Effects Of Deep Plowing On Soil Physical And Chemical Properties,Tobacco Leaf Yield And Quality In Rice-growing Tobacco Areas

In order to solve the problem of soil physicochemical and biological properties decline and shallow tillage layer caused by unreasonable farming patterns in Hunan’s rice-growing tobacco areas in recent years,it has led to the decline of soil quality.In-depth research to explore the effects of different depths of deep plowing on the physical and chemical properties of tobacco planting soil and the yield and quality of flue-cured tobacco,to provide a scientific reference for exploring more suitable cultivation techniques and cultivation depths in rice cultivation areas in Hunan.The main research results of this experiment are as follows:(1)In terms of physical properties of the soil,deep plowing 30 cm and 40 cm treatment in powder ridge can significantly reduce soil bulk density(maximum decrease 0.143g/cm3)and increase soil porosity(maximum increase 6.02%)than conventional tillage in 0-40 cm soil layer.Reduce soil compaction(maximum reduction is 276.68 k Pa);powder ridge deep ploughing 40 cm treatment has the lowest soil bulk density(1.317g/cm3),maximum porosity(51.18%),minimum compaction(680.62 k Pa),and improvement of soil physical properties best effect.(2)In terms of soil nutrients,the average pH value of the soil in the experimental field was 7.97.Deep plowing with powder ridges could significantly reduce the soil pH.Among them,deep plowing with 30 mm powder ridges had the best effect on improving the acid and alkali environment of the soil.The pH was reduced to 7.20;It can increase the organic matter content of the soil.The 40 cm deep plowing of the powder ridge in the 20-30 cm soil layer has the most significant effect on the increase of the soil organic matter content(31.48cmol/kg);the 30 cm and 40 cm deep plowing of the powder ridge has a total nitrogen and total phosphorus content of 20 The-30 cm soil layer has a significant lifting effect,which is increased to 1.42cmol/kg,1.64cmol/kg,0.82cmol/kg,and 084cmol/kg,respectively.It has no obvious effect on the total potassium content of the soil.The effects of increasing the content of available phosphorus and available potassium are the most significant,increasing to160.12cmol/kg,35.24cmol/kg,and 421.67cmol/kg,respectively,which can better meet the nutrient requirements of flue-cured tobacco.(3)In terms of the growth and development of flue-cured tobacco,the deep plowing treatment of each powder ridge can significantly improve the plant height,stem circumference and dry matter quality,maximum leaf length,leaf width and leaf area of the tobacco plant at each growth stage,and make the tobacco plant nitrogen-resistant The absorption of element and phosphorus is also significantly improved,of which the treatment effect of 30 cm tillage depth is the best,which is increased to 119.1cm,10.3cm,316.9g,76.0cm,35.8cm and 1727.8cm2 at 75 d after transplanting.(4)In terms of the yield quality of flue-cured tobacco and the yield of the stubble rice,deep plowing can significantly increase the leaf length,leaf width,single leaf weight and thickness of flue-cured tobacco leaves;deep plowing 30 cm can significantly increase the total sugar of flue-cured tobacco leaves,Reducing sugar,total nitrogen,potassium content and chloride ion content,and significantly reduce the nicotine content;the deep ploughing treatment of each ridge increased the yield of flue-cured tobacco and the proportion of first-class tobacco,of which the treatment depth of 30 cm performed best,and the flue-cured tobacco was first-class The maximum proportion of tobacco is 56.17%,and the maximum output value per hectare is 44561.25 yuan;under the deep plowing treatment of rice ridges,the yield of rice in that year has also increased.The yield of 30 cm deep plowing rice has increased by 695.21kg/hm2 compared with conventional tillage.