Effect of controlled release formulations of diuron and alachlor herbicides on the biochemical activity of agricultural soils

Abstract

The use of pesticides in agriculture is essential because it reduces the economic losses caused by pests, improving crop yields. In spite of the growing number of studies concerning the development and application of controlled release formulations (CRFs) of pesticides in agricultural soils, there are no studies about the effects of such formulations on the biochemical properties. In this paper the dissipation of diuron and alachlor in three agricultural soils for 127days, applied either as commercial or CRFs, was determined as well as their concomitant effects on soil biochemical properties. Dehydrogenase, urease, β-glucosidase and phosphatase activities were measured thought the experimental period. The application of alachlor as CRF increases its half-life time in soils, whereas no differences were noticed between diuron formulations due to its slower degradation, which takes longer than its release from the CRF. At the end of the incubation period, the enzymatic activities were the same after the use of diuron either as commercial or CRF, recovering the soil previous status. For alachlor formulations, no differences in enzymatic activities were again observed between both formulations, but their levels in soils were enhanced. Therefore, the use of these CRFs does not adversely affect the soil biochemical properties.

Constructing sustained‐release herbicide formulations based on poly‐3‐hydroxybutyrate and natural materials as a degradable matrix

“…Other data, however, suggested that slow‐release formulations of herbicides loaded into carriers, unlike their free forms, did not inhibit the growth of soil microbiota and stimulated enzymatic activity of soil. For instance, application of controlled‐release formulations of diuron and alachlor, loaded into phosphatidylcholine‐montmorillonite complex, enhanced dehydrogenase, phosphatase, and β‐glucosidase activity in soil . The addition of compost or sewage sludge to soil reduced the negative effects of herbicides on soil microorganisms …”

“…For instance, application of controlled-release formulations of diuron and alachlor, loaded into phosphatidylcholine-montmorillonite complex, enhanced dehydrogenase, phosphatase, and -glucosidase activity in soil. 69 The addition of compost or sewage sludge to soil reduced the negative effects of herbicides on soil microorganisms. 70 The effects of the experimental herbicide formulations on soil microflora were studied.…”

Non-target effects on soil microbial parameters of the synthetic pesticide carbendazim with the biopesticides cantharidin and norcantharidin

“…Application of pesticides is therefore a common and critical method to improve crop yield 3–5 . Of the tremendous amount of pesticides used, more than 99.7% persist and are accumulated in the environment 6–8 , undergoing various physicochemical catabolism and biodegradation processes which are closely associated with the composition and activity of soil microbial community 9–11 . Soil microorganisms have key functions in many vital soil processes, such as organic matter decomposition and nutrient cycling, and are responsible to a great extent for the function of soil ecosystems 12 .…”

2,4-Dichlorophenoxyacetic acid adsorption on montmorillonite organoclay for controlled release applications

“…The use of modified clays in CRS for agriculture applications is widely reported in the literature [8][9][10]. Rytwo and Moshe [8] reported the use of montmorillonite modified with quaternary ammonium salts, such octadecyltrimethylammonium (ODTMA) and berberine, and other modifiers for the controlled release of allyl isothiocyanate (AITC), mustard oil major component used in the agriculture as fumigant in the control of insects.…”

“…The montmorillonite modification increased by at least 60% the time release of AITC. Tejada et al [9] studied the use of Na-montmorillonite modified with phosphatidylcholine (PC) for controlled release of the herbicides diuron and alachlor in soils. The dissipated amount of the herbicides in the soils using the PC-clay formulations was lower when compared with the direct herbicide application, mainly for alachlor in the first 16 days of incubation.…”