Influence Of Different Nitrogen Forms On Growth And Nutrition Of Sugarbeet

NongHua 9808 were used to study the influence of NO3- -N and NH4+-N on plant growth and mineral nutrition. The results showed that:(1) The activity of nitrate reductase(NR) didn't increase along with increase of NO3- -N, and there was the highest activity of NR in leaves when NO3-/NH4+ was 70:30; The different ratio of NO3-/NH4+ changed the trend of activity of NR in roots.(2)Different nitrogen forms coexisted, the increase of NH4+-N had enhanced the absorption and utilization of N,P, Fe & Zn, Existence of nitrogen improved the contents of K+,Na+.(3)NH4+-N promoted the cumulation of amino acid in leaves; but amino acid in roots was the highest when NO3- / NH4+-N ratio was 70:30. (4) N forms influenced the activity of invertase enzyme , the contents of reductive sugar and sucrose. Suitable ratio of NH4+-N improved the yield and quality of sugarbeet. When NO3- / NH4+-N ratio .was 30/70,50/50 and 50/50 respectively, the sugar content, beet yield and sugar yield were the highest respective. The result could be theoretical fundament for optimizing fertilization and improving of yield and quality of beet sugar.