Biochar impact on herbicides behavior in the soils: an approach in Brazil

Abstract

The application of biochar to soils because of beneficial effects is proven by many international researchers and this can increase herbicides sorption and reduce effectiveness on weed management. Positive impacts are reported in relation to the environmental behavior of herbicides, since the increase of the sorption reduces the leaching of these products to groundwater. Negative impacts are reported in relation to agronomic management of herbicides, since the sorption increase reduces the availability of these products in the soil, reducing the residual effect for weed control. In Brazil, biochar is produced by several private companies and pyrolysis units, but the cost for production is still very high, probably due to lack of government incentive, low use of producers, and awareness of the benefits. Although biochar has been used for several decades in other countries, in Brazil there are still few studies developed by soil researchers, and biochar efficiency on the bioavailability of herbicide in the soil is still unknown by many weed science Brazilian researchers. Against the above, the objective of this review was to evaluate the bioavailability of herbicides in biochar-amended soils and highlight the research with biochar in Brazilian conditions, besides presenting the benefits to soil with biochar addition. Little is known about the herbicides behavior in Brazilian soils amended with biochar, which can be used with greater intensity in modern agriculture. So more research is needed under our conditions to really we understand the dynamics of this product in the soil.