Study On The Mechanism And Application Of Flue-cured Tobacco Growth Of Different Designed Fertigation Pattern

In order to find the avaliable fertigation pattern that can be used in flue-cured tobacco production,4 different water and fertilizer management pattern were designed and put into used based on nutrition requirement characteristics and related water-fertilizer coupling model.Through their effects on tobacco growing development,dry matter accumulation et al.,we want to find the best suitable fertigation pattern that can be use in tobacco field planting,as well as provide theoretical foundation for water and fertilizer management system of tobacco.The result shows that:（1）Compared with the control group,all fertigation patterns had a significant effects on promoting the growth and development and increasing the plant height and leaf area of flue-cured tobacco.Among all the patterns,pattern T1 had the maximal leaf area which had improvements of about 27.2%compared with the control grop.Besides,Besides,though both the fertilizing amount of T2 and T3 are just 80%of CK,their plant height and leaf area were still significantly higher than the control group,which showd that slightly reducing the fertilizing amount while using the integration of water and fertilizer wouldn’t impose restrictions on the growth of tobacco.（2）The peak of N itrate reductase activity of all pat terns appeared on the 60d after planting,while the peak of Amylase activity appeared on the 75d.Then,both of them lowered.Compared with the control group,N itrate reductase and Amylase activity are both significantly higher than the control group,besides the changes of N itratase and Amylase activity were more suitable for carbon-nitrogen metabolism of flue-cured tobacco.（3）Compared with the control group,all fertigation patterns had a significant effects on increasing the content of revertose and to tal sugar and reducing the content of starch and nicotine.Besides,different patterns had different effects on the content of Potassium of tobacco leaf.Compare with pattern T1 and T2,pattern T3 had a significant effects on reducing the loss of potassium of tobacco leaf,which could increase the content of potassium of leaf before harvesting to some extent.（4）The accumulation of dry matter,nitrogen and potassium mainly happened in the5^9th week after planting.Besides,the total dry matter,nitrogen and potassium accumulation of tobacco plants that used fertigation pattern were high than the compared plants at the same growth period.Furthermore,the amount of dry matter,nitrogen and potassium accumulation in flue-cured tobacco were 5526.72,80.09,95.99 kg/hm²respectively with fertigation pattern T1;5027.05,75.01,92.72 kg/hm² respectively with pattern T2;while 5161.32,75.01,92.72 kg/hm² respectively with pattern T3.（5）Compared with the control grop,all fertigation patterns had a significant effects on enhancing the yield and output value of flue-cured tobacco.Among all the patterns,T1respectively inhanced the yield an output value of flue-cured tobacco by 27.1%and 18.8%,while T3 were 16.3%and 7.4%.The results showed that all designed fertigation pattern especially pattern T1 and T3could not only stimulated the growth of tobacco,increased the potassium accumulation uptake,but also enhanced the yield and output value.Based on the design parameter of T1and T3,165kg/hm² act as the total nitrogen application rate,4:6 act as dressing ration,the 3topdressing respectively accounted for 15%,75%,15%of total nitrogen topdressing amount,and N:K₂O respectively act as 1:1,1:3,1:3 can be considered as the reference model of fertigation pattern used in flue-cured tobacco production.Besides,under different environment,the design of fertigation must based on nutrition requirement characteristics and related water-fertilizer coupling model and weather situation et al.so it can have the best performance in flue-cured tobacco production.