Row Spacing and Plant Spacing on Nitrogen Metabolism in Flag Leaves and Grain Protein Content of Winter Wheat

Field plot experiments were carried out to examine the effects of row spacing and plant spacing on nitrogen metabolism of flag leaves and grain protein content in winter wheat on the farm of Henan Agricultural University during 2005~2007.Four ratio of row spacing to plant spacing with 1.5(RP1),6.0(RP2),10.5(RP3) and 15.0(RP4) were respectively arranged in a randomized block design with three replicates.The results showed that N content and NR activity in flag leaves decreased gradually with the process of grain filling,GS activity tended to single peak curve.The N content of flag leaves was increasing with decreasing ratio of row spacing to plant spacing in whole filling stage,with obvious superiority for 6 of ratio of row spacing to plant spacing in later filling stage.It reveals that a suitable combination of row spacing and plant spacing could effectively improve conditions of wind and light,promote N absorption and transportation.The NR activity of flage leaf in RP2 treatment was the highest in filling stage,with next for RP1 and steadily decline for ratio of row spacing to plant spacing over 6.The GS activity of flage leaf in RP2 and RP1 treatments were higher during 0~7 days after anthesis,and the GS activity in RP2 was the highest after 14 days after anthesis with next for RP1 and RP3,the lowest for 15 of ratio of row spacing to plant spacing.The protein content,grain yield and protein yield of RP2 treatment were the highest with harmonizing yield structures and N absorption and transportation,and increased significantly protein content and grain yield,with better treatment of RP1 for increasing yield and improving quality.Therefore the optimum distributing form for winter wheat was to reduce row spacing,enlarge plant spacing and keep suitable ratio of of row spacing to plant spacing.