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Herbicides are frequently used in the chemical control of weeds in various crops in Brazil and worldwide, so they are more frequently detected outside the application areas, contributing to the risk of environmental contamination. The importance of knowledge of the physicochemical properties of the environment and the pesticide used in the agricultural area is in order to understand its effects on terrestrial and aquatic ecosystems and the search for the prevention of future bioaccumulation potentials (bioconcentration and/or biomagnification) of molecules of pesticides in living nontarget organisms, minimizing their negative effects on the environment. The understanding of analytical techniques for measuring the quality of water resources as well as techniques for the remediation of contaminated water is essential to minimize the possible impacts caused by the application of pesticides to the environment.

Improved understanding of herbicide destinations, effects, and environmental risks through worldwide studies is crucial to minimizing impacts to nontarget organisms, especially in tropical regions rich in biodiversity. In recent years, there has been widespread international concern about the toxic effects of herbicides on humans, faunas, and native floras. Therefore, the adoption of agricultural practices that minimize the environmental effects of herbicides has been frequently studied, for example, the addition of biochar in agricultural soils. Biochar can be defined as the by-product of a thermal process conducted under low oxygen or oxygen-free conditions (pyrolysis) to convert plant biomass to biofuels, where biochar is the solid product of pyrolysis. The addition of biochar to the soil can easily potentiate the herbicide retention process, which, in addition to contributing positively to the reduction of chemical contaminants in the environment, may exert negative effects on herbicide behavior and the efficacy of these products on weed control. Thus, this chapter will present the general characteristics of biochar, as well as the impact of this material on sorption-desorption of herbicides in the soil.

The intensified use of pesticides and chemical fertilizers has resulted in threats to the environment. Thus it is crucial to the implementation of sustainable alternatives in order to mitigate the negative effects. The biofertilizer brings this proposal, as it improves soil fertility and minimize environmental risks. The ametryne herbicide is used for weed control, very soluble in water, bringing risks to terrestrial and aquatic ecosystem. Thus, the objective of this work was to study the degradation of ametryne in soil with the addition of liquid biofertilizers. After application of biofertilizer in soil with ametryne, the microbial activity increased in 39.149%, in CO2 generation. In the assay for quantification of ametryne by HPLC-MS/MS there was reduction of concentration of the molecule in the presence soil ISSN 2157-6092 2017 www.macrothink.org/jee 12 sample contaminated with the herbicide. Thus, the biofertilizer was able to assist in soil fertility, increasing metabolic activity, resulting in degradation of the herbicide. Journal of Environment and Ecology

In view of an environmental scenario of degradation of the terrestrial ecosystem due to the indiscriminate use of organic compounds, it is necessary to use complementary techniques to evaluate the remediation processes of contaminated soils. Thus, the objective of this work was to evaluate the biodegradation of ametryn herbicide, which is applied in sugarcane crops to control broadleaf weeds. The colorimetric assay was carried out by oxidation of 2.6-dichlorophenol-indophenol (DCPIP) in order to quantify the biodegradation of organic compounds present in the soil, in a short period of time. Another method used was the quantification of CO2 from the microbial respiration responsible for the metabolization of organic compounds in soil. The biodegradation of the ametryn herbicide was evaluated in soil, with the addition of microbial consortium as bioaumentation and addition of surfactant, as a form of microbial stimulation. It was observed that the addition of bioaumentation and biostimulation favored the increased metabolism of ametryn, reducing its residence time in the environment. The colorimetric assay is simple to perform, bringing rapid results. The respirometric assay is simple to perform, however, it has had long-term results. Thus, the use of a colorimetric assay as the primary evaluation of the biodegradation process of organic compounds and the use of the respirometric assay for the long-term evaluation of the metabolization process is suggested. Therefore, the use of complementary methods helps in understanding the process of biodegradation of organic compounds in the environment, as well as in the combination of factors that favor the mitigation of contaminated sites.

In recent years, pesticide application has increased worldwide due to the need for increased food production. In this way, understanding of the effects that these xenobiotic molecules can result in the soil microbiota becomes fundamental. Thus, this work aimed to evaluate microbial enzymatic activity by FDA, as well as quantify bacteria and fungi contaminated soil by ametryn herbicide. In addition, biofertilizer was added as a form of microbial biostimulation in order to cause enrichment of the affected site. The ametryn herbicide was chosen because it is widely used in sugarcane crops in Brazil, in the control of weeds, and is moderately persistent in the environment. It can be evaluated that the biofertilizer was fundamental in increasing the microbial activity of the soil, even in the presence of ametryn, probably contributing to its biodegradation. The estimation of the enzymatic activity by FDA, was essential for the evaluation of the increase of the microbial action, contributing to the verification of the active microbiota in the soil. It is suggested the application of biofertilizer in soils contaminated by ametryn, as a way to mitigate affected sites.

Concern about soil quality has been increasing due to environmental impacts from anthropogenic actions. The imbalance between its components alters activities in ecosystems. One of the main actions affecting soil quality is the presence of heavy metals, impairing the functioning of the ecosystem. This work evaluated the impacts of metal-contaminated soil on microbial activity after dam failure in Minas Gerais State, Brazil. Microbial respiration measurements and colony quantifications were used for evaluations. Thus, it is hoped that through these bioindicators, we can assess the quality of the environment and from these biostimulators restore the environmental balance, benefiting local communities affected by the disaster. After microbial biostimulation of the soil, there was an increase in the number of bacterial colonies as well as greater accumulation of CO2 over the days. Thus, the addition of nutrients to the metal-impacted soil was essential for initiating the restoration of the affected ecosystem equilibrium.