Soil solarization based on natural soil moisture: a practical approach for reducing the seed bank of invasive plants in wetlands

Abstract

Soil solarization is a well-established method to disinfect soil for efficient weed control. However, the feasibility of applying this method in the restoration of invaded natural habitats is unclear. This is because soil moisture is necessary for the success of solarization, but pre-irrigation in natural ecosystems is often not applicable, or demands high labor investment, making it unsuitable for use in restoration. The present study was based on the idea that the relatively high soil moisture in wetlands might obviate the need for pre-irrigation, rendering this method much more applicable in natural habitats. We examined the efficacy of soil solarization using natural soil moisture to control the seed bank of the invasive plant, Acacia saligna, in a wetland, using large-scale experimental plots (0.38 ha each). An old, dense A. saligna grove was cut down and the roots were removed by a bulldozer. The plot was mulched with a transparent polyethylene sheet in early July and left on the soil for 14 weeks. Soil solarization significantly reduced the viability of seeds of A. saligna that had been experimentally buried. Additionally, viability of seeds in the natural seed bank was reduced, and seedling emergence was close to zero. Exposing seeds to soil temperature and soil moisture levels equivalent to those obtained during field soil solarization under controlled conditions significantly increased the release from dormancy of the seeds, suggesting that release from dormancy during the early stage of solarization is a critical stage leading to seed weakening or mortality in the soil. Soil solarization also decreased the cover and abundance of the natural vegetation; therefore, active revegetation is required to restore the natural vegetation and to conserve endangered and endemic species.

Performance of cultural and mechanical practices on weed-control efficiency, productivity and economics of Indian mustard (Brassica juncea) under organic production

“…At 40 DAS, total weed density was found lowest under mechanical weeding at 25 DAS + HW at 50 DAS and was statistically identical with 2 HW at 25 and 50 DAS, followed by soil solarization with 25 μm transparent polythene sheet + HW at 40 DAS, and the highest under application of Indian mustard oil cake @ 5 t/ha + HW at 40 DAS. Soil solarization is a hydrothermal method of weed management in which solar energy of sunlight is trapped under the transparent polyethylene sheet (Cohen et al, 2019). The solar energy increases the temperature of the soil, and weed seed loses its viability.…”

Sunlight can have a stronger influence than air temperature on soil solarisation: observational evidence from Australia

“…Specifically, practitioners do have control over the timing of solarisation, which determines the magnitude of both temperature and solar radiationthe drivers responsible for raising the temperature of solarised soil. In contrast, practitioners typically do not have the option to artificially water or till the soil due to infrastructure and equipment limitations (Cohen et al 2019).…”

Essential Oil in the Management of the Seed Bank of Infestant Plants

“…Solarization in turn has been employed by researchers such as Cohen et al (2019), who affirm the effectiveness of solarization in reducing the seed bank of various invasive trees, including Pereskia aculeata and Leucaena leucocephala. According to Fragoso et al (2016), it was observed in the field that soil solarization promoted greater control over (Megathyrsus maximus) colonião grass compared to (Cyperus rotundus) tiririca, however being efficient on the species studied.…”