Effects of Different Doses of Nitrogen on Growth and Nitrogen Use Efficiency of Maize (Zea mays L.) in Berekum Municipality of Ghana

Abstract

Background: Adequate and balanced use of plant nutrients could increase crop performance and reduce adverse environmental effects. Farmers in Berekum have little information on the specific rate of nutrient, especially nitrogen application for hybrid and open pollinated maize varieties. Methods: A field experiment was carried out in Berekum Municipality of Ghana to determine the effects of different doses of N fertilizer (0, 90, 120 and 150 kg N ha-1) on growth and nitrogen use efficiency (NUE) of Pannar 12 (hybrid) and Omankwa (open-pollinated) maize varieties. The experiment was conducted in a factorial randomized block design and replicated thrice. Result: Experimental results revealed that incremental doses of nitrogen significantly impacted vegetative growth and NUE of maize. The studies indicated that the growth response in terms of plant height, number of leaves per plant and stem diameter of Omankwa was better than that of Pannar 12. It was found that in the main cropping period of 2019, the maximum NUE of 14.58 kg/kg was gained when Pannar 12 was grown with 150 kg N ha-1, while the highest NUE (15.91 kg/kg) was recorded when Omankwa was grown with 90 kg N ha-1. In the minor season of 2019, NUE was highest (13.54 kg/kg) when Pannar 12 was grown with 150 kg N ha-1, while application of 120 kg N ha-1 to Omankwa resulted in the highest NUE (10.85 kg/kg). The studies indicated that application of nitrogen at 90, 120 and 150 kg N ha-1 improved NUE in maize. However, NUE was optimized in Pannar 12 due to application of 150 kg N ha-1, while application of 90 kg N ha-1 was enough to optimize NUE in Omankwa.