Effects of Irrigation Amount on Absorbability and Translocation of Nitrogen in Winter Wheat

The experiment on absorbability and translocation of nitrogen in winter wheat with two irrigation regimes and two cultivars was conducted at agricultural experiment station of Shandong Agricultural University, which was located in the central zone of main winter wheat production area in famous Huang (Yellow river)-Huai (Huai river)-Hai (Hai river) plain in China. Under the conditions of the experiment, the nitrogen uptake from soil ranged from 75.77% to 83.09% and from 79.31% to 83.74% at anthesis and maturity respectively. During grain filling, more irrigation could make the percentage of nitrogen uptake more from fertilizer, and less from soil for organs of winter wheat. The nitrogen contribution to grain, which came from the nitrogen stored in vegetable organs before flowering, ranged from 67.47% to 83.37%. The largest contribution of nitrogen to grain was from the stem or sheath, although the amount of leaf nitrogen was the greatest. More irrigation could promote the nitrogen translocation from vegetative organs to grains, and increase the yields of total nitrogen and biomass.