colonization
and adsorbed nutrients supplying to microbes (Lehmann and Rondon 2006; Thies
and Rillig 2009). Biochar application significantly changes the population and
diversity of microorganisms, fungal bacteria composition, and the dominant (Thies
and Rillig 2009). When maize stalk biochar and cotton stalk biochar were applied to
groundnut plants in Alfisol (semi-arid of India), the population of bacteria and fungi
increased (Pandian et al. 2016) (Table 11.5). The active microbial biomass increased
coupled with an increase in Eichornia biochar application rate in Red soil (semi-arid
of India) (Masto et al. 2013) (Table 11.5).
In humic acrisols (Kenya), N fix is greatly activated in common bean plants
(Phaseolus vulgaris) by several biochar species, including rice biochar, bagasse
biochar, maize stover biochar, maize cob biochar, eucalyptus biochar, Delonix
biochar, and tea biochar (Güereña et al. 2015). Tea biochar application showed
high nodule formation in legume common bean plants. The research used a nodulin
and non-nodulin isolate of beans (Phaseolus vulgaris), the DOR 364 variety from the
International Center for Tropical Agriculture, Cali, Columbia (Güereña et al. 2015).
The non-nodulating isoline was used to quantify soil 15 N uptake values to determine N derived from fixation (Ndfa) via the natural abundance method (Peoples
et al. 2009).
As biochar application influences soil microbial diversity, the relative abundance
of several microbes affects the carbon and nitrogen metabolisms in soil, which
stimulate nitrification and denitrification processes and reduce N 2 O emissions
(Xu et al. 2014). Biochar acts as a microbial carrier (inoculum), which can be
348
E. Maftuah et al.
It is expected that biochar will be able to improve the soil chemical properties in
suboptimal land. However, because the biochar contains very few nutrients while its
volume in soil is very low, it was found that biochar materials cannot change the soil
nutrient structure solely (Table 11.4). However, only in acid soil (land), total N and
Exch.-K
+ in soil are increased by biochar application (Putri and Mukhlis 2017), but
the mechanism for the increase is unclear. As total N in soil increases, N 2 fixing is
activated, NH 4
+ is changed with K
+ , of which mechanisms are only hypotheses, then
further studies are required. When biochar is applied to sandy loam in West Nusa
Tenggara, the soil pH and soil CEC increase, because the sandy loam is extremely
low in pH (in the absence of cation) and CEC (CEC sites are absent due to the silicate
composition) (Sukartono and Utomo 2012). Thus, basically biochar slightly affects
the soil chemical properties because the nutrient content and CEC are lower compared with that of the soil clay.
11.4.3 Biological Property Improvement
Biochar is a good matrix for microbe growth, especially bacteria, actinomycetes,
and arbuscular mycorrhizal fungi. Biochar matrix is good for microbe colonization
and adsorbed nutrients supplying to microbes (Lehmann and Rondon 2006; Thies
and Rillig 2009). Biochar application significantly changes the population and
diversity of microorganisms, fungal bacteria composition, and the dominant (Thies
and Rillig 2009). When maize stalk biochar and cotton stalk biochar were applied to
groundnut plants in Alfisol (semi-arid of India), the population of bacteria and fungi
increased (Pandian et al. 2016) (Table 11.5). The active microbial biomass increased
coupled with an increase in Eichornia biochar application rate in Red soil (semi-arid
of India) (Masto et al. 2013) (Table 11.5).
In humic acrisols (Kenya), N fix is greatly activated in common bean plants
(Phaseolus vulgaris) by several biochar species, including rice biochar, bagasse
biochar, maize stover biochar, maize cob biochar, eucalyptus biochar, Delonix
biochar, and tea biochar (Güereña et al. 2015). Tea biochar application showed
high nodule formation in legume common bean plants. The research used a nodulin
and non-nodulin isolate of beans (Phaseolus vulgaris), the DOR 364 variety from the
International Center for Tropical Agriculture, Cali, Columbia (Güereña et al. 2015).
The non-nodulating isoline was used to quantify soil 15 N uptake values to determine N derived from fixation (Ndfa) via the natural abundance method (Peoples
et al. 2009).
As biochar application influences soil microbial diversity, the relative abundance
of several microbes affects the carbon and nitrogen metabolisms in soil, which
stimulate nitrification and denitrification processes and reduce N 2 O emissions
(Xu et al. 2014). Biochar acts as a microbial carrier (inoculum), which can be
348
E. Maftuah et al.