Risks for surface runoff and leaching of fungicides from golf greens varying in rootzone composition and amount of thatch

Summary

This project examines leaching and surface runoff of five fungicides and their metabolites after prophylactic application against snow mould in autumn. Field work was conducted in winter 2016-17 and 2017-18 at NIBIO Landvik, Norway. The plots had 5% slope and creeping bentgrass turf. The trial had four blocks and two factors, each with two levels:

Factor 1: Type of organic amendment to the sand-based (USGA) rootzone:

Factor 2: Turf age/thatch thickness

1.     Sphagnum peat, ignition loss 1.1%, pH 5.5

A.      Green sown in May 2016

2.     Garden compost, ignition loss 1.0%, pH 6.5

B.      Green established in May 2016 using sand-based sod, thatch layer 20 mm

In both years, Delaro SC 325 (prothioconazole + trifloxystrobin) and Signum (boscalid + pyraclostrobin) were sprayed in mid/late October and Medallion TL (fludioxonil) was sprayed in early/mid-November, followed by collection of leachate and runoff until the last snow or ice melt in late March/early April.  

In winter 2016-17, the mostly unfrozen greens had very high infiltration rates: 91% of 601 mm precipitation that fell from first fungicide application to the last sampling was collected as drainage water and only 3% as runoff. Winter 2018-19 had 975 mm precipitation and freeze/thaw cycles on frozen greens resulted in ice cover. In that winter,53 and 32 % of pre-cipitation was retained as leachate and runoff, respectively, while 9% was removed as snow.

In both winters, fungicide detections in drainage water were mostly rare; the Norwegian Environmental Safety Concentration (NESC) was exceeded slightly only for the prothioco-nazole metabolite desthio. In surface water, the NESC for all fungicides and/or their meta-bolites were often exceeded 10-100-fold, especially in 2017-18. The highest concentrations coincided with high rainfall intensity in the week after application but also when the green surface re-exposed due to melting episodes. Concentrations in runoff were usually higher on greens established from sod than from seed.  This shows  the importance of avoiding surface runoff after fungicide application. Infiltration rates must be upheld and wide buffer strips to open water maintained when spraying fungicides. 

 

Contact
Trygve Aamlid

Trygve S. Aamlid, Norwegian Institute for Bioeconomy (NIBIO), Department for Urban Greening and Environmental Technology, Turfgrass Research Group, Landvik, Reddalsveien 215, 4886 Grimstad, Norway. Phone: +47 90 52 83 78. E-mail: trygve.aamlid@nibio.no

FACTS
Category: Disease control
Status: Ongoing
Project period: 2016 -2018

Fundings (kSEK)

 

kSEK

 

2016

2017

2018

2019

Sum

STERF

303

294

86

75

758

Other sources 518 422 259 94 1292

TOTAL FUNDING

821

716


345

169

2052

 

Project objectives

Main objective: To minimise fungicide losses from golf courses.

Subgoals:

  • To determine sorption coefficients and thus the risk of leaching of prothioconazole, trifloxystrobin, fludioxonil, boscalid, pyraclostrobin and their metabolites
  • To determine the effect of organic matter type (peat or compost) and turf age/thatch accumulation on the risk of leaching and surface runoff of these fungicides and their metabolites
  • To provide data for modelling leaching and runoff of fungicides from golf greens
  • To publish the results in ‘Journal of Environmental Technology’ or a similar peer-reviewed journal and to disseminate the findings to the environmental authorities and the golf industry in the Nordic countries and Germany.

Project participants

Trygve S. Aamlid

Head of Research

Norwegian Institute for Bioeconomy (NIBIO), Department for Urban Greening and Environmental Technology, Turfgrass Research Group, Landvik, Reddalsveien 215, 4886 Grimstad, Norway.

+47 90 52 83 78

+47 90528378

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