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.