| The nutrient status of soil planting tobacco and chemical of flue-cured tobacco leaves in several villages and towns at Xiangcheng County of Xuchang City was studied in the year of 2014 and 2015,the correlation K,Cl,S between soil and tobacco in different crops for rotation and cropping system.At the same time,the difference of the nutrient of soil planting tobacco,the tobacco growth,the absorption and accumulation of mineral element which effect the combustibility of tobacco and tobacco quality was analyzed in the existing local cropping patterns of continuous cropping,flue-cured tobacco and sweet potato intercropping,flue-cured tobacco and wheat intercropping,flue-cured tobacco and sweet potato with wheat intercropping,maize stubble.The correlative component about the combustibility of tobacco was studied the interplanting of tobacco and salsa.The results were as follows:1.The interplanting phenomenon of tobacco in Xiangcheng County is widespread in recent years,the nutrient of soil planting tobacco and tobacco leaf quality had great difference.For the average part of each village and town,soil organic matter content and soil p H was relatively high,Cl-1content was different in different place and the content all high,effective sulfur content is relatively low,available potassium,available phosphorus and alkali solution nitrogen average content were all in the appropriate range.The content of reducing sugar and total sugar were slightly high,nicotine and protein both were in the suitable range,the chlorine content of tobacco leaves were high,and the chlorine content of each model had great difference,the combustibility of tobacco was poor.2.Tobacco smoldering time was closely with soil planting tobacco nutrient and chemical component of tobacco,the contribution of soil nutrients index and the chemical component of tobacco leaves were different to the smoldering time through grey correlation analysis about tobacco smoldering time,soil nutrient and chemical component of tobacco,soil organic matter,Nitrogen and chlorine ion content had the higher contribution,and reducing sugar,protein and chlorine in tobacco had the higher contribution.To the all,the soil organic matter and protein in Xiang county isrelatively appropriate,it means that chlorine is the main factor affecting the combustibility of tobacco in Xiang county.So how to reducing the chlorine content of tobacco in Xiang County will be the major breakthrough to improve the combustibility of tobacco.3.the organic potassium index of flue-cured tobacco was poor in Xiang Country.Part of sample was still negative.Significant difference between body parts.The organic potassium index of lower leaf was minimum,the upper leaves was high and the combustibility of tobacco was good.At the same time,the organic potassium index of the different parts of flue-cured tobacco and smoldering time showed significant correlation.With tobacco potassium chloride sulfur content and sulfur content of soil potassium chloride were also showed significant correlation.That organic potassium index can be a very good characterization of tobacco combustibility and combustibility related indicators content.4.Soil chloride ion was high in different cropping patterns,soil organic matter,available K and available P were suitable.Soil p H was in the appropriate range under the tobacco continuous cropping,and the other patterns were high;The alkaline nitrogen was low in the patterns of flue-cured tobacco and wheat intercropping and maize stubble,and the other patterns were in appropriate range.Soil fertility suitability index showed maize stubble > continuous cropping > flue-cured tobacco and sweet potato intercropping > flue-cured tobacco and sweet potato with wheat intercropping > flue-cured tobacco and wheat intercropping in different mode,the pattern of maize stubble and flue-cured tobacco and sweet potato intercropping had better soil fertility.Soil fertility suitability of maize stubble was 0.6613,besides,the yield and quality of tobacco were better under maize stubble mode.5.Five modes were studied in the growth period of tobacco,soil available potassium was higher in the soil tilth of 0-10 cm when it compared with others,the soil available potassium content of different patterns was different,the available potassium content of flue-cured tobacco and wheat intercropping and flue-cured tobacco and sweet potato with wheat intercropping was higher in 45 d than the other periods,and the other modes were in 60 d.Chlorine ion content had obvious differences in different modes and periods,Cl content in the growth periods of tobacco showed rising-falling-rising.The soil Cl of flue-cured tobacco and wheat intercropping,flue-cured tobacco and sweet potato with wheat intercropping,maize stubble were gathering in 45 d,and then significantly reduced in 60 d,it indicated thatit is the key period of tobacco absorption of chlorine.The distribution characteristics of soil available sulfur content of topsoil showed 0-10 cm > 10-20 cm > 20-30 cm >30-40 cm,the available sulfur content reached the highest in 60 d of the whole growth period.6.During the field growth period,the content of Cl was highest in 60 d,and then slowly decreased,the distribution of the chlorine content showed upper leaves >middle leaves > lower leaves > stem > root.7.Tobacco agronomic traits and dry matter accumulation in different modes of tobacco with salsa interplanting did not have obviously difference,soil chlorine ion and available sulfur decreased significantly in every period,and the content of soil available potassium improved,tobacco chlorine content and sulfur content reduced,tobacco potassium content increased,the physical characteristics of flue-cured tobacco were improved,smoldering time of tobacco increased,chemical component were more coordination,the chlorine content of tobacco obviously decreased,the content of potassium increased.Addition to the continuous cropping,sensory quality in the other patters improved,economic characters of tobacco had not obvious effect in the modes with salsa. |
