EVALUATING THE EFFECTIVENESS OF FOLIAR FEEDINGS WITH NITROGEN-CONTAINING FERTILIZERS AS EXEMPLIFIED BY MAIZE

The studies were aimed at determining the methods for the effective use of nitrogen fertilizers on maize. In the course of the studies, the authors put forward a hypothesis that the foliar use of nitrogen-containing agrochemicals can significantly increase the productivity of maize. They assessed the economic efficiency of foliar application of conventional nitrogen fertilizer (urea) and new nitrogen-containing agrochemicals to maize hybrids of different ripeness groups. The study purpose was to make a comparative effectiveness assessment of the foliar feeding of maize hybrids belonging to different ripening groups with urea as well as organic fertilizer Batr 40 Azot and antistressant stimulant Vuksal Aminoplant. The studies were conducted on the experimental field of the All Russian Research Institute of Maize located at a distance of 3 km from the Pyatigorskiy settlement in the Prdgorniy District of the Stavropol Krai, at an altitude of 541 m above sea level, 44° north latitude, 43° east longitudes in a zone of sufficient moisture. The effect of two factors was studied in the field experiment: factor A – maize hybrids, factor B – foliar fertilization. The varieties used in the study of factor A included early ripening maize hybrid Mashuk 185 MV (FAO 180), mid-early ripening maize hybrid Mashuk 220 MB (FAO 220), and mid-ripening maize hybrid Mashuk 355 MB (FAO 350). The following options were studied Ь as factor B: without fertilizers; foliar application of Batr 40 Azot (3.0 l/ha), Vuksal Aminoplant (1.5 l/ha), and urea (N10). It was found that in the zone of sufficient moisture on the ordinary carbonate thick heavy loamy chernozem of the Stavropol Krai foliar application of nitrogencontaining fertilizers had a positive effect on the growth and productivity of maize hybrids. On average for 2018–2020, foliar feeding of plants in the phase of 7–8 leaves with agrochemicals Batr 40 Azot (3.0 l/ha) and Vuksal Aminoplant (1.5 l/ha) increased the yield of green mass of hybrid Mashuk 185 MV by 3.63–3.97 t/ha (11–12%); the yield of green mass of the hybrid Mashuk 220 MV increased by 6.85–7.46 t/ha (24–26%); the yield of green mass of the hybrid Mashuk 355 MV increased by 4.63–5.05 t/ha (14–16%). The grain yield of the hybrid Mashuk 185 MV increased by 0.21–0.47 t/ha (3–8%); the grain yield of the hybrid Mashuk 220 MV increased by 0.37–0.49 t/ha (7–9%); the grain yield of the hybrid Mashuk 355 MV increased by 0.30–0.33 t/ha (5–6%). Fertilizing maize hybrids with agrochemicals Batr 40 Azot (3.0 l/ha) and Vuksal Aminoplant (1.5 l/ha) at a dose of N10 provided higher green mass and grain yield as compared to urea (carbamide). The mid-early ripening hybrid Mashuk 220 MB was most responsive to foliar application of nitrogen-containing fertilizers. The costs of using fertilizers Batr 40 Nitrogen (3.0 l/ha), Vuksal Aminoplant (1.5 l/ha), and urea (N10) for foliar dressing were compensated by the income received. The highest average payback of 1 ruble spent on maize hybrids was noted for foliar feeding of plants with the fertilizer Batr 40 Nitrogen at a dose of 3.0 l/ha (1.31 rubles of income) and Vuksal Aminoplant at a dose of 1.5 l/ha (1.11 rubles of income).