**5. Biochar prospects and essential research**

The global potential of biochar reaches far beyond *slash and char*. Inspired by the recreation of *Terra Preta*, most biochar research was restricted to the humid tropics. More information is needed on the agronomic potential of biochar, the potential to use alternative biomass sources (crop residues) and the production of by-products to evaluate the opportunities for adopting a biochar system on a global scale. Biochar as soil amendment needs to be studied in different climate and soil types. Today, crop residue biomass represents a considerable problem as well as new challenges and opportunities. A system converting biomass into energy (hydrogenrich gas) and producing biochar as a by-product might offer an opportunity to address these problems. Biochar can be produced by incomplete combustion from any biomass, and it is a by-product of the pyrolysis technology used for biofuel and ammonia production [56]. The acknowledgment of biochar as a carbon sink would facilitate C-trading mechanisms. Although most scientists agree that the half-life of biochar is in the range of centuries or millennia, a better knowledge of the biochar's durability in different ecosystems is important to achieve this goal. The systematic recycling of biochar in the environment has been depicted in **Figure 2**.

Access to the C trade market holds out the prospect to reduce or eliminate the deforestation of the primary forest because using intact primary forest would reduce the farmer's C credits. It is estimated the above-ground biomass of unlogged

forests to be 434 Mg ha<sup>−</sup><sup>1</sup> , about half of which is C. This C is lost if burned in the slash-and-burn scenario and lost at a high percentage if used for biochar production. The Trade could provide an to cease further deforestation; instead, reforestation and recuperation of degraded land for fuel and food crops would gain magnitude. As tropical forests account for between 20 and 25% of the world terrestrial C reservoir [57] this consequently reduces emissions from tropical forest conversion, which is estimated to contribute globally as much as 25% of the net CO2 emissions [58]. Today most biomass gasification systems tend to suppress the creation of residuals, like total organic carbon (TOC) and ashes. The C-emission trading options and a better knowledge of biochar as soil additive would add value to these residues. Further, this would facilitate the use of alternative biomass, those which are currently avoided due to their higher TOC residuals. The tarry vapors constitute a significant loss of carbon during carbonization [59] although representing another valuable product. Japanese researchers attempt to produce biochar with a specific pore size distribution to favor desired microorganisms. Pore structure, surface area, and adsorption properties are strongly influenced by the peak temperature during biochar production [59]. Increasing porosity is achieved with increasing temperature but the functional groups are gradually lost. In this context, it is also important to discern the mechanisms of nutrient retention (mainly N) due to biochar applications. The biochar's low biodegradability [60], low nutrient content [59], and high porosity and specific surface area [61] make biochar a rather exceptional SOM constituent. *Terra Preta's* research has shown that oxidation on the edges of the aromatic backbone and adsorption of other organic matter to biochar is responsible for the increased CEC, though the relative importance of these two processes remains unclear [21].

## **6. Conclusion**

Energy from crop residues could lower fossil energy consumption and CO2 emissions, and become a completely new income source for farmers and rural regions. A global analysis by revealed that up to 12% of the total anthropogenic C

**117**

**Author details**

Vishnu D. Rajput3

and Sukirtee6

Hanuman Singh Jatav1

Rostov-on-Don, Russia

hsjatav.soils@sknau.ac.in

\*, Satish Kumar Singh<sup>2</sup>

3 Academy of Biology and Biotechnology, Southern Federal University,

5 ICAR-Indian Grassland and Fodder Research Institute, Jhansi, India

\*Address all correspondence to: hanumaniasbhu@gmail.com;

4 ICAR-Vivekananda Parvatiya Krishi Anusandhan Sansthan, Almora, India

, Manoj Parihar4

Sciences, Banaras Hindu University, Varanasi, India

Haryana Agricultural University, Hissar, India

provided the original work is properly cited.

1 S.K.N. Agriculture University, Jobner, Rajasthan, India

, Surendra Singh Jatav2

. If the demand for renewable fuels by the

). The described mixture of driving forces

, Sonu Kumar Mahawer<sup>5</sup>

2 Department of Soil Science and Agricultural Chemistry, Institute of Agricultural

emissions by land-use change (0.21 Pg C) can be off-set annually in the soil if slash and burn are replaced by slash and char. Agricultural and forestry wastes add a

year 2100 was met through pyrolysis, biochar sequestration could exceed current

and technologies has the potential to use residual waste carbon-rich residues to

reshape agriculture, balance carbon and address nutrient depletion.

6 Department of Soil Science and Agricultural Chemistry, Chaudhary Charan Singh

© 2020 The Author(s). Licensee IntechOpen. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/ by/3.0), which permits unrestricted use, distribution, and reproduction in any medium,

,

, Rajesh Kumar Singhal5

*Importance of Biochar in Agriculture and Its Consequence*

*DOI: http://dx.doi.org/10.5772/intechopen.93049*

conservatively estimated 0.16 Pg C yr.<sup>−</sup><sup>1</sup>

emissions from fossil fuels (5.4 Pg C yr.<sup>−</sup><sup>1</sup>

### *Importance of Biochar in Agriculture and Its Consequence DOI: http://dx.doi.org/10.5772/intechopen.93049*

emissions by land-use change (0.21 Pg C) can be off-set annually in the soil if slash and burn are replaced by slash and char. Agricultural and forestry wastes add a conservatively estimated 0.16 Pg C yr.<sup>−</sup><sup>1</sup> . If the demand for renewable fuels by the year 2100 was met through pyrolysis, biochar sequestration could exceed current emissions from fossil fuels (5.4 Pg C yr.<sup>−</sup><sup>1</sup> ). The described mixture of driving forces and technologies has the potential to use residual waste carbon-rich residues to reshape agriculture, balance carbon and address nutrient depletion.
