Utilization of Spent Coffee Grounds as Media for Stone Pine (Pinus pinea) Seedlings

Abstract

The present study was aimed at determining the influence of adding different amounts of spent coffee grounds (SCG) on germination percentage (GP) and mean germination time (MGT), seedling characteristics, and seedling biomass of different components of containerized 1 + 0 stone pine seedlings. Six different media were prepared including 100% conventional media, 100% sand, 10% SCG + 90% sand, 20% SCG + 80% sand, 30% SCG + 70%, sand and 100% SCG. While GP is 90% in the media where the SCG ratio is 10%, GP values decrease to 50% as the SCG ratio increases. The greatest seedling height values were found in conventional media (14.4 cm), followed by the seedlings in 100% sand with 11.4 cm and 20% SCG + 80% sand with 11.1 cm. The highest root collar diameter was found in 20% SCG + 80% sand with 3.9 mm. The highest root/shoot ratio (0.7) was obtained in 10% SCG + 90% sand. Total seedling biomass was the greatest in conventional media (2.1 g). As SCG increased in the media, N, K, Mg, and P concentrations increased, and Ca concentration and C/N ratio decreased in all seedling components (needle, main root, lateral root, and stem). Results point to the possibility of using a small amount of SCG to alter seed germination, seedling characteristics, and nutrient uptake for production of containerized stone pine seedlings.

Hydrochars Derived from Spent Coffee Grounds as Zn Bio-Chelates for Agronomic Biofortification

“…Limited plant growth may mainly be attributed to the SCG composition of caffeine, polyphenols, and tannins [16,22], which have been identified to be not only phytotoxic but also ecotoxic [37]. Several authors have reported toxicity effects with different doses of SCG in lettuce (2.5, 10%) [19] and stone pine seedlings, which are also rich in polyphenols and tannins, at 10, 20, 30, and 100% [38]. In contrast, some authors describe enhanced dry weight when plants are found in sandy low mineral soil [39,40].…”

Scientometric Overview of Coffee By-Products and Their Applications

“…According to the literature, fertilizing with CH and SCG is a good cropping practice to contribute to the sustainability of agriculture [95,96]. In the work of Zoca et al, CP, CH, and composted CH were evaluated as fertilizers, since they contain the important mineral potassium (K) [97].…”

“…The use of CH and their biochar as soil amendments could reduce fertilization costs and prevent environmental degradation by recycling the nutrients that would be lost by leaching or runoff from the stored residue for prolonged times [97]. Moreover, SCG have been used to store stone pine seedlings, and it was found that mixtures of 10-20% SCG and sand increased the germination time and enhanced the characteristics of the seedlings by supplementing K, N, Mg, and P [95]. Similarly, water extracts from SCG and tea leaves have been used as the primer agents (growth inducers) of pepper [96].…”

Destinação sustentável de borra de café com uso da compostagem

“…Além disso, o resíduo do pó de café é rico em compostos orgânicos, a exemplo de ácidos graxos, lignina, celulose, hemicelulose, entre outros, fazendo parte também da composição desse resíduo, alguns minerais, tais como potássio, fósforo e magnésio, com predominância do potássio, os quais podem contribuir para a nutrição das plantas. (CALISKAN et al, 2020).…”