Effects of different nitrogen fertilizers on the yield, water- and nitrogen-use efficiencies of drip-fertigated wheat and maize in the North China Plain

Abstract Fertigated areas of wheat and maize in the North China Plain (NCP) have grown rapidly during recent years, but little information is available on the effects of different nitrogen (N) fertilizers applied through drip fertigation on wheat and maize. A field experiment was conducted in the NCP during 2012−2016 to evaluate the effects of urea, ammonium nitrate, ammonium sulfate and calcium nitrate applied by drip fertigation (no N as the control, CK) on grain yield, water use efficiency (WUE), N use efficiency (NUE) and N loss in wheat and maize. A total of 250 kg N ha−1 and 205.5 kg N ha−1 were split into six and four applications and applied by drip fertigation at key growth stages during the wheat and maize growing seasons, respectively. The results showed that urea and calcium nitrate produced higher yields (p