Nitrogen, the most abundant element in the atmosphere, is indispensable for life. It is essential for the synthesis of organic molecules such as nucleic acids, ATP, structural proteins, and chlorophyll. In its cycle, nitrogen goes through several processes: mineralization (transformation of organic N into inorganic), ammonification (conversion of organic nitrogenous compounds into NH4+), nitrification (NH oxidation4+ a NO3–) and denitrification (reduction of nitrate to gaseous forms of nitrogen). Nitrogen deficiency limits plant growth, causing chlorosis and atrophy in stems, leaves and roots.