Details

Autor(en) / Beteiligte

• Jones, D.L.
• Edwards-Jones, G.
• Murphy, D.V.

Titel

Biochar mediated alterations in herbicide breakdown and leaching in soil

Ist Teil von

• Soil biology & biochemistry, 2011-04, Vol.43 (4), p.804-813

Ort / Verlag

Amsterdam: Elsevier Ltd

Erscheinungsjahr

2011

Quelle

Access via ScienceDirect (Elsevier)

Beschreibungen/Notizen

• Biochar application to soil has been proposed as a mechanism for improving soil quality and the long term sequestration of carbon. The implications of biochar on pesticide behavior, particularly in the longer term, however, remains poorly understood. Here we evaluated the influence of biochar type, time after incorporation into soil, dose rate and particle size on the sorption, biodegradation and leaching of the herbicide simazine. We show that typical agronomic application rates of biochar (10–100 t ha −1) led to alterations in soil water herbicide concentrations, availability, transport and spatial heterogeneity. Overall, biochar suppressed simazine biodegradation and reduced simazine leaching. These responses were induced by a rapid and strong sorption of simazine to the biochar which limits its availability to microbial communities. Spatial imaging of 14C-labeled simazine revealed concentrated hotpsots of herbicide co-localized with biochar in the soil profile. The rate of simazine mineralization, amount of sorption and leaching was inversely correlated with biochar particle size. Biochar aged in the field for 2 years had the same effect as fresh biochar on the sorption and mineralization of simazine, suggesting that the effects of biochar on herbicide behavior may be long lasting. We conclude that biochar application to soil will reduce the dissipation of foliar applied pesticides decreasing the risk of environmental contamination and human exposure via transfer in the food chain, but may affect the efficacy of soil-applied herbicides. ► Biochar sequesters carbon in soil and significantly affects pesticide behavior. ► Biochar prevents pesticide leaching but enhances pesticide persistence in soil. ► Pesticides preferentially associate with biochar causing concentrated hotspots in soil. ► The effect of biochar on pesticide behavior lasts for long periods in soil (>2 years). ► Biochar may potentially suppress the effectiveness of pre-emergent herbicides in soil.