Effect of different nitrogen level on nutrients accumulation, transfer and nitrogen utilization efficiency of dry land oil flax

Abstract

Field experiments were carried out to determine the effect of different nitrogen application rates on nitrogen nutrient uptake,transfer and nitrogen utilization efficiency of dry land oil flax. The results indicated that different nitrogen application rates affected nitrogen nutrient uptake,accumulation and transfer at different growth stages,and changes tendencies were consistant. The amount of nitrogen translocation from leaf,translocation efficiency and contribution to grain were 89. 18%,83. 36% and 86. 36% higher than from stem. The nitrogen in grain,among which 47. 10%-57. 66% was transferred from leaf,22. 46%-30. 94% was transferred from stem and 21. 00%-30. 48% was absorbed from soil. The result indicated that compared to no nitrogen application,the yield of nitrogen treatments( as 27. 6,55. 2 and 82. 8 kg·hm-2) increased 10.21%,16.92% and 15.55%,respectively. The nitrogen transfer amounts,transfer efficiency and contribution efficiency of leaf and stem to grain were maximum when the nitrogen application rate was 55. 2kg·hm-2. With increased nitrogen application rate,apparent nitrogen recovery efficiency of oil flax first increased then decreased. The partial nitrogen factor productivity of oil flax decreased significantly. After taking into account of grain yield,nitrogen utilization efficiency and ecological environment,the recommended nitrogen fertilizer rate for dry land oil flax was 27. 6-55. 2kg·hm-2at the soil fertility level in our experiment.