蔬菜—烤烟轮作模式下氮肥调控对烟叶产量与品质的效应研究OA

Under different crop rotation patterns(Chinese cabbage-tobacco,cucurbit-tobacco and celery-tobacco),five nitrogen fertilizer levels(0,55%,70%,85%,and 100%of conventional nitrogen application,denoted as N0,N55,N70,N85 and N100)were established to investigate the effect of nitrogen fertilizer regulation on tobacco yield,quality,nitrogen use efficiency and soil nitrogen balance.The results showed that moderate nitrogen reduction synergistically improved tobacco yield and quality.Among the crop rotation patterns,the Chinese cabbage-tobacco and cucurbit-tobacco rotations achieved the highest output value at N70 treatment(nitrogen application of 84 kg/hm2),reaching 102 032.17 yuan/hm2 and 95 937.44 yuan/hm2,respectively,while the celery-tobacco rotation achieved the highest output value at N55 treatment(nitrogen application of 66 kg/hm2),totaling 94 617.55 yuan/hm2.As nitrogen application increased,the total nitrogen,nicotine,and petroleum ether extract content in tobacco leaves significantly rose,but excessive nitrogen application led to an imbalance in the sugar-to-nicotine ratio.In the Chinese cabbage-tobacco rotation,the N70 treatment exhibited the highest nitrogen fertilizer utilization rate and nitrogen agronomic efficiency,at 47.49%and 9.71 kg/kg,respectively.Soil nitrogen balance analysis indicated that moderate nitrogen application improved soil nitrogen supply,whereas excessive application resulted in nitrogen surplus and increased environmental risks.In conclusion,it is recommended to apply 70%of conventional nitrogen application in Chinese cabbage-tobacco and cucurbit-tobacco rotations,and 55%in celery-tobacco rotation.