Biochar is produced from the pyrolysis of carbon-rich plant- and animal-residues under low oxygen and high temperature conditions and has been increasingly used for its positive role in soil compartmentalization throu...Biochar is produced from the pyrolysis of carbon-rich plant- and animal-residues under low oxygen and high temperature conditions and has been increasingly used for its positive role in soil compartmentalization through activities such as carbon sequestration and improving soil quality. Biochar is also considered a unique adsorbent due to its high specific surface area and highly carbonaceous nature. Therefore, soil amendments with small amounts of biochar could result in higher adsorption and, consequently, decrease the bioavailability of contaminants to microbial communities, plants, earthworms, and other organisms in the soil. However, the mechanisms affecting the environmental fate and behavior of organic contaminants, especially pesticides in biochar-amended soil, are not well understood. The purpose of this work is to review the role of biochar in primary processes, such as adsorption–desorption and leaching of pesticides. Biochar has demonstrable effects on the fate and effects of pesticides and has been shown to affect the degradation and bioavailability of pesticides for living organisms. Moreover, some key aspects of agricultural and environmental applications of biochar are highlighted.展开更多
Biochar has been introduced as an acceptable soil amendment due to its environmental benefits such as sequestering soil contaminants. However, the aging process in biochar amended soil probably decreases the adsorptio...Biochar has been introduced as an acceptable soil amendment due to its environmental benefits such as sequestering soil contaminants. However, the aging process in biochar amended soil probably decreases the adsorption capacity of biochar through changing its physico-chemical properties. Adsorption, leaching and bioavailability of fomesafen to corn in a Chinese soil amended by rice hull biochar after 0, 30, 90 and 180 days were investigated. Results showed that the addition of 0.5%-2% fresh biochar significantly increases the adsorption of fomesafen 4-26 times compare to unamended soil due to higher SSA of biochar. Biochar amendment also decreases fomesafen concentration in soil pore water by 5%-23% resulting lower risk of the herbicide for cultivated plants. However, the aging process decreased the adsorption capacity ofbiochar since the adsorption coefficient values which was 1.9-12.4 in 0.5%-2% fresh biochar amended soil, declined to 1.36-4.16, 1.13-2.78 and 0.95-2.31 in 1, 3 and 6-month aged treatments, respectively. Consequently, higher desorption, leaching and bioavailable fraction of fomesafen belonged to 6-month aged treatment. Nevertheless, rice hull biochar was effective for sequestering fomesafen as the adsorption capacity of biochar amended soil after 6 months of aging was still 2.5-5 times hi^her compared to that of unamended soil.展开更多
Combined toxicity of herbicides to non-target crops is usually resulted from their successive application.The present study was conducted to assess the combined toxicity of flufenacet（FLU）and imazaquin（IMA）to sorg...Combined toxicity of herbicides to non-target crops is usually resulted from their successive application.The present study was conducted to assess the combined toxicity of flufenacet（FLU）and imazaquin（IMA）to sorghum with their concentration in soil pore water.The concentrations that inhibited growth by 50%（IC50）of FLU and IMA individually and their combination estimated from the herbicide concentrations in soil pore water notably differed from those based on the amended concentrations,due to the decline in bioavailability resulting from adsorption of the herbicides onto soil.According to the amended concentrations,the combined effect of FLU and IMA in soil on sorghum growth was identified as additive action.Based on the concentration in soil pore water,however,it was determined to be antagonism,which was identical to that observed in a test using culture solution.The results revealed that pore water herbicide concentration might be an effective tool to assess the combined toxicity of herbicides in soil to rotational crops.展开更多
基金supported by the National High Technology R&D Program of China (No. 2013AA065202)Zhejiang Provincial Natural Science Foundation (No. LZ13D010001)+1 种基金the National Natural Science Foundation of China (Nos. 41271489 and 21477112)the Specialized Research Fund for the Doctoral Program of Higher Education (No. 20120101110073)
文摘Biochar is produced from the pyrolysis of carbon-rich plant- and animal-residues under low oxygen and high temperature conditions and has been increasingly used for its positive role in soil compartmentalization through activities such as carbon sequestration and improving soil quality. Biochar is also considered a unique adsorbent due to its high specific surface area and highly carbonaceous nature. Therefore, soil amendments with small amounts of biochar could result in higher adsorption and, consequently, decrease the bioavailability of contaminants to microbial communities, plants, earthworms, and other organisms in the soil. However, the mechanisms affecting the environmental fate and behavior of organic contaminants, especially pesticides in biochar-amended soil, are not well understood. The purpose of this work is to review the role of biochar in primary processes, such as adsorption–desorption and leaching of pesticides. Biochar has demonstrable effects on the fate and effects of pesticides and has been shown to affect the degradation and bioavailability of pesticides for living organisms. Moreover, some key aspects of agricultural and environmental applications of biochar are highlighted.
基金supported by the National High Technology R&D Program of China(Nos.2013AA102804,2012AA06A204)the National Natural Science Foundation of China(Nos.21177111,41271489)Zhejiang Provincial Natural Science Foundation(No.LZ13D010001)
文摘Biochar has been introduced as an acceptable soil amendment due to its environmental benefits such as sequestering soil contaminants. However, the aging process in biochar amended soil probably decreases the adsorption capacity of biochar through changing its physico-chemical properties. Adsorption, leaching and bioavailability of fomesafen to corn in a Chinese soil amended by rice hull biochar after 0, 30, 90 and 180 days were investigated. Results showed that the addition of 0.5%-2% fresh biochar significantly increases the adsorption of fomesafen 4-26 times compare to unamended soil due to higher SSA of biochar. Biochar amendment also decreases fomesafen concentration in soil pore water by 5%-23% resulting lower risk of the herbicide for cultivated plants. However, the aging process decreased the adsorption capacity ofbiochar since the adsorption coefficient values which was 1.9-12.4 in 0.5%-2% fresh biochar amended soil, declined to 1.36-4.16, 1.13-2.78 and 0.95-2.31 in 1, 3 and 6-month aged treatments, respectively. Consequently, higher desorption, leaching and bioavailable fraction of fomesafen belonged to 6-month aged treatment. Nevertheless, rice hull biochar was effective for sequestering fomesafen as the adsorption capacity of biochar amended soil after 6 months of aging was still 2.5-5 times hi^her compared to that of unamended soil.
基金supported by the National High Technology R&D Program of China(No.2013AA065202)the National Natural Science Foundation of China(Nos.41271489,21477112)+1 种基金the Zhejiang Provincial Natural Science Foundation(No.LZ13D010001)Specialized Research Fund for the Doctoral Program of Higher Education(No.20120101110073)
文摘Combined toxicity of herbicides to non-target crops is usually resulted from their successive application.The present study was conducted to assess the combined toxicity of flufenacet（FLU）and imazaquin（IMA）to sorghum with their concentration in soil pore water.The concentrations that inhibited growth by 50%（IC50）of FLU and IMA individually and their combination estimated from the herbicide concentrations in soil pore water notably differed from those based on the amended concentrations,due to the decline in bioavailability resulting from adsorption of the herbicides onto soil.According to the amended concentrations,the combined effect of FLU and IMA in soil on sorghum growth was identified as additive action.Based on the concentration in soil pore water,however,it was determined to be antagonism,which was identical to that observed in a test using culture solution.The results revealed that pore water herbicide concentration might be an effective tool to assess the combined toxicity of herbicides in soil to rotational crops.
