Effects Of Fertilization On Soil Physical And Chemical Properties,agronomic Traits And Economic Characters Of Flue Cured Tobacco In Yanan

In order to sovle the reduce of yield and quality of Yanan flue-cured tobacco in recent years,three different soil improvement schemes were set up with cake fertilizer,humic acid fertilizer and bio-organic fertilizer,in order to restore the quality of soil in Yanan tobacco field.In this experiment,during the main growth period of flue-cured tobacco,by measuring the agronomic traits such as the height of the tobacco plant,the stem circumference,the number of effective leaves,the leaf length,the maximum leaf area and other agronomic traits,the development of different soil improvement measures on the growth and development of tobacco leaves was studied.The effects of different soil improvement measures on the soil physical and chemical properties of tobacco fields were analyzed by measuring the contents of organic matter,soil water content,pH value,alkali hydrolysable nitrogen,available phosphorus and available potassium,and the effects of different soil improvement measures on the tobacco economy were analyzed by the statistics of tobacco yield,upper tobacco and medium smoke ratio.The effect of the character.Aiming at the harm of continuous cropping obstacles and excessive chemical fertilizer,the optimal fertilization scheme to improve the yield and quality of Yanan flue-cured tobacco was explored,and the tobacco production in this area was directed to realize the sustainable development of the tobacco industry.The main results are as follows:1.The physical and chemical properties of different soil layers in six typical tobacco fields in Yanan were analyzed.The pH value,organic matter,available phosphorus,ammonium nitrogen and nitrate nitrogen were measured.The results showed that the average value of pH was 7,7.11 and 7.37 when soil depth was 0-30,30-60 and 60-90cm,and the deeper the soil was,the more alkaline soil was.The average content of organic matter in all soil samples is about 22g/kg.With the deepening of soil layer,the content of soil organic matter is also increasing.The average content of available phosphorus is about 76mg/kg,and there is little difference in available phosphorus content in different soil layers.The average value of ammonium nitrogen content is 130mg/kg,and there is little difference in ammonium nitrogen content in different soil layers.The average content of nitrate nitrogen is 91mg/kg,and the content of nitrate nitrogen decreases with the deepening of soil layer.2.Field experiments were conducted to increase the effect of cake fertilizer on the growth of Flue-cured Tobacco by adding different proportions of cake fertilizer on the basis of local fertilization.The results showed that cake fertilizer could obviously increase the height of plant and the number of leaves in the middle and late stages of the middle and late stage of tobacco growth,and had little effect on leaf length and leaf width.Cake fertilizer can promote the late growth of flue-cured tobacco and prolong the growth period.Cake fertilizer can increase the yield under low dosage.Considering that the amount of cake fertilizer is controlled in 150kg/hm~2,it is more suitable.3.The field test and humic acid fertilizer were set up.The results showed that humic acid could regulate the soil PH and increase the content of N,P and K in the soil,which had significant effect on improving the yield and quality of tobacco leaves.However,attention should be paid to the control of humic acid.Too much humic acid will impede the growth of tobacco leaves.Generally speaking,150kg/hm~2 is suitable.4.Effects of combined application of bio organic fertilizer on soil physical and chemical properties,agronomic traits and economic traits in Yanan tobacco fields.The effect of bio organic fertilizer on soil pH was not significant,but the content of nitrogen,phosphorus and potassium in the soil was obviously enhanced,and the yield and the proportion of the upper tobacco increased significantly with the use of bio organic fertilizer.There is little difference in the characteristics between the treatment of adding bio organic fertilizer and the use of biological organic matter fertilizer at the same time reducing the amount of fertilizer use,and the proportion of the upper grade tobacco leaves is higher after the reduction of chemical fertilizer.Therefore,a proper amount of bio organic fertilizer(Nan niwan 150kg/hm~2,Niu Wu 225kg/hm~2)can balance the soil nutrition,improve the yield and quality of tobacco leaves.Comprehensive analysis,Yanan tobacco field can appropriately reduce the amount of fertilizer application and increase organic manure,while regulating soil organic matter,it can increase soil porosity,improve soil adsorption capacity and water conservation ability.So as to improve the production and quality of the foundation.