Effects of Interaction between Nitrogen Fertilizer and Density on the Yield and Agronomic Traits of Flax

The two factors randomized block field experiment was conducted to study the effect of nitrogen applied [no using N(0),conventional N(75 kg/hm2) and high N(150 kg/hm2)] and cultivation density(4.5 million seeds/hm2,7.5 million seeds/hm2 and 10.5 million seeds/hm2) on the yield,agronomic traits and quality of flax to determine the best combination of nitrogen fertilizer and density.The results showed that different nitrogen fertilizer and planting density had some effects on the yield,agronomic traits and quality of flax,among them,the number of branches,the number of capsules per plant and grain weight per plant under the high nitrogen and moderate nitrogen treatment were higher than that under the treatment of zero nitrogen application. Under the same nitrogen treatment,plant height,number of branches and the number of capsules per plant decreased with the increasing of the density.The nitrogen treatment had very significant effect on flax yield,among them,the yield difference between the high nitrogen and moderate nitrogen treatment was not significant, but the yield under which was extremely significantly higher than the one under zero nitrogen and the effect of moderate nitrogen treatment was extremely significantly higher than the one under zero nitrogen,while the effect of planting density and nitrogenfertilizer×planting density on yield were not significant, with the increasing of amount of nitrogenfertilizer, the content of flax oil decreased, butthe content of linolenic acid increased.When nitrogen was 150 kg/hm2 and density was 10.5 million seeds/hm2, the yield reached the highest whichwas 1 655.1 kg/hm2,it had no significant difference with the yield under the same nitrogen and 7.5 million seeds/hm2 treatment,in the same time,which had no significant difference with the yield under 4.5 and7.5 million seeds/hm2 treatment of 75 kg/hm2 nitrogen.Considering the input costs of seeds,fertilizer and the ratio of input and output,the economics scheme,when planting density was 4.5 million seeds/hm2 andnitrogen application amount was 75 kg/hm2,the yield could reach 1 523.4 kg/hm2 in this research.