The field of the invention is that of products for enriching agricultural soils. The problem posed consists in preparing such a product which has at the same time an advantageous yield and plastic properties and with a rigidity which makes it possible to shape it during manufacture. This objective is achieved using a solid compound for enriching agricultural soils, characterised in that it consists, on the one hand, of a compost of animal and/or plant origin and, on the other hand, of a biodegradable binder for stiffening the compound, the compound being preferentially based on earthworm casts. The invention preferentially finds an application in the production of biodegradable flowerpots and of standardised fertiliser charges (fillers).
