Leaching and surface runoff after fall application of fungicides on putting greens

Abstract

Many greenkeepers and authorities are concerned about the environmental risks resulting from pesticide use on golf courses. We studied leaching and surface runoff of fungicides and metabolites for two winter seasons after fall application of boscalid, pyraclostrobin, prothioconazole, trifloxystrobin, and fludioxonil in field lysimeters at NIBIO Landvik, Norway. The applications were made on creeping bentgrass greens (5% slope) that had been established from seed or sod (26-mm mat) on USGAspecification. root zones amended with Sphagnum peat or garden compost, both with 0.3-0.4% organic carbon in the root zone. The proportions of the winter precipitation recovered as surface and drainage water varied from 3 and 91% in 2016-2017 to 33 and 55% in 2017-2018 due to differences in soil freezing, rainfall intensity, and snow and ice cover. Detections of fungicides and their metabolites in drainage water were mostly within the environmental risk limits (ERLs) for aquatic organisms. In contrast, concentrations in surface runoff exceeded ERLs by up to 1,000 times. Greens established from sod usually had higher fungicide losses in surface runoff but lower losses in drainage water than greens established from seed. Presumably because of higher microbial activity and a higher pH that made prothioconazole-desthio more polar, fungicide and metabolite losses in drainage water were usually higher from greens containing compost that from greens containing peat. Leaching of fungicides and metabolites occurred even from frozen greens. The results are discussed in a practical context aiming for reduced environmental risks from spraying fungicides against turfgrass winter diseases.

Fate of Tebuconazole in Polish Mineral Soils – Results of Simulations with FOCUS PELMO

“…The Danish Pesticide Leaching Assessment Program indicated that the highest tebuconazole concentrations in ground water at 1 m depth (range of 0.05-2 μg/L) were detected in the soils with texture of sandy loam, in which the preferential transport occurred [Rosenbom et al, 2015]. In the soils with texture of sand and loamy sand, in which the piston flow was dominant, detectable concentrations of the fungicide were detected only in a few samples, with maximum concentrationsof 0.01 μg/L.The concentrations of azole fungicides in drainage water determined in the lysimetric studies by Aamlid et al [2021] simulating pesticide leaching in golf courses (where they are frequently used)were also low -in the range of 0.003-0.015 μg/L. Thus, the results of our studies, which signalize that the existence of higher concentrations of tebuconazole in groundwater at 1 m depth is unlikely in the examined soils, is consistent with the results obtained by the above-mentioned authors.…”

Acute aquatic toxicity of two commonly used fungicides to midwestern amphibian larvae

“…Post-application surface water run-off from elds has been found to exceed recommended environmental risk limits set by the United States Environmental Protection Agency (USEPA) for the fungicide pyraclostrobin (Aamlid et al, 2021). A European study examining the detection and concentration of pesticides in sediment found that the fungicides fenpropimorph and propiconazole were the most commonly detected pesticides (Kronvang et al, 2003).…”

“…a commonly reported EEC of around 160 µg/L(McMahon et al, 2013), which is nearly four times the LC50 for the most resistant amphibians in our study. It is also important to note that these EECs do not account for concentration spikes that are observed in waters following application and storm events(Aamlid et al, 2021;Zubrod et al, 2019). More broadly, EEC and amphibian LC50 estimates for fungicides are similar in magnitude relative to estimates for other pesticides.…”