Stationary soil steaming to combat invasive plant species for soil relocation

Zahra Bitarafan,Lars Olav Brandsæter,Wiktoria Kaczmarek-Derda,Inger Sundheim Fløistad

doi:10.1017/inp.2021.25

Abstract

AbstractEradication of alien invasive species in the soil with steam as an alternative to chemical fumigation may allow contaminated soil to be reused. We have investigated steam disinfestation of soil to combat invasive plant species in three experiments including different temperatures and exposure durations using a prototype stationary soil-steaming device. The experiments included effects on seed germination of bigleaf lupine (Lupinus polyphyllusLindl.), ornamental jewelweed (Impatiens glanduliferaRoyle), and wild oat (Avena fatuaL.; one population from Poland and one from Norway), as well as effects on sprouting rhizome fragments of Canada goldenrod (Solidago canadensisL.) and Bohemian knotweed (ReynoutriaxbohemicaChrtek & Chrtková). In Experiment 1, we tested four different soil temperatures of 64, 75, 79, and 98 C with an exposure duration of 90 s. In Experiments 2 and 3, we tested exposure durations of 30, 90, and 180 s and 90, 180, and 540 s, respectively, at 98 C. Seed pretreatment of 14 d cooling forL. polyphyllusandI. glandulifera, no seed pretreatment and 12-h moistening forA. fatuapopulations, and 5- and 10-cm cutting size forR. xbohemicawere applied. Our results showed germination/sprouting was inhibited at 75 C forI.glandulifera(for 90 s) and 98 C for the other species; however, longer exposure duration was needed forL.polyphyllus. While 30 s at 98 C was enough to killA.fatuaseeds andS.canadensisandR. xbohemicarhizome fragments, 180-s exposure duration was needed to killL.polyphyllusseeds. The results showed promising control levels of invasive plant propagules in contaminated soil by steaming, supporting the steam treatment method as a potential way of disinfecting soil to prevent dispersal of invasive species.

Highlights

Invasive species may modify soils they are occupying in ways that increase their own fitness relative to native species
We have investigated steam disinfestation of soil to combat invasive plant species in three experiments including different temperatures and exposure durations using a prototype stationary soil-steaming device
Our results showed germination/sprouting was inhibited at 75 C for I. glandulifera and 98 C for the other species; longer exposure duration was needed for L. polyphyllus

Summary

Introduction

Invasive species may modify soils they are occupying in ways that increase their own fitness relative to native species. Noxious weeds develop characteristics such as rapid growth rates, high seed production, and extended growing periods, all of which provide them with an advantage over native plants in occupying the soil (Sheley et al 1996). Long-distance dispersal of plant propagules determines large-scale phenomena of greatest conservation concern, such as the spread of invasive plants (Trakhtenbrot et al 2005). The most effective method for managing noxious weeds is to prevent their invasion using a combination of methods aimed at limiting encroachment (Sheley et al 1996). Limiting weed seed dispersal, containing neighboring weed infestations, minimizing soil disturbances, detecting and eradicating weed introductions early, and establishing competitive grasses following proper grass management have been proposed by Sheley et al (1996) to prevent noxious weeds from spreading. The process of moving soil should be done only when the soil has been inspected and verified to be free of serious diseases and pests

Objectives

Methods

Results