Nitrogen use efficiency and performance of maize (Zea mays L.) cultivars as influenced by calcium carbide and inorganic nitrogen application rates in a derived savanna

Field experiments were conducted to investigate nitrogen use efficiency and performance of maize (Zea mays L.) cultivars as influenced by calcium carbide (CaC2) and nitrogen (N) rates in a derived Savanna (2016 and 2017). Maize cultivars {SUWAN-I [open pollinated variety (OPV)] and OBA SUPER II (hybrid)}, rates of N (0, 60 and 90 kg ha(-1)) and CaC2 (0, 30 and 60 kg ha(-1)), were arranged in split-split plot respectively, fitted into a randomized complete block design in three replicates. N Partial factor productivity (PFPN), Agronomic Use Efficiency (both years) and Apparent recovery of N (2017) increased in the order 60 > 90 > 0 kg N ha(-1), except N Internal use efficiency which was in the order 0 > 60 > 90 kg N ha(-1) (2017). Grain yield increased with increasing rates of N in both years. OBA SUPER-II had significantly higher grain yield than SUWAN-I (2017). Similar pattern was observed on number of grains per cob, dry cob weight, PFPN and plant height (2017). Conversely in 2016, grain, total and shoot N uptakes were significantly higher in SUWAN-I than OBA SUPER-II. Increasing application of CaC2 increased grain N uptake and number of grains per cob. Number of leaves and stem girth increased in the order of 60 > 0 > 30 kg CaC2 ha(-1). Increased grain yield with N rates could be associated with NHI and N use efficiency. These evidences suggested that hybrid maize performed better than OPV in a derived Savanna.