| Xingwen County,which belongs to Yibin City,Sichuan Province,is one of the main tobacco producing areas of Yibin,and is very suitable for the production of high-quality tobacco with mountain characteristics.Because Xingwen tobacco area is located in karst topography and landform,the topography is severely cut and the cultivated land is scattered,which restricts the modernization and standardized production of Xingwen flue-cured tobacco to a certain extent,so land consolidation of tobacco field is imperative.However,the original soil texture,soil layer structure and tillage layer were destroyed by land consolidation,which resulted in the weakening of fertilizer supply capacity,poor soil structure,easy consolidation and difficult transplantation of tobacco leaves in some tobacco fields.Therefore,this paper mainly studied the application of soil conditioner,green manure planting and overturning,and straw returning to the field to cover three soil improvement measures to plant tobacco after land consolidation.The main results are as follows:1.The effects of different soil regulators on tobacco plant growth period,agronomic traits,dry matter,economic traits,60 days after planting and soil fertility traits after harvesting were studied.The results showed that the growth period of tobacco plants treated with different soil regulators was basically the same,but there was no significant difference.In the early growth stage of Flue-cured tobacco,the growth potential of tobacco plants treated with different soil regulators had little difference,and the accumulation of dry matter in shoot and root had little difference.There was no significant difference among the treatments.The growth of the above-ground dry weight increased greatly after the application of calcium magnesium phosphate fertilizer and potassium humate.The yield and average price of calcium magnesium phosphate fertilizer were the highest,with the output value of 30532.95 yuan/hm~2and the average price of 14.57 yuan/kg.The proportion of middle and upper tobacco was the highest with the application of potassium humate 89.94%.The application of potassium humate,calcium magnesium phosphate fertilizer and lime+water-retaining agent was the highest.Soil fertility is high,and soil fertility affects each other at different times,which can greatly reduce the use of chemical fertilizer.In conclusion,the application of calcium,magnesium,phosphorus and potassium humate is conducive to improving the physical and chemical properties of tobacco-growing soil,improving the speed of recovery of micro-ecological environment of tobacco-growing soil after land consolidation,and improving the yield,quality and economic benefits of tobacco leaves.2.The effects of green manure overturning on mineralization and decomposition of green manure,agronomic characteristics of tobacco plant and field,economic characteristics of flue-cured tobacco leaves,soil pH value,organic matter,bulk density,available nitrogen,available phosphorus,available potassium and biomass and chemical composition of green manure were studied.The results showed that the contents of organic matter,available nitrogen,available phosphorus,available potassium and humus in the soil increased after green manure overturning,while the soil pH value increased.The content of available nitrogen in soil reached 179.8 mg/kg after 60 days of turning green manure,which was 16.2 mg/kg higher than that of the control at the same time;the content of available phosphorus in soil was the highest after 60 days of turning green manure treatment,which was 8 mg/kg higher than that of the control at the same time;the content of available potassium in soil was the highest after 30 days of turning green manure treatment,which was 110 mg/kg higher than that of the control at the same time;the bulk density of soil after turning green manure treatment was lower than that before turning green manure treatment.Turning green manure could increase plant height,leaf length,leaf width,stem circumference and number of leaves retained.The yield and output value of tobacco increased by 5.4%and 7.0%.3.The effects of straw mulching on soil moisture,soil available nitrogen content,root morphology,agronomic and economic characteristics of flue-cured tobacco at maturity stage after land consolidation were studied.The results showed that water retention of straw mulching was lower than that of plastic film mulching;soil available nitrogen content of straw mulching was the highest,soil fertility was improved,and soil available nitrogen content of 0-20 cm layer was the highest.After straw mulching,tobacco plants grew slowly in the early stage,but the root growth was higher than other treatments in the later stage,which improved the yield and quality of tobacco leaves.The yield was 2008.5kg/hm~2and the output value was 40370.85 yuan/hm~2. |
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