Silphium perfoliatum—A Herbaceous Crop with Increased Interest in Recent Years for Multi-Purpose Use

Abstract

Silphium perfoliatum is a perennial crop native to North America that has been the subject of increased scientific interest in recent years, especially in Europe. It is drought- and frost-resistant, which makes it suitable for cultivation in Europe on marginal lands that are not used for growing other crops. This review analyzed the distribution and purposes of the cultivation of Silphium perfoliatum worldwide, as well as its biomass yields and characteristics as a feedstock for biogas production and other purposes. A total of 121 scientific publications on Silphium perfoliatum were identified, with the highest number (20 papers) published in 2019. It was found that higher biomass yields can be obtained at higher precipitation levels, with the use of fertilizers and an adequate type of plantation. The mean dry matter yield of Silphium perfoliatum was 13.3 Mg ha−1 DM (dry matter), and it ranged from 2 to over 32 Mg ha−1 DM. In some countries, Silphium is used as a forage crop mainly due to its high crude protein content (from 4.9% to 15% DM), depending on the vegetation phase. Silphium perfoliatum is a promising perennial crop in terms of energy and other benefits for biodiversity, soil quality and applications in medicine and pharmacology.

Forest Dendromass as Energy Feedstock: Diversity of Properties and Composition Depending on Systematic Genus and Organ

“…compared to the values for deciduous wood. A quarter of the results for the branches overall were not higher than 19.31 MJ kg −1 d.m., and 3 4 of the results were not lower than 20.78 MJ kg −1 d.m. The highest branch HHV was noted for Pinus spp.…”

“…and 0.50 percentage points, respectively, compared to the values for deciduous wood). A quarter of the results for total wood were under 19.12 MJ kg −1 d.m., and 3 4 of the results were above 20.05 MJ kg −1 d.m. The highest wood HHV among the genera under study was found for Pseudotsuga spp.…”

“…In order to prevent these phenomena, they have to be replaced with renewable energy sources (RES), including biomass. An increase in the share of RES in the energy acquisition structure helps to stem the growth of greenhouse gas emissions into the atmosphere and to reduce the pollution caused by fossil fuel combustion [3]. Due to its widespread presence, easy accessibility, and neutrality with respect to CO 2 emissions, biomass combustion does not increase that gas concentration in the atmosphere.…”

“…Currently, various biomass sources are sought that would be acceptable for use and suitable for commonly applied conversion technologies [3]. However, to use biomass as an energy feedstock, it is necessary to know its energy equivalent [10], which ranges from 17 to 21 MJ kg −1 (higher heating value-HHV) for dry wood, which makes wood a competitor for fossil fuels [11].…”

Ecological Intensification of Food Production by Integrating Forages

“…Although these forbs are coarse with stiff stalks and resinous, often hirsute leaves, early naturalists also noted that cattle often feed on silphium plants first when introduced to new prairie pastures [193]. Since that time, the largest, fastest-growing species, Silphium perfoliatum L. (cup plant) was adopted in central and northern Europe as a forage with dry matter yields ranging from 2-32 Mg ha −1 and crude protein content of 4.9-15% [194]. The forage value of this species has also been appreciated in Chile because it remains productive during the dry season when other (presumably more shallowly rooted) species are dormant or stressed [195].…”