The Effect of Two Types of Biochars on the Efficacy, Emission, Degradation, and Adsorption of the Fumigant Methyl Isothiocyanate

Abstract

Biochar (BC) is increasingly applied in agriculture; however, due to its adsorption and degradation properties, biochar may also affect the efficacy of fumigant in amended soil. Our research is intended to study the effects of two types of biochars (BC-1 and BC-2) on the efficacy and emission of methyl isothiocyanate (MITC) in biochar amendment soil. Both types of biochars can significantly reduce MITC emission losses, but, at the same time, decrease the concentration of MITC in the soil. The efficacy of MITC for controlling soil-borne pests (Meloidogyne spp., Fusarium spp. Phytophthora spp., Abutilon theophrasti and Digitaria sanguinalis) was reduced when the biochar (BC-1 and BC-2) was applied at a rate of higher than 1% and 0.5% (on a weight basis) (on a weight basis), respectively. However, increased doses of dazomet (DZ) were able to offset decreases in the efficacy of MITC in soils amended with biochars. Biochars with strong adsorption capacity (such as BC-1) substantially reduced MITC degradation rate by 6.2 times, and increased by 4.1 times following amendment with biochar with high degradability (e.g., BC-2), compared to soil without biochar amendment. This is due to the adsorption and degradation of biochar that reduces MITC emission losses and pest control.

Impact of Biochar on Rhizosphere Bacterial Diversity Restoration Following Chloropicrin Fumigation of Planted Soil

“…The biochar produced by Ageratina adenophora in this study has a high specific surface area of 162.18 m −2 ·g −1 , which may create a more favorable and separate pore habitat in the root zone and benefit the restoration of microorganisms [ 40 ]. Previous studies in our laboratory have shown that the characteristics of biochar can accelerate the release of the inhibitory effect of fumigants on microorganisms [ 16 , 41 ]. The finding that biochar can accelerate the recovery of rhizobacterial diversity is similar to the study in the bulk soil by Fang et al [ 20 ], who found that 5% biochar amendment could counteract the inhibitory effect on bulk soil bacterial diversity.…”

“…For example, compared with the high biochar application rate (5%) in the study by Fang et al, the 2% biochar addition rate in this study is only at a medium level [ 42 ]. Previous studies have shown that the addition of biochar before soil fumigation can accelerate the degradation of the fumigant and may lead to a decrease in fumigation efficacy, resulting in the rapid release of microbial inhibition [ 16 , 17 ]. In addition, rhizobacterial diversity had a brief peak at 30 d, especially in OTU richness, which may be susceptible to the nutrients provided by biochar.…”

“…As a soil amendment agent, biochar has been described as a possible substance to improve soil fertility and mitigate climate change [ 15 ]. Previous studies have shown that biochar amendments after soil fumigation can significantly reduce the emissions of fumigants into the atmosphere [ 16 ]. Liu et al [ 17 ] found that biochar can accelerate the degradation of CP and is beneficial for removing fumigants thoroughly from the soil.…”

Biomass Chars: Elaboration, Characterization and Applications

“…In their research, Fang et al [3] have intended to study the effects of two types of biochars (BC-1 and BC-2) on the efficacy and emission of methyl isothiocyanate (MITC) in biochar amendment soil. Both types of biochars can significantly reduce MITC emission losses, but, at the same time, decrease the concentration of MITC in the soil.…”

“…This book contains the successful invited submissions [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15] to a Special Issue of Energies on the subject area of "Biomass Chars: Elaboration, Characterization, and Applications". The invited editors have decided to focus the Special Issue on the specific topic of biomass transformation and use.…”