The Effect Of Gravel And Slope On Planting Tobacco Soil Physical Properties And Growth Of Tobacco

In order to study the effect of gravel and slope on soil physical properties and the growth of Flue-cured Tobacco, we carry out field survey and layout of gravel volume and growth effects of gradient field experiment on soil physical properties and Flue-cured Tobacco in Gulin, Luzhou, Sichuan Province, with four different soil gravel content and four kinds of different slope as the two major factors. To find out the most suitable for the growth of Flue-cured Tobacco in the gravel content and slope conditions. This essay analyses the physical properties of soil, agronomic characters, economic characters and chemical composition etc.. The main research conclusions are as follows:(1) The difference of gravel content and slope has a significant effect on the growth of. GongHe Village has the highest gravel soil average content (34.8%), which is significantly higher than that in other villages(around 10%). The average slope of tobacco in Minle village is the largest (15.4°) and the other villages is around 8°.The overall difference is not significant. Flue-cured Tobacco grows better in high gravel content and slope soil, layering yellowing earlier, appearing orange after baked, which show significantly higher economic characters.(2) The gravel content and soil bulk density have significant negative correlation relationship. Soil bulk density was determined by the applicable to more gravel soil digging method. The average soil bulk density of four kinds of gravel content from low to high are 1.23,1.08,0.92,1.08.Experimental data show that the higher the soil gravel content is, the smaller the soil bulk density is.(3) The high gravel content has a significant role in the regulation of soil moisture and temperature. The soil moisture content in high content of gravel soil in continuous heavy rain weather is 5%-10% lower than that in 5% gravel content. That is the higher gravel content is, the rapidly soil the water content decrease after the rain. The soil water of 5% gravel content under continuous high temperature and dry weather on the third day decreases by 5.4%, while the soil moisture of other high gravel content decreases less than 4%. The soil temperature is always 0.3℃-0.8℃ higher than that of gravel content which is more than 40%. That is the higher the gravel content is, the slower the loss of soil water evaporation and the rising of soil temperature are. Experimental results show that the higher content of gravel soil is, the stronger its water stability temperature ability is, which has a notable effect on the adjustment of soil moisture and temperature.(4) The Flue-cured Tobacco has the best growth and the best productive quality in the soil of which the gravel is accounted for 25%-35%. Therefore, when the Flue-cured Tobacco in this condition, the comprehensive manifestations of the farm characters presented the best state in the period of growth and the mature, and the tobacco leaves have the bigger area, meanwhile, there are a large number of effective leaves. The output (2289.6kg/hm2) is 2.8%-13.8% higher than other gravels content; the output value(44811.4RMB) is 10.5%-28.3% higher than other gravels content; upper-middle tobacco leaves is account for 77.9%,22.2%-36.5% higher than others; the total sugars and reducing sugars of Flue-cured Tobacco content at the peak, and on the contrary, the content of chlorine is the lowest, the total nitrogen content is accounted for 2.34%, which is close to optimal content, the whole flue-cured tobaccos’ chemical content reach the balance. Overall, as the above mentioned, the gravels content remain the 25%-35% is the most proper to plan the Flue-cured Tobacco at the local land.(5) The growth vigor and quality of Flue-cured Tobacco growing at slope of, are the best. The disease of Flue-cured Tobacco is the most serious at slope of 10°, the incidence of the disease is the highest, and the disease of decreases by 5%-10% with the increase of the slope. The agronomic characters of the slope of 10 °nd 20° are the best, the leaf area of Flue-cured Tobacco and the number of effective leaves is higher. The economic characters of Flue-cured Tobacco in 10° treatment is the best. The yield is 2.4%-6.3% higher than other slope treatment, the output value is 2.2%-13.2%higher than other slope treatment and the ratio of middle and upper tobacco leaves is 64.4%,6.8%-19.8%higher than the other slope treatment. Chemical composition of is better than that of grade 5 and chemical composition is better, but the overall difference is not significant. The difference of the comprehensive indexes can be considered that the slope of the field Flue-cured Tobacco is better in the field of 10° and it is also the most suitable slope to plant the local Flue-cured Tobacco.