Status Of Soil Nutrients At Differernt Altitudes And Distribution Of Boron Contents In Soil And Tobacco Leaves In Qujing Tobacco-growing Areas

Through a combination of field investigation sampling and analysis of indoor,2390 soil samples of Qujing nine counties in tobacco-growing areas were sampled,and its indicators were tested and analyzed,Qujing tobacco and tobacco soil area divided in five nutrient rating;Take the Qujing nine counties in tobacco-growing areas for example,tobacco district in Qujing calculated fertility five soil samples at different altitudes comprehensive index value (IFI),and this quality tobacco soil fertility of five elevation segments a comprehensive evaluation;At the same time,more systematic study of the city, planting soil boron content of tobacco at different altitudes, and various parts of the tobacco samples after different altitude districts grilled boron content.The main conclusions are as follows:1.Take the 2390 soil samples in Qujing nine counties in tobacco-growing areas as materials, tobacco-growing areas of the Status of Qujing tobacco soil nutrient content were mainly a more systematic study,while the soil samples Qujing Tobacco District 5 altitude segment the main nutrient status were analyzed and comprehensive evaluation, the results showed that:(1)The soil PH of Qujing tobacco growing areas is suitable,with the average level of 6.26;The content of organic matter (35.62g/kg), effective calcium (2518.39 mg/kg) magnesium (341.87 mg/kg), copper (3.92 mg/kg), manganese (57.99 mg/kg) and water-soluble chlorine (30.90 mg/kg) in the soil is extremely rich;The content of Total nitrogen (1.71g/kg), available phosphorus (29.21 mg/kg), effective sulfur (38.79 mg/kg) is rich;The content of Alkaline hydrolysis nitrogen (127.78mg/kg) and available kalium (201.57 mg/kg) is appropriate;The content of total phosphorus (1.29g/kg) effective boron (0.40 mg/kg) tend to be low;The content of total kalium (12.81g/kg) is extremely low.(2) The soil nutrient content in Qujing tobacco growing areas is variationai at different altitude,the soil PH and the content of total nitrogen, total phosphorus, alkali solution nitrogen, rapidly-available potassium, magnesium,effective manganese is at a high level at the altitude of 1300-1500m;When at the altitude of 1500-1700m,the total kalium content is the highest while the organic matter and water soluble chloride is the lowest;At the altitude of 1700-1900m,the content of Water soluble chloride,effective calcium, effective boron is the highest while the total nitrogen, total phosphorus, alkaline hydrolysis nitrogen, effective copper and manganese is the lowest;At the altitude of 1900-2100m,the content of effective sulfur is the highest;At the altitude of 2100-2400m,Organic matter, effective copper is the highest while the soil PH and total potassium, available phosphorus, available potassium, effective calcium, effective magnesium is lowest;Though these datum,we can indicate that the content of soil available phosphorus, water-soluble chloride in different altitude is not significant;The content of Soil total nitrogen, total phosphorus at the altitude of 1300-1500m has a significant difference of 0.05 level compare to other altitude.The content of Organic matter and alkali solution nitrogen at the altitude of 1300-1500m and 2100-2400m also has a significant difference of 0.05 level compare to other altitude;The content of Available potassium and effective sulfur at the altitude of 1300-1500m and 1500-1700m has a significant difference of 0.05 level compare to other altitude;The content of soil total potassium at the altitude of 1500-1700m has a significant difference of 0.05 level compare to other altitude.The content of water soluble chloride is always at a very high level at all altitude.(3)The Integrated fertility index we chosen in the research mainly include the soil pH, organic matter, total nitrogen, total phosphorus, total potassium, alkali solution nitrogen, available phosphorus and available potassium, effective sulfur and effective water-soluble chloride.The Integrated fertility index in Qujing tobacco growing area at the altitude of 1300-1500m、1500-1700m、1700-1900m、1900-2100m、2100-2400m is 0.691、 0.627、0.644、0.753、0.619 separately. 2,Take the Qujing tobacco-growing areas for example, boron content in soil and all partsof the tobacco leaves after roast were tested, the results showed that:(1)The average content of soil available boron is 0.40mg/kg in Qujing, Yunnan Tobacco District, relatively low content Boron content in tobacco leaves are as follows:the averag e boron content of upper leaves is 21.20mg/kg, middle leaves 16.08%, lower leaves 22.68 %.If press the Brazilian import quality tobacco boron content (14.00～31.06mg/kg) standa rd to measure, in Qujing tobacco district,the upper tobacco leaves has 63.45% samples withi n this interval, the middle is 50.29%,and the lower is 46.46%. (2) As the change of altitude, the soil available B content must be changed,the altituderange of 1300～1500m,1500m～1700m,1700-1900m,1900～2400m(Range of components have Significant difference, the altitude range of 1500～1700m,1900-2400m and 1900-2400m have no significant difference.And the content of soil available B is highest levels in the areas of middle altitude(1700～1900m), with the mean of 0.48mg/kg, the content of soil available B is lowest levels in the areas of low altitude(1300-1500m), with the mean of 0.27mg/kg.(3)Among the different altitude grouping,The major difference of the content of boron in different part of tobacco leaf is that:Boron content in upper leaves in the altitude of 1300～ 2100 m will increase as the altitude rise,Between boron content in the upper leaves elevation period witnessed a gradual downward trend,to 2100～2400 m tobacco leaf boron content is slightly higher than before.The highest levels within the range 1300～1500 m above sea level,up to 27.96 mg/kg,Within 1900～2100 m above sea level the lowest, at 19.44 mg/kg.For central leaf boron content, when the altitude is 1500～1700 m, the middle leaf boron content is higher,17.28 mg/kg, when the altitude is 1900～2100 m, central lobe boron content is the lowest, with an average of 15.82 mg/kg.The difference of Central lobe boron content reached a significant level at the altitude of 1300-1900m and 1900-2100m,while group share difference is not obvious.The content of boron in lower leaves is rise with increase in altitude,in 1300-1500m,the content of boron in lower leaves is lowest levels, with the mean of 15.68 mg/kg. in 2100～2400m,the content of boron in lower leaves is highest levels, with the mean of 23.81 mg/kg. The difference of boron content reached a significant level at the altitude of 1300-1500m compared to other altitude. The coefficient of variation of each elevation period of tobacco leaf boron content were signi ficant.(4) By comparing the different soil effective boron content between the content of boron, the results show that, Within the content of soil available B is low, the boron content of tobacco leaf are increased with the increase of soil available B content increased, When the content of soil available B was beyond the scope of the certain, The content of leaves boron rising trend with the increase of available B content is inconsistent.