RESEARCHES OF THE INFLUENCE OF NITRATE CONTENTS ON MAIN MORPHOLOGICAL TRAITS OF MAIZE PLANTS

Nitrogen is an important element required for plant growth and development. It is a key component in many biological compounds that play a major role in photosynthetic activity and crop yield capacity. Variation in nitrogen availability can affect plant development and productivity in maize. One of the ways of soil pollution through agricultural technology is over-fertilization and, in particular, the administration of high doses of nitrogen fertilizers. Excess of nitrogen fertilizers, as well as their empirical application, have negative effects on harvest quality. Excessive use of fertilizers with nitrogen, produces of ion nitric accumulation in the soil (temporary) and in plants, which disturbs the balance of photosynthesis, causes the appearance of necrosis and burns on leaves, severe intoxication and even death by asphyxiation phenomena and cyanosis at ruminants, children and old people. The main aim of this study was to determine the effect of different nitrogen levels and different type of fertilizers on nitrates levels in maize leaves and on morphological traits of maize plants. Field experiments were conducted in two growing seasons (2017 and 2018) with five nitrogen levels (80 kg/ha, 120 kg/ha, 160 kg/ha, 200 kg/ha and 240 kg/ha) and two type of nitrogen fertilizers (ammonium nitrate and urea).