Absorption And Utilization Of N Nutrients By Flue-cured Tobacco And Effects Of Different Forms Of N Fertilizer On Yield And Quality Of Flue-cured Tobacco

With the deVlopmen of the Inethods ofplantin in W and field plot exPementand isotoPe bor teCboque. We StUdy the absorptiOn and utilhatiOn of N nutrients ofmain var~ Longjiang 9l l of flue-cured tObo of Heilongiiang PrOvince bom 20()0to 20()l; effectS of aPPlied different forrns of N fenilizer on yteld and quality offiue-cured tObacco. The WtS ofexperimen showed as follows:The absorption Peak of fiue-cured tobacco for N was in the period of 3l60 dayaller twlaning. The average day areumulallon level for N was 72.2medlant. dayffe N bopen oftotiacco uec- ~odly atw e0 dayS.The N accumulatons of flueroed tOwt thewt in the equence of bottomleavs, tOpping leaVeS, middle leaves; on cotw the propobo of fwhlbo Nabsorbed by fiue-ced tDbacco increased toPPing, mamle, botw leaVeS.The ratio of fenilizer N into tobacco leaVeS 'was hpe in seedling Stag taldecreased gradually with the extension of po~ period, bUt there were smalldiN bom budding tO mature Period.l5N twer shoed tha: In early growth period N absond by nue-cutal tObaccomainly cam from fenilher, 30 day after ~ the content of the N feniltherabsond by tObacco wt for 6()% of the tota N. With the develOPmen oftOhao,the uPch of fertilizer N by tobacco deCnd graduallyAfter the aPplication of lW fertilizer in soil, 39-53% of tOtal N was utilibo; 224l% lostby all N; 20-37% meM in soil.The experiment on different N fonns showed tha: with the e-ion of teS time,soil nibe N of each beanent deCnd intensely; but with the boo ofaPplicatbo ofammonium N increaSed, soil anunonium N incnd ~tally The aPPIOghate thes ofnitrOgen was 3 deu in the Style of 75% NO3W + 25% Wh+W, com~ tO all Othertreatments, the resultS of exPeriment had a higher potaSsiuny reduCing sugn nicotine,total N and the ratio among several chemical comPOsitions were aP in cund leaVeS. Thequality ~s and vaue in cured leaves were the higheSt. In genera, it is the best if75%NOsW + 25% Wh+N at 3 kglmu is adoptal in field under the soil and weathercondition in Heilongiiang Province...