Wind Erosion Contribution to Pesticide Transport

Although 40% of Hungary's territory is very sensitive to deflation, few studies have been conducted on wind-eroded sediment as an environmental pathway for pesticide transport.

Three experiment were conducted on loam soil and an other in sandy soil near Szeged (Hungarian Great Plain) in 2017, 2018, 2019, to examine wind-eroded sediment as a transport mechanism for two surface-applied pesticides [chlorpyrifos and pendimethalin].

For the experiments we used a portable 12 m long wind tunnel and a Wet Active Sediment Trap (WAST). WAST is a horizontal, isokinetic active wet trap that is patterned at different heights to collect the suspended soil fractions. Trap inlets are 5-10 cm, 20-25 cm, 50-55 cm high. Rolling soil samples (sediments) were also collected in a recessed tray at the end of the wind tunnel with a clean brush.

Before the experiment, a part of the sample area was treated with chlorpyrifos (2l/ha) and pendimethalin (5l/ha). A control area was also selected. Samples were taken before and after the wind event at 3 different places in the wind tunnel.

In the laboratory we analyzed the topsoil samples (pH (H₂O), CaCO₃ (%), Arany yarn test, OM %, total salt content (%), humidity (%), pesticide contents) and the collected sediments (chlorpyrifos, pendimethalin concentrations) according to hungarian standard procedures.

We calculated the enrichment ratios (ER) of concentrations in the rolling and suspended samples.

Our measurements showed that the enrichment of chlorpyrifos and pendimethalin can be clearly indicated in the sediments. The mean value of chlorpyrifos ER in 2017 is 3,4. In 2018 the mean value of chlorpyrifos ER is 2,9 and of pendimethalin ER is 13,7. Pendimethalin ER is much higher in the rolled fraction than chlorpyrifos. Measurements of 2019 showed us that the analyzed pesticides were enriched in the rolling soil fraction. There were no pesticides enrichment in the suspended fraction.

 

The research was funded by the ‘Thematic Network for the Sustainable Use of Resources – RING2017’ project (program code: EFOP-3.6.2-16-201700010) and by the support of OTKA 1K 116981, "In situ wind channel experimentation based on in situ wind channel experiments on different soil types, on site and off site effects" and supported by the ÚNKP-19-3 New National Excellence Program of the Ministry for Innovation and Technology”.