| At present, N fertilizer application was the same in different available nitrogen soil in Fujian tobacco planting area, which resulted in inharmonic carbon-nitrogen metabolism. And the nicotine content of 80% of the upper leaves were higher, leading to low industrial availability.Field and pot experiments were carried out to study the effects of various nitrogen levels on carbon-nitrogen metabolism and the quality of tobacco leaves in different available nitrogen soil. The experiment suggested the reasonable N fertilizer application meeting the harmonization of carbon-nitrogen metabolism and high-quality tobacco leaf in different available nitrogen soil.These would offer a certain scientific basis for reasonable N fertilizer application.1.The results of pot experiment showed that:25 days after transplanting, when N fertilizer application was 1.90g/pot(N5 treatment), the height was increased by 6.25%-31.7%; in tidal field(105.45mg/kg);the height of N4 treatment was increased by 10.61%-38.61%,and the average leaf number was more tnan those of other treatments by 0.5-2 pieces in yellow mud field(127.27mg/kg);the growth of N3 treatment was the best,but that of N5 treatment was inhibited in paddy field(184.31mg/kg).The growth of N5 treatment in tidal field,N4 treatment in yellow mud field and N3-N5 treatment in paddy field respectively were the best 75 days after transplanting.In tidal field, no N fertilizer application treatment had no rosette and squaring stage. Under the condition of 0.45 and 0.90g/pot N, the rosette was deferred by 10-15 days and the squaring stage was by 10-19 days. At the mature stage of flue-cured tobacco, the biomass of N5 treatment was the largest and increased by 28.99%-397.65%compared with those of other treatments.In yellow mud field, the growth and development of N4 and N5 treatments was fine; whose growth periods were 106-113 days. Under the condition of 0 and 0.45g/pot N, the rosette and squaring stage appeared 70 days after transplant later; showing premature senescence.N3 treatment (0.90g/pot) was harvested 20 days in advance than N5 treatment. The total biomass of N3-N5 treatments was significantly higher than that of other treatments; dry weight of N5 treatment's leaves was the largest and reached to 48.1171g in yellow mud field. The biomass of N4-N5 treatments in paddy field was significantly higher than that of other treatments. But the growth periods delayed to 122-131 days, causing reluctant ripen late-maturing because of over-application N fertilizer. At the anaphase, middle and upper leaves of no-nitrogen fertilizer treatment turned yellow earlier for inadequate N fertilizer supplication. The growth and development of plants with 0.45-0.90 g/pot N fertilizer application was better in paddy field.2. In tidal field (105.45mg/kg), the NR activity, chlorophyll, soluble protein and amino acid contents kept low level during the whole growth period under the condition of 0-0.45g/pot.With the same N level, the carbon accumulation metabolism increased and pooled more carbohydrate at the prophase but less at the anaphase which showed N deficiency. The total soluble sugar and reducing sugar contents of N4-N5 treatments were higher at the anaphase which was helpful to the synthesis of starch. The reduced carbohydrate contents of N5 treatment was the largest and the nitrogen contents ranged from 1.45% to 1.98% at harvest.30 days after transplant, invertase activities of tobacco leaves had no significant differences each other in yellow mud field and paddy field. 55 days after transplant, the invertase activities of N5 teeatment in yellow mud field and N4-N5 teeatments in paddy field were significantly higher than those of other treatments, separately coming to 29.4822 mg.g-1Fw.h-1,29.8196 mg.g-1Fw.h-1, 24.1300 mg.g-1Fw.h-1 in yellow mud field, the chlorophyll contents were 1.995mg.g-1Fw.h-1 and significantly higher than those of other treatments 75 days after transplant with N application of 1.35-1.90g/pot. At the same N level, the the soluble sugar contents were higher than those of N1- N3 treatments at anaphase, and less than those of N1-N3 treatments at the prophase growth. 55 days after transplant;the soluble protein contents were more than those of other treatments, and more amino acid was synthesized protein.The nitrogen content of lower leaf of N1-N3 treatments and midddle-leaf of N1 treatment respectively were 1.22%,1.32%,1.44%,1.43%,keeping a lower level.In paddy soil(184.31mg/kg), when N fertilizer application was 1.35-1.90g/pot, the stalk contents were extremely low. Under the condition of no more than 0.45 g/pot N fertilizer, the sobule sugar contents increased by 38.23%-103.19%, meanwhile the contents of reducting sugar and stalk also were higher compared with those of other treatments 55 days after transplant.75 days after transplant, the chlorophyll content was 2.095 mg.g-1Fw.h-1 which still kept a higher level by N5 treatment.Furthermore, the soluble protein and amino acid contents were significantly higher than those of other treatments. 3. The results of field experiment indicated that: In yellow mud field(105.61mg/kg),gray-xanthic sandy paddy soil(142.29mg/kg)and albic gray paddy soil|(168.37mg/kg),the growth,yield and output value of no N fertilizer treatment were extremely lower than those of other treatments, and leaf quality was poor with weight per leaf less than 5g. In yellow mud field (105.61mg/kg), when N fertilizer application was 165.0-192.0 kg/ha, the growths were better, the yields reached 2300 kg/ha above and the output values were 25000 yuan/ha above. Under the condition of 165.0 kg/ha N fetilizer, nitrogen/nicotine of upper, middle and lower leaf of Fured-cure tobacco separately were 0.54:1,0.81:1,1.66:1and the ratio of total sugar to nicotine in upper-leaf was11.64:1;nitrogen/nicotine of 192.0 kg/ha N fertilizer were 0.63:1,1.06:1,1.05:1 and total sugar/nicotine of upper leaf was 12.09:1; which were close to international high-quality requirementsof nitrogen/nicotine(0.5-1:1),totalsugar/nicotine (10-15:1).Thus, carbon and nitrogen metabolism of tobacco leaf was coordinated under the 165.0-192.0 kg/ha N fertilizer.When N fertilizer application was 0 and 97.5 kg/ha, the nicotine and nitrogen contents of different part tobacco leaves were lower. And the ratios of total sugar to nicotine of lower leaf respectively were 164.32:1,114.76:1, which leading to severely inharmonic carbon-nitrogen metabolism of tobacco leaf.The ratios of total sugar to nicotine in lower leaf respectively were 73.08:1,52.38:1under the condition of 120.0-142.5 kg/ha, bringing out slightly inharmonic carbon-nitrogen metabolism.In gray-xanthic sandy paddy soil(142.29mg/kg), the growths of E-F treatments (165.0 -192.0kg/ha) were better, However,the height of F treatment was 47.83cm,decreasing by 16% or so than those of other treatments.The yield,output value,averager price of flue-cured tobacco were higher than those of other treatments,resepratively reached 2300 kg/ha above,25000 yuan/ha above,11.00 yuan/kg above under the condition of 142.5-192.0kg/ha N.The ratios of nitrogen to nicotine of the upper and middle leaf by E treatment and the upper,middle and lower leaf of F treatment ranged from 0.5:1 to 1:1, the total sugar/nicotine of the upper and middle leaf by E treatment were 11.72:1, 14.34:1, meeting to the requirements for high-quality tobacco leaf.The total sugar/nicotine of the upper and middle leaf were 9.68:1, 18.20:1 by F treatment.In albic gray paddy soil|(168.37mg/kg),under the condition of 165.0kg/ha N(E treatment), the growth , yield, output value and averge price were the best.Furthmore,C and D treatments had little difference with that of E treatment, whose mid-grade and top-grade tobacco leaf rates were better than that of E treatment. The nicotine contents of E and F treatment's upper leaves were higher than 3.5%, which caused total sugar/nicotine decreasing, and only respectively were 7.44:1,7.21:1.The nicotine contents of A and B treatment's middle and lower leaves were less than 1%,and the carbohydrate contents were higher so ratios of nitrogen to nicotine separately were 1.99:1,2.33:1;1.58:1,2.23:1,and their ratios of total sugar to nicotine were 46:1 above.When N fertilizer application was 120.0-142.5 kg/ha, the content of nicotine,nitrogen, total sugar,reducing sugar and ratios of carbon to nitrogen were appropriate in flue-cured tobacco leaves.Considering the yield and output value, the growth condition, ratios and contents of carbon -nitrogen compounds in leaves of flue-cured tobacco from the field experiment,It was suggested that 165.0-192.0 kg/ha N fertilizer application in yellow mud field (105.61mg/kg), 165.0 kg/ha in gray-xanthic sandy paddy soil (142.29 mg/kg) ,120.0-142.5 kg/ha in albic gray paddy soil (168.37 mg/kg) were conducive to the formation of high-quality tobacco leaf and harmonization of carbon-nitrogen metabolism.
|
PDF Full Text Request