Effects Of Applying Modifiers On Physical And Chemical Properties Of Acid Soil And Growth Of Flue-cured Tobacco

In recent years,the acidification of tobacco-growing soil which has restricted the sustainable production of high-quality tobacco leaves,has caused the deterioration of soil physical and chemical properties and the increase in the incidence of tobacco diseases,.Aiming at the problem of soil acidification,combined with the effect of modifiers on tobacco-growing soil,A field experiment of three factors×two levels with partial Eta~2value were used to study the effects of modifier types,application time and amounts on on the physical and chemical properties of acid soils.The main findings are as follows:(1)Application of improvers can increase soil organic matter content,soil alkaline nitrogen content,soil available phosphorus content,and decrease soil bulk density;application of improvers during flue-cured tobacco site preparation can increase soil available potassium content,while application of cured soils will decrease Soil available potassium content.(2)Application of modifiers can significantly increase soil pH and base saturation,and significantly reduce soil exchangeable hydrogen,exchangeable aluminum,and hydrolysable acids,but its improvement effects will decrease with time;both soil modifiers the cation exchange capacity of the soil increased only in the early stages.For acidic tobacco planting soil,the application of 1500kg/hm~2of lime during flue-cured tobacco film mulching soil had the greatest effect on the soil acidity indexand the best improvement effect,followed by the application of 750kg/hm~2of lime during flue-cured tobacco film mulching soil improvement.(3)The application of low-dose lime was beneficial to the growth of flue-cured tobacco plant height and stem circumference before topping,and the application of acidic soil conditioner was beneficial to the growth of flue-cured tobacco leaves before topping.The application of modifiers mainly affected the economic traits index of flue-cured tobacco,the single leaf weight of tobacco leaves,and the total nitrogen content of tobacco leaves.The amount of modifiers has the greatest effect on the economic characteristics of flue-cured tobacco.The interaction between the types of modifiers and the application time has the largest effect on the physical characteristics of tobacco leaves.The composition has the greatest effect on chemical composition.(4)The application of the modifier can effectively improve the top-grade tobacco ratio,average price,yield,output value,and index of economic traits of tobacco,physical index of tobacco leaf,and availability index of chemical composition of tobacco leaf.In production,an acidic improver is used,and it is best to apply 1500kg/hm~2of lime during the preparation of the flue-cured tobacco.When the tobacco is exposed to film and soil,applying1500kg/hm~2of an acidic soil conditioner is the best.(5)Relative to the physical and chemical characteristics of the soil,at 60 days after the flue-cured tobacco was transplanted,the application of modifiers mainly affected soil exchangeable hydrogen(accounting for 73.33%),cation exchange capacity(accounting for53.85%),and alkaline nitrogen content(accounting for 43.22%)And bulk density(accounting for 34.29%);at 90 days after,the soil organic matter content(accounting for37.78%),bulk density(accounting for 34.29%),exchangeable aluminum(accounting for32.43%),and pH(accounting for 30.89%)were mainly affected;at 120 days after,It mainly affected soil available phosphorus content(accounting for 50.00%),available potassium content(accounting for 38.28%),exchangeable aluminum(accounting for 35.14%),and hydrolytic acid(accounting for 22.63%).The types of modifiers mainly affected soil organic matter(accounting for 45.28%)and soil available phosphorus(accounting for 57.14%).The application time of modifiers mainly affected soil available potassium(accounting for31.44%).The amount of modifiers mainly affected soil bulk density(accounting for 89.74%)and soil alkaline nitrogen(accounting for 30.00%).(6)The economic traits index(accounting for 24.17%)in the economic traits index,the single leaf weight of tobacco(accounting for 21.03%)in the physical characteristics index of tobacco,and the total nitrogen content in the chemical composition index of tobacco leaf(accounting for 22.22%)has the greatest impact;the amount of modifier has the greatest effect on the economic traits of flue-cured tobacco(accounting for 32.74%);the interaction between the type of modifier and the application time has the largest effect on the physical properties of tobacco leaves(accounting for 19.63%);the type of modifier has the largest effect on chemical components(accounting for 21.21%).