Abstract: The subject matter of the present invention is a composition for inhibiting urease and nitrification, which may be in liquid or solid form and which comprises at least one compound for inhibiting urease, of phosphoramide type, combined with an essential oil of Allium preferably originating from Allium sativum. This composition may be used in combination with a urea-based fertilizer for the manufacture of fertilizing compositions.

Abstract: The subject matter of the present invention is a composition for inhibiting urease and nitrification, which may be in liquid or solid form and which comprises at least one compound for inhibiting urease, of phosphoramide type, combined with an essential oil of Allium preferably originating from Allium sativum. This composition may be used in combination with a urea-based fertilizer for the manufacture of fertilizing compositions.

Abstract: It consists of using a precursor compound of cyclic AMP, or an inhibitor compound of the enzymes of the Phosphodiesterases family, or a stimulating compound of the enzymes of the Adenyl-Cyclase family, or an agonist compound of the &bgr;-adrenergic receptors to which arachidonic acid or a prostaglandin is added. The composition object of the invention can be presented mixed with mineral fertilizers (such as amonic nitrate, monopotassium phosphate, etc.), with phytoregulators (such as cytoquinines, auxines, giberelines, polyamines, n-ethanolamines, sugars . . . ) or with any type of phytosanitary product (such as fungicides, herbicides etc.). The composition object of the invention can be formulated with tensoactive agents (such as Tween 80), moistening agents etc. The composition object of the invention can be applied to any species of plant and at any point in its life cycle.