Nitrogen and water use efficiency of maize in long-term field experiment

The aim of the study was to characterize the productivity of maize for grain, fertilized with nitrogen rates 50- 250 kg N·ha-1 depending on its nitrogen and water use efficiency. It was found, that grain yields of the crop raised statistically significant up to 8.03 t·ha-1 under 150 kg N·ha-1 . Such a dose guaranteed: nitrogen uptake 182 kg N·ha-1 , nitrogen use efficiency 121%, nitrogen surplus 32 kg N·ha-1 , water use efficiency 14,5 kg·ha-1 ·mm-1 . Increasing nitrogen doses over the years was not justified because maize productivity was limited by water availability under higher nitrogen rates.

Maize grown for grain is the third largest cereal crop species in the world. Due to the fact, that both nitrogen uptake and NUE are largely influenced by water availability, the efficiency of nitrogen utilization is considered together with the water use efficiency (WUE) (Li et al., 2019).