Nanoparticles as a carrier of herbicides applied in pre-emergency system in soils derived from no-tillage and conventional

Abstract

Herbicides are the class of pesticides most widely used in Brazil. Without the use of these products reductions in agricultural productivity can reach 40%. In addition, these compounds are the most reported outside the application areas, such as environmental contaminants. If applied in the soil the herbicides are more exposed to the processes of dissipation in the environment, often reaching groundwater and superficial or remain for a long time persistent in the environment, as well as being able to have reduced efficiency in weed management. In this premise, the development of technologies that reduce risks and increase the efficiency of herbicides meet the current needs of agriculture, greater optimization of processes and rationalization of resources. Therefore, the present PhD project aims at the development of a system of nanoparticles prepared with biodegradable materials that allows the reduction of the environmental risk of metribuzin and indaziflam, without their efficiency being reduced and their persistence increasing in the environment. In addition, we seek to understand the possible changes in soil behavior of encapsulated herbicides and control efficiency in different soil types (from no-tillage and conventional systems). The studies will consist of a stage of formulation, characterization and choice of the best nanoparticle system for herbicides and a stage where the behavior of the products in the soil will be observed through leaching, sorption-desorption and biodegradation studies. In addition, studies of control efficacy and root absorption will be performed. In the second step, all studies will involve the use of radiometric techniques, as an important tool in the diagnosis of the behavior of encapsulated herbicides. Thus, it is possible to obtain stable nanoparticles, that is, with good physicochemical properties and potential for weed management. As well, to contribute with studies that aim the use of nanotechnology in agriculture for a better understanding of the dynamics of these nanocarriers in the soil and the control of weeds. (AU)