稻草还田配施氮肥对烤烟生长发育及产质量的影响OA

To clarify the effects of rice straw returning and nitrogen application rate on the growth,development,yield and quality of flue-cured tobacco,and to optimize the cultivation model of flue-cured tobacco,a field experiment was conducted in Jintian Village,Dahu Town,Liuyang City,Hunan Province in 2024.A split-plot design was adopted,with straw returning amount as the main plot factor(H1:0 t/hm2,H2:2.8 t/hm2,H3:5.6 t/hm2)and nitrogen application rate as the subplot factor(N1:150.0 kg/hm2,N2:180 kg/hm2,N3:210 kg/hm2).The agronomic traits,SPAD values,yield and quality of flue-cured tobacco under different treatments were compared and analyzed.The results showed that,under the same straw returning amount,the agronomic traits at the mature stage and SPAD values at different growth stages increased with the increase in nitrogen application rate.However,the SPAD value of the N3 treatment declined slowly,which affected tobacco leaf maturity.The yield of cured tobacco leaves increased gradually,while the proportion of superior-grade leaves,average price and output value first increased and then decreased.The contents of total nitrogen and nicotine in cured tobacco leaves increased,whereas the contents of total sugar,reducing sugar and chloride decreased,and potassium content first increased and then decreased.Under the same nitrogen application level,increasing the amount of straw returning improved the agronomic traits of flue-cured tobacco.The SPAD value of fresh tobacco leaves first increased and then decreased.The yield,proportion of superior-grade leaves,average price and output value of cured tobacco leaves also showed a trend of first increasing and then decreasing.The contents of total nitrogen,nicotine,total sugar,reducing sugar and potassium first increased and then decreased,while the chloride content gradually decreased.Comprehensive analysis indicated that the H2N2 treatment could better improve the agronomic traits of flue-cured tobacco at the mature stage,enhance the photosynthetic rate during the growth period,and allow the SPAD value to decline in time,thereby ensuring timely maturity of tobacco leaves.Meanwhile,this treatment produced the highest output value of cured tobacco leaves and the most coordinated chemical composition,which is conducive to the production of high-quality tobacco leaves.