Background: Espresso coffee grounds constitute a residue which is produced daily in considerable amounts, and is often pointed out as being potentially interesting for plant nutrition. Two experiments (incubations and field experiments) were carried out to evaluate the potential nitrogen (N) and phosphorus (P) supply for carrot (Daucus carota L.), spinach (Spinacea oleracea L.) and lettuce (Lactuca sativa L.) nutrition.
Results: Immobilisation of nitrogen and phosphorus was detected in all the incubations and, in the field experiments, germination and yield growth were decreased by the presence of espresso coffee grounds, in general for all the species studied.
Conclusion: The study showed an inhibition of N and P mineralisation and a reduction of plant germination and growth. Further research is required to determine whether this is related to the immobilising capacity of the residue or possibly due to the presence of caffeine.
Keywords: espresso coffee grounds; germination; incubations; nitrogen mineralisation; vegetables.
© 2015 Society of Chemical Industry.