Split nitrogen sources effects on nitrogen use efficiency, yieldand seed quality of safflower (Carthamus tinctorius L.)

摘要

The effects of nitrogen (N) on crop yields have historicallybeen assessed with field trials, but selection and use of the bestsources and optimal timing N applications have a significant rolein realizing the maximum potential of oilseeds quality and quantity.This study was conducted to determine the combine effectsof N sources [ammonium nitrate (AN), ammonium sulphate(AS), sulphur coated urea (SCU), and urea (U)] and split N fertilisation[(1/4,3/4,0), (1/3,1/3,1/3), (1/2,1/2,0), and (1/3,2/3,0)] on safflower(Carthamus tinctorius L.) some growth characters, yield andseed quality, and N use efficiency based on a split plot designwith three replications at the experimental research station,Shiraz University in 2015 and 2016. The highest safflower drymatter (5140.93 kg ha–1), seed yield (3303.52 kg ha–1) and proteinyield (694.95 kg ha–1) were achieved with the application ofAN fertiliser in a split pattern of 1/2,1/2,0 (applying half of the Nat sowing time and the rest at stem elongation), while the highestoil yield (753.09 kg ha–1) was observed by U fertiliser and similarsplit pattern. Applying AN fertiliser and split patterns of 1/3,2/3,0(applying one third of the N at sowing and two thirds of the N atstem elongation) and 1/4,3/4,0 (applying one quarter of the N atsowing and three quarters at stem elongation) maximised safflowerN uptake efficiency (NUpE) (0.78 kg kg–1). However, thehighest N utilisation efficiency (NUtE) (43.70 kg kg–1) wasobtained when AN fertiliser in a split pattern of 1/2,1/2,0 wasapplied. On the contrary, applying AS and SCU fertilisers wasless effective on safflower performance by all split patterns. It isconcluded that applying AN fertiliser in a split pattern of 1/3,2/3,0and or U fertiliser in a split pattern of 1/2,1/2,0 not only enhancedsafflower growth, yield and seed quality improved, but alsoincreased the N use efficiency of safflower.