Dynamics of the soil nitrogen content depending on the forms of nitrogen fertilizers when growing corn for grain

Abstract

Nitrogen is vital to corn as it plays a key role in promoting healthy plant growth, building essential proteins and greatly increasing productivity. Maize is very sensitive to this element, and adequate nitrogen availability is essential to achieve high yields, both in terms of biomass production and final grain production. Therefore, the studies of the effectiveness of using different forms of nitrogen fertilizers in corn cultivation are relevant. The study aim was to compare the effectiveness of different forms of nitrogen fertilizers and their effect on the soil nitrogen content when corn cultivation. Methods. Field experiments were carried out in 2023 in the conditions of the Forest-steppe of Ukraine using generally accepted agricultural techniques for soil cultivation and the application of nitrogen fertilizers (CAM- 32, urea, anhydrous ammonia). A study of the nitrogen content at depths of 0–20 cm, 20–40 cm, and 40–60 cm (IV plot – control, without fertilizer) was carried out in four experimental plots before and after fertilizer application. Results. It was established, the soil nitrogen content on average in all plots increased by 15.0% (138.6 mg/kg), 12.7% (122.3 mg/kg) and 11.1% (93, 6 mg/kg) in the soil layers to a depth of 0–20 cm, 20–40 cm, 40–60 cm, respectively, after the fertilizers’ application. The fertilizers’ application to plots I–III had different effects on the soil nitrogen content at different depths. The greatest impact was determined on the 1st plot when KAS-32 (200 kg/ha) was used, due to which the nitrogen content increased by 37.1, 36.5 and 17.4% in the soil layers, 0–20 cm, 20–40 cm deep, 40–60 cm, respectively. On the II plot, where urea (150 kg/ha) was applied, the smallest increase in the soil nitrogen content was obtained – 5.5–7.4%. In the III plot, after the anhydrous ammonia introduction (85 kg/ha), the maximum increase in the soil nitrogen occurred at a depth of 0–20 cm – by 20.5 mg/kg (17.2 %) and at a depth of 40–60 cm – by 17 mg/kg (21.1 %). Conclusions. According to the study results, CAM-32 was the most effective form of nitrogen fertilizers in terms of impact on the soil nitrogen content due to the presence of all three forms of nitrogen in the composition. A longer period of time (7–14 days) is required to enhance the effect of anhydrous ammonia and urea on the soil nitrogen content.