Nitrogen (N)

Nitrogen is an essential macronutrient responsible for the growth of leaves and stems, as well as the development of the entire above-ground portion of the plant. Tomatoes absorb it primarily in two forms: nitrate (NO₃⁻) and ammonium (NH₄⁺). In gardening practice, it is preferable to fertilize with a predominance of the nitrate form, which is safer for the root system and promotes more balanced growth. Excess nitrogen causes lush leaf growth at the expense of flowering and fruiting, delays ripening, and increases the plants’ susceptibility to certain diseases. Conversely, a nitrogen deficiency manifests as pale green leaves, stunted growth, and small fruits. The best results are achieved by supplying nitrogen regularly in small doses, tailored to the tomato’s stage of development.