Effect of different nitrogen forms and their ratio on agronomical character,economic and quality of flue-cured tobacco

In Hunan Liuyang,with the field trials,the effect of ratio of nitrate nitrogen to ammonium nitrogen(RN) on(agronomical) character,economic and quality of flue-cured tobacco were studied.The results showed: 1) RN didn't (influence) the leaf width,leaf long,leaf area,yield,productive value and average price of flue-cured tobacco,but had significant effect on grad composing,content of chemical component and the accumulation of N,K and Cl.Within limited rang of RN,the relations between yield,average price,yield of high grad tobacco,yield of low grad tobacco,nicotin,N,reducing sugar,Cl,amylum,volatile base and the quotient of ammonium would been described by significant quadratic polynomial,and the relations between K and the quotient of ammonium conformed to negative linear equation;2)With a RN of 75%∶25%,the value of proportion of high and middle grad tobacco,content of nicotin,N,K,uptake of N and K/Cl were the highest,volatile base was lowest.When RN was 25%∶75%,N and amylum were lowest,and volatile base were highest.With 100% ammonium,reducing sugar,Cl and amylum were highest,and K/Cl,nicotin and K were lowest.With 100% nitrate,the content and uptake of N,K and Cl were the lowest;3) Any RN,the content of nicotin,N,K,Cl and amylum satisfied the demand of high quality tobacco,reducing sugar was on the other way round.Taking economy,nutrition utilization and chemical quality into consideration,the suitable RN would be(54%∶46%)50%∶50%.