Excessive nitrogen application under moderate soil water deficit decreases photosynthesis, respiration, carbon gain and water use efficiency of maize.

The impact of water stress and nitrogen (N) nutrition on leaf respiration (R), carbon balance and water use efficiency (WUE) remains largely elusive. Therefore, the objective of the present study was to investigate the effect of soil water and N stresses on growth, physiological responses, leaf structure, carbon gain and WUE of maize. The plants were subjected to different soil water and N regimes to maturity.