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Herbicides are pivotal in modern agriculture, efficiently managing weeds and supporting sustainable farming. One of such herbicides is 2,4-dichlorophenoxyacetic acid (2,4-D), a synthetic auxin that targets broad-leaved weeds. It's praised for controlling various weeds with minimal injury to monocot plants. Innovative delivery methods for 2,4-D, like slow release and targeted systems, offer benefits such as extended herbicide release and reduced environmental impact. This review assesses diverse 2,4-D delivery systems: biochar, silica, layered inorganic materials, polymers, and gels, analyzing their benefits and limitations. Success in these systems relies on finding the optimal balance between strong herbicide bonding for high loading efficiency and the controlled release necessary for the desired herbicidal action. Porous materials adapt porosity for this equilibrium, and organic formulations optimize bonding groups. Layered materials, especially hydroxide ones, show potential by attracting 2,4-D anions. Controlled release is critical; Si-based systems achieve pH-controlled release, while polymers rely on hydrolysis modulated by temperature and acidity. Moreover, light-responsive groups offer precise control over 2,4-D distribution via irradiation. These studies highlight how inventive materials and techniques can transform agrochemicals. Ongoing research and development in this field will further enhance the efficiency, sustainability, and safety of herbicide delivery, benefiting agricultural practices and environmental stewardship. [Display omitted] • Review of 2,4-D delivery systems: biochar, silica, layered inorganics, polymers, gels. • Balancing herbicide bonding for high efficiency and controlled release is crucial. • Functional groups in organic formulations optimize bonding and control release. • Positively charged layers attract 2,4-D anions, enhancing loading efficiency. • Polymers control 2,4-D release via hydrolysis modulated by temperature and acidity. [ABSTRACT FROM AUTHOR]

The influence of exogenous form of heavy metals intake on their transformation in the soil is determined during model experiments. Distinctions in quantity of extracted mobile compounds of heavy metals in the soil depending on a form of addition various connections of Cu and Zn are established. The smallest mobility of Cu and Zn at addition of heavy metal oxides is observed. It is established that Cu accumulates mainly in the fraction connected with organic matter; Zn accumulates in residual fraction and in the fraction connected with ferric oxide and manganese oxide by consecutive fractionation technique. [ABSTRACT FROM AUTHOR]

Potentially toxic elements (PTE) pollution has a pronounced negative effect on the soil and its components. The characteristics of soil organic matter and the activity of soil enzymes can serve as sensitive indicators of the degree of changes occurring in the soil. This study aims to assess the effect of long-term severe soil contamination with Zn and Cu on water-soluble organic matter (WSOM) and the associated changes in the biochemical activity of microorganisms. The total content of Zn and Cu in the studied soils varies greatly: Zn from 118 to 65,311 mg/kg, Cu from 52 to 437 mg/kg. The content of WSOM was determined using cold and hot extraction. It was revealed that the WSOM, extracted with cold water is a sensitive indicator reflecting the nature of the interaction of Zn and Cu with it. With an increase in the Cu and Zn content, the amount of WSOM extracted with cold water increases due to rise in the complex-bound metal compounds associated with it. The content of complex-bound compounds Zn in Spolic Technosols reaches 50% of the total metal content. It is shown that one of the biogeochemical mechanisms of microorganisms' adaptation to metal contamination is clearly manifested by the increase in the content of WSOM. The precipitation of metal carbonates develops in the soil which reduces the mobility and toxicity of PTE. Due to this mechanism, a decrease in the activity of dehydrogenases and urease was not prominent in all studied soils, despite the very high level of pollution and the transformation of organic matter. The study of the relationship of PTE with the most easily transformed part of WSOM and the activity of soil enzymes is of great importance for an objective assessment of possible environmental risks. • The content of water-soluble organic matter is one of the indicators of long-term pollution with HMs. • The content of cold water extracted soil organic matter increases in polluted soils. • Long-term pollution did not affect the total organic carbon content. • Urease and dehydrogenase activity is closely related to carbonate content. • Precipitation of carbonates is a mechanism for adaptation to long-term HMs pollution. [ABSTRACT FROM AUTHOR]