Chapter 12 - Biochar Is a Potential Source of Silicon Fertilizer: An Overview

Abstract

Silicon (Si) is considered the 2nd most abundant element present in the earth crust. Although Si is not an essential nutrient for plants, it is considered a highly beneficial element that plays an important role in soil–plant interactions, especially under stressful conditions. Plant available sources of Si in soil mainly include plant-derived Si (phytolith Si) and amorphous silica (ASi) with minor parts of microbial and protistic Si. In agricultural soils, phytolith Si is continuously removed due to the harvesting of the crops. Biochar is prepared from slow pyrolysis of organic materials, especially crop residues that are used for various purposes in agricultural soils, such as carbon sequestration, reduction of greenhouse gases, nutrient supply to plants, and minimization of pollutant toxicity to plants. Biochar prepared from Si-accumulator crops, such as rice and wheat straws, may contain higher concentrations of phytolith Si that might be a potential source of available Si for plants. In the present chapter, the possible sources of Si, its effects on crops, and possibility of biochar as a potential plant available Si have been discussed.