Effects Of Nitrogen Forms On The Growth And Development Of Grape

In order to study the effects of the forms and ratios of nitrogen on the growth and development of grape, Chardonnay grape seedlings, Kyoho and mature grapes were used as material to investigate the nitrogen forms on grape's physiological functions, and the suitable ratios of nitrogen forms for grape's growth. This research will provide theoretical guidance for the adequate fertilizer, and provides basis for realize high yield and high quality of grape. The main results were as follows:1. Matrix-nutrient solution containing higher proportion of nitrate nitrogen ((NO₃)^--N/(NH₄)⁺-N=70/30, 50/50) was better for grape growth compared with the single nitrogen. The fresh weight of Chardonnay grape seedlings and Kyoho reached the highest when the nitrate ratio was 70/30, 50/50, which was 1.4 and 1.6 times that of (NH₄)⁺-N treatment respectively; The dry matter weight of Chardonnay and Kyoho was the largest when the ratio of (NO₃)^--N/(NH₄)⁺-N was 70/30, which increased 42.8%, 81.8% respectively than that of complete (NH₄)⁺-N treatments.2. The higher proportion of (NO₃)^--N has active effects on nitrogen metabolism of grapes. The treatment of (NO₃)^--N/(NH₄)⁺-N ratios for 70/30 significantly increased the nitrogen absorption, transportation and accumul- ation the nitrogen absorptaiton ammuont in Chardonnay under this treatment was obviously higher than that of other treatments, which increased 67% compared with (NH₄)⁺-N treatment. The nitrogen absorption and reduction in grape was inhibited under (NO₃)^--N treatment, and the nitrogen accumulation was 81.3% of (NO₃)^--N/(NH₄)⁺-N ratios for 70/30. The nitrogen concentration and accumulation in roots, leaves, shoots of grape under (NO₃)^--N/(NH₄)⁺-N ratios for 50/50 was very high, and the total nitrogen accumulation was 2.3 times of that complete (NH₄)⁺-N.3. The NRA in Chardonnay leaves under the treatment with higher proportion of (NO₃)^--N was significantly higher than that of other treatments, and the value reached to the peak under the treatment with (NO₃)^--N/(NH₄)⁺-N ratios for 70/30, whereas the other treatments decreased by 39%, 49%, 64% respectively, compared with that of (NO₃)^--N/(NH₄)⁺-N ratios for 70/30. The value became lower with the increasing of the proportion of (NH₄)⁺-N in the roots, compared with that of (NO₃)^--N/(NH₄)⁺-N ratios for 50/50, the value of NRA decreased by 17% and 28% respectively under the treatment with (NO₃)^--N to (NH₄)⁺-N was 30/70 and 0/100.4. The ammonium was better for the improvement of roots P, K concentration, the value under the treatment with complete (NH₄)⁺-N nitrate treatment was 3.6 times and 1.38 times respctively as great as that of complete (NO₃)^--N treatment. P, K concentration in stems, shoots and leaves of Chardonnay fertilized with (NO₃)^--N/(NH₄)⁺-N ratios for 70/30 was higher, matrix-nutrient treatments were better for the increasement of P, K accumulation and total in the different organs. Under the treatment with (NO₃)^--N/(NH₄)⁺-N ratio was 30/70, the P total amount was 2.2 and 1.3 times as great as complete (NH₄)⁺-N and (NO₃)^--N treatment, respectively; and when the treatment with (NO₃)^--N/(NH₄)⁺-N ratio was 70/30, the K total amount was 2.03 times as great as complete (NH₄)⁺-N. The P, K absorption and accumulation of Kyoho was inhibited when (NO₃)^--N or (NH₄)⁺-N were applied. The total P accumulation was high when treated with mixd nitrogen, and the value reached to the highest when ratio of (NO₃)^--N/(NH₄)⁺-N was 50/50, which were 1.34 and 1.87 times of that treated with complete (NO₃)^--N and (NH₄)⁺-N respectively. The total amount of K accumulation in Kyoho reached to the highest when (NO₃)^--N/(NH₄)⁺-N was 50/50, and was 1.91 and 2.88 times of that treated with (NO₃)^--N and (NH₄)⁺-N, respectively.5. The Ca, Mg, Fe, Mn, Zn concentration in the roots of Chardonnay seedlings and Kyoho treated with complete (NH₄)⁺-N was significantly higher than that of complete (NO₃)^-N treatment, but higher proportion of (NO₃)^--N ((NO₃)^--N/(NH₄)⁺-N =0/100, 70/30) was beneficial for the leaves of Chardonnay seedlings and Kyoho to accumulate Ca, Mg, the concentration of trace elements was higher in the leaves of Chardonnay seedlings and Kyoho, which was treated with mixed nitrogen ((NO₃)^--N/(NH₄)⁺-N =70/30 , 50/50)6. The chlorophyll a content under treatment with (NH₄)⁺-N increased by 5% compared with that of (NO₃)^--N treatment, and chlorophyll b content decreased by 18.6%, the total chlorophyll value of a/b is 1.24 times of complete (NO₃)^--N treatment. Chlorophyll content in Chardonnay is maximum in the treatment which the ratio of (NO₃)^--N to (NH₄)⁺-N was 70/30, and increased by 25% and 26% respectively compared with complete (NO₃)^--N and (NH₄)⁺-N treatments. The photosynthetic parameters of Chardonnay treated with ratio of (NO₃)^--N to (NH₄)⁺-N was 70/30 was higher, and net photosynthetic rate increased by 12.6% and 20% compared with that of (NO₃)^--N and (NH₄)⁺-N treatment respectively.The starch and soluble sugar in roots and leaves of Chardonnay with mixed nitrogen treatments were relatively high, and the starch content in grape roots reached to the peak when the ratio of (NO₃)^--N to (NH₄)⁺-N was 50/50, which was 1.4 and 1.6 times of those plants treated with complete (NO₃)^--N and (NH₄)⁺-N respectively. The soluble sugar content of roots and leaves in treatment which ratio of (NO₃)^--N to (NH₄)⁺-N was 70/30 incresed by 37.8% and 108% compared with complete (NH₄)⁺-N treatment respectively. The starch and soluble sugar content of grape treated with (NH₄)⁺-N were 2.63 and 1.4 times of that treated with (NO₃)^--N.7. Foliar application of urea and mixed nitrogen nutrition ((NO₃)^--N/(NH₄)⁺-N = 70/30,50/50,30/70) was beneficial to increase fruit sugar, Vc, anthocyanin content sugar acid ratio in grape, and reduce titratable acid content. The accumulation of nitrate in fruit was reduced under treatment with mixed nitrogen; compared with clean water, the storage nutrition in grape branches under other treatment were improved significantly.