Possibly Invasive New Bioenergy Crop Silphium perfoliatum: Growth and Reproduction Are Promoted in Moist Soil

Abstract

The cup plant (Silphium perfoliatum) is a new and promising bioenergy crop in Central Europe. Native to North America, its cultivation in Europe has increased in recent years. Cup plant is said to be highly productive, reproductive, and strongly competitive, which could encourage invasiveness. Spontaneous spread has already been documented. Knowledge about habitat requirements is low but necessary, in order to predict sites where it could spontaneously colonize. The present experimental study investigates the growth and reproductive potential of cup plant depending on soil moisture, given as water table distance (WTD). In moist soil conditions, the growth and reproductive potential of cup plant were the highest, with about 3 m plant height, 1.5 kg dry biomass, and about 350 capitula per plant in the second growing season. These parameters decreased significantly in wetter, and especially in drier conditions. The number of shoots per plant and number of fruits per capitulum were independent of WTD. In conclusion, valuable moist ecosystems could be at risk for becoming invaded by cup plant. Hence, fields for cultivating cup plant should be carefully chosen, and distances to such ecosystems should be held. Spontaneous colonization by cup plant must be strictly monitored in order to be able to combat this species where necessary.

Biomass partitioning and nutrient fluxes in Silphium perfoliatum and silage maize cropping systems

“…Our results are in line with studies (Ende et al 2021;Schoo et al 2017a) that have refuted the initial assumption that the cup plant suits very well for cultivation under drier soil conditions (Bauböck et al 2014;Pan et al 2011;Sokolov and Gritsak 1972). Although Schoo et al (2017b) have shown that cup plant has not a higher water capture capacity than maize, the enduring rooting system in the subsoil may be favorable.…”

Spreading of the cup plant (Silphium perfoliatum) in northern Bavaria (Germany) from bioenergy crops

“…This was possibly because all the investigated sites had an average EIV soil moisture. But the preference of cup plants for moist sites was also confirmed by experimental studies in Germany by Ende et al (2021), where it showed higher biomass and reproductive potential under moist soil conditions. Therefore, special attention must be paid to moist habitats because they are often valuable for nature conservation and could be colonized by the cup plant (Ende et al 2021).…”

“…In fact, losing of crop and thus of fruits from the trailer is quite possible and must be kept in mind regarding the prevention of cup plant spread. A dispersal of the fruits and of root parts via water would also be conceivable and was suspected by Ende et al (2021) and Vladimirov (2021). Altogether, we suspect a certain dispersal potential of cup plant -even over longer distances.…”

“…The cup plant is a perennial, yellow-flowering hemicryptophyte of the Asteraceae family and is native to the prairies of eastern North America (Stanford 1990;Jäger 2017). It grows 2-4 m high and can develop several hundred flower heads, each with 20-30 fruits (Stanford 1990;Dauber et al 2016;Ende et al 2021). The flowering period is from July on, fruits ripen from August onwards and then drop out (Jabłoński and Kołtowski 2005;Penskar and Crispin 2010;Wrobel et al 2013;Jäger 2017).…”

The perennial biogas crops cup plant (Silphium perfoliatum L.) and field grass pose better autumn and overwintering habitats for arthropods than silage maize (Zea mays L.)

“…It was reported to have a dry matter yield per hectare that is about 20% lower, and a methane yield that is about 35% lower than that of silage maize (Gansberger et al, 2015). On soils with a high water supply, the cup plant has the potential to achieve higher biomass yields than usual (Ende et al, 2021; Schoo, Schroetter, et al, 2017), but methane yields are still generally lower than in silage maize (Ruf & Emmerling, 2022). Cup plant was found to improve the soil fertility and its greenhouse gas balance due to carbon sequestration and enhanced soil formation (Feldwisch, 2011; Franzaring et al, 2015).…”