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The study by the tobacco soil salt accumulation and analysis of the main elements in tobacco, basically defined the characteristics of the strength of the major tobacco-growing areas in Hunan soil salinity accumulation, the law, the composition of the salt ions on tobacco growth and the impact of technical measures on the impact of tobacco production, potash types, water run way and straw mulching soil salt accumulation, aims to promote tobacco production is actively prevent tobacco soil salt accumulation or secondary salinization sustainable the development of a scientific basis for effective measures. The main findings are as follows: 1, Hunan tobacco soil salinity table poly serious topsoil amounted 3770.4mg/kg 4526.9mg/kg salt, tobacco harvest, average 4169.5mg/kg, the intensity of salinization of soil; The total amount of salt to each tobacco planting area topsoil Hengyang> Yongzhou, Chenzhou> Autonomous Prefecture. Tobacco soil surface enrichment of salt ions NO 3 - , the SO 4 2 - , Ca < sup> 2 and K , 93.77% of the total amount of salt, and rice - rice crop rotation soil by NO 3 - , the SO 4 2 - , the of Ca 2 and Na ., accounting for 95.16% of the total amount of salt; intensity of salt accumulation in the rotation system, the smoke - rice rotation dryland tobacco> rice - rice rotation. Shonan smoke soil Ca 2 the SO 4 2 - , Cl - , K < / sup> and Mg of 2 and other table gathering appropriate to reduce the levels of Ca, S, Cl, K and Mg in tobacco, the NO 3 - and Na accumulation little effect on the content of the corresponding elements in tobacco; Xiangxi smoke soil Na , SO 4 2 - and Cl - Table gatherings reduce tobacco Na, S and Cl content, while K Mg 2 Ca 2 and the NO 3 - Table Poly has little effect on the content of the corresponding elements in tobacco. The test results show that the correlation between the content of the corresponding element in the salt content of the surface soil and tobacco was not significant (r 0.05 ). 3 enriched surface soil salinity, soil moisture running great. The the water upstream processing the salt content of the surface soil is much higher than the water downstream processing water downstream can effectively reduce the total salt content of the surface soil, and to some extent alleviated the pressure of the soil salt accumulation; moisture downlink salt to the water pressure washed salt, the topsoil salt enrichment strength significantly reduced, the amount of salt and soil seepage water away the salt concentration and salt ions characteristic leaching water main salt ions as K , Ca 2 , SO 4 2 - and NO 3 - . The moisture running on Tobacco biological traits. Potash types also affect soil salt accumulation, potassium sulfate, and potassium nitrate combined application of biological characteristics of flue-cured tobacco in the tobacco field production has little effect on tobacco growth period surface soil salinity ions are K , the of Ca 2 , SO 4 - and the NO 3 - -based, and the the vigorous Na and Mg 2 content is relatively high, these types of ions are likely to accumulate on the soil surface; KNO 3 and K 2 SO 4 be leaching soil flue-cured tobacco yield fertilizer. 5, straw mulching weakened the soil surface evaporation, it is appropriate to reduce the salt content of the surface soil, reduces 1.8% to 22.2% of the salt accumulation. Flue-cured tobacco vigorous growth can accelerate, plant height increased, increased effective number of leaves, leaf area increases, tobacco production and raise output. Straw mulching can enhance the vitality of flue-cured tobacco prosperous long-term roots, increased root volume, so as to promote the absorption of nutrients.
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