Effects Of Different Fertilization Treatments On Soil Properties,Tobacco Growth And Tobacco Quality In Tieling

Tieling City is the main tobacco growing area in Liaoning Province.Long-term unreasonable fertilization by tobacco farmers has resulted in the destruction of soil structure and the decrease of organic matter content,which affects the yield and quality of tobacco leaves.In this study,the field test method was used to systematically study the effects of different microbial fertilizer content combined with different tobacco compound fertilizer content on tobacco planting soil,tobacco plant growth and quality in the area,in order to reduce the content of chemical nitrogen fertilizer,improve the yield and quality of tobacco leaves,find the effects of microbial fertilizers and chemical fertilizers on the nutrient effect of tobacco planting soil and tobacco growth indicators,yield and quality,provide a theoretical basis for rational tobacco planting in this area.On the basis of the conventional fertilization rate in the field,the tobacco compound fertilizer was reduced by 10%,15%,and 20%,and the microbial fertilizer was increased by 1200 kg·hm^-2,1500 kg·hm^-2,and 1800 kg·hm^-2 at the same time.A total of 9fertilization treatment,conventional fertilization as a control,the research results are as follows:（1）Compared with local conventional fertilization,the combined application of microbial fertilizer and tobacco compound fertilizer can reduce soil bulk density,increase soil water content and porosity;The soil water content increased by 0.02%-11.89%and 2.67%-11.91%in the resettling growth stage and fast-growing stage;The soil bulk density decreased by 1.48%-5.33%,2.62%-14.83%and 0.74%-22.17%in resettling growth stage,fast-growing stage and mature stage;Soil porosity increased with the increase of microbial fertilizer application.（2）Compared with local conventional fertilization,increased application of microbial fertilizer can significantly increase soil total nitrogen and organic carbon content,and during fast-growing stage,soil total nitrogen and organic carbon content increased by 3.07%-13.21%and 4.08%-13.20%.The content of available nutrients such as soil available potassium and alkali-hydrolyzable nitrogen increased significantly,the content of available potassium increased the most.The content of soil available potassium increased by 51.84%and 23.31%when tobacco compound fertilizer reduction by 10%and 15%combined with high amount of microbial fertilizer at the resettling growth stage.（3）Compared with local conventional fertilization,the combined application of microbial fertilizer and tobacco compound fertilizer can improve soil enzyme activity and microbial biomass carbon and nitrogen in varying degrees.Tobacco compound fertilizer reduction of 15%combined with high-amount microbial fertilizer significantly improved soil urease,invertase and catalase activities,increasing by 63.43%,30.05%and 20.90%respectively in the fast-growing stage;Tobacco compound fertilizer reduction of 10%combined with the treatment with high amount of microbial fertilizer was the second;The tobacco compound fertilizer was reduced by 15%,and the treatment with high amount of microbial fertilizer treatment increased the carbon and nitrogen content of soil microbial biomass by 108.08%and 75.62%in the fast-growing stage.（4）Compared with the local conventional fertilization,the application of microbial fertilizer can improve the agronomic traits of tobacco,and it increases with the increase of the application rate,and the effect on the fast-growing stage is greater than that in the resettling growth stage.The combined application of microbial fertilizer and chemical fertilizer increased the yield of tobacco by 1.39%-21.09%;improved the quality of tobacco leaves,reducing the amount of tobacco compound fertilizer by 15%and applying high amount of microbial fertilizer to increase the potassium content of tobacco leaves by 13.65%,total sugar content by 23.94%,nitrogen content by 19.33%,The nicotine content is 3.68%,which reduces the chlorine content and schmuck value of tobacco leaves,and the chemical composition of tobacco leaves is more coordinated.In conclusion,increasing the application of microbial fertilizer is beneficial to improve soil quality,tobacco yield and tobacco quality in Tieling tobacco-growing area.Among them,reducing the application amount of tobacco compound fertilizer by 15%and applying high amount of microbial fertilizer had the best effect,that is,the application amount of microbial fertilizer was 1800 kg·hm^-2,and the application amount of tobacco compound fertilizer was225 kg·hm^-2.