Panxi Tobacco Planting Area Soil Spatial Variability Of Available P And Its Effects On The Quality Of Tobacco

Soil available P is an important indicator of soil fertility. Soil available P content is subject to natural factors (soil texture, altitude, soil type, etc.) and human factors (cropping, fertilization, irrigation and infrastructure, etc).Most scholars pay more attention to studies of nitrogen and potassium fertilization in flue-cured tobacco rather underestimate the impact of phosphorus fertilizer on the growth and quality of flue-cured tobacco. Currently irrational fertilization practices lead to soil planting tobacco phosphorus deficiency, lack of supply, which affects both improved utilization of nitrogen and potash affect the normal growth of tobacco and tobacco-quality coordination. With the coordination of supply contradictory tobacco planting time is lengthened, Soil available P content and coordinated supply of NPK contradictions become more prominent.Panxi region is the most important tobacco-producing areas in Sichuan Province and the national characteristics of the famous tobacco production base, ensure coordination of soil available P supply is guaranteed the areas of tobacco production capacity, improving quality and increasing the value of important measures. Through the investigation, considering the soil factors, terrain and farming conditions and other information, we have collected 7,408 soil samples and 136 samples of tobacco in Panzhihua and LiangshanPrefecture. By analyzing the test, using method combined by Geostatistics and GIS to study the spatial variability of soil available P and its influencing factors, make correlation analysis on Soil available P and Tobacco Quality, and a clear pattern of spatial variability of soil characteristics and distribution of tobacco-growing areas available P, identify the relevant factors affect available P, draw the correlation between tobacco quality and soil available phosphorus, and make the suggestions of fertilize combined with practical, The results are as follows:(1)Variability of soil available P in Panxi reached 85.72%, the mean reached 18.51mg/kg, the proportion of tobacco planting area was 39.64% greater than 20mg/kg, accounted for 13.78 percent greater than 40mg/kg, but less than 10mg/kg of tobacco planting area also accounted for 34.8%.To Panzhihua, the mean was 16.62mg/kg, the proportion of tobacco planting area was 38.80% greater than 20mg/kg, accounted for 15.15% percent greater than 40mg/kg, less than 10mg/kg of tobacco planting area also accounted for 28.98%. LiangshanPrefecture tobacco planting soil phosphorus content was relatively low, the mean was 16.99mg/kg, the proportion of tobacco planting area was 32.21% greater than 20mg/kg, accounted for 13.56% percent greater than 40mg/kg, less than 10mg/kg of tobacco planting area also accounted for 41.15%.(2)According to the semi-variance fitting model, the available P content in soil planting tobacco in Panxi optimal models are spherical, Nugget coefficient is 88.8%, and the coefficient of Liangshan Prefecture and Panzhihua is 86.7% and 83.6%, belong to the weak spatial correlation, small indicating that soil available P distribution space has small proportion of natural factors in Panxi. From the Step length of available P, Panxi area is 4km, Panzhihua is 25km, Liangshan Prefecture region is 10km; All the determination coefficients were greater than 0.9. On the whole though soil available P content Panxi region has a certain degree of spatial association, but is mainly determined by the random factors (land use, fertilization, tillage practices, cropping systems, etc.)According to spatial distribution map Panxi area, the soil available P content Panxi area into east and west, content of less than 20mg/kg area of more than 50%;Soil available P content of Liangshan Prefecture presented from east to west toward diminishing. Located west of Liangshan Prefecture like Yanyuan Mianning and Xide is significantly higher than other counties, most of them, available P content is more than 20mg/kg, there are even some areas of high levels of phosphorus in the area (> 40mg/kg). Located east of Liangshan Prefecture like Zhaojue Ganluo and Meigu, Soil available P is significantly lower, more than 50% of the area is lower than 10mg/kg; Soil available P content presented in Panzhihua increments from north to south. Located in three regions of Panzhihua size of soil available phosphorus content presented:Miyi>Yanbian>Renhe, the Datian and Dalongtan in Renhe Deshi in Yanbian lack of soil available P content.(3) Influencing Factors:Factors affecting soil available P content Panxi tobacco area, From the point of view of soil types, Yellow soil and new soil phosphorus content is relatively high volume, which is lower in Yellow Brown Earth. From the soil texture, Clay soil available P content in soil is greater than the sandy loam soil;From the view of the extent of soil erosion, The degree of soil erosion and soil available P content has a certain relevance, and a slight erosion of soil phosphorus content is relatively large. The soil available P content in Panxi area increases with altitude; Available P content in the southerly direction is generally greater than northerly direction;Farming conditions: Farmland has no infrastructure has less soil available P content of than infrastructure farmland. This shows that the infrastructure for maintaining soil fertility has a certain role. In some areas of poor conditions, infrastructure for local tobacco production may increase and improve the quality of tobacco has a decisive role. Farmland drainage capability is inversely proportional to the soil content of available P. Judging from the tobacco fields irrigated conditions, We found that Irrigation capability low soil available P content generally greater than the intensity of irrigation capacity.(4)The correlation coefficient Comprehensive analysis of soil available P content and leaf chemical quality is very low, so soil phosphorus content is not the main parameters affecting the quality of tobacco chemistry. Correlation analysis of soil available P content and tobacco corresponding sensory quality indicators can be seen Soil available P content and aroma of tobacco, miscellaneous gas extent, fragrant and sweet temperament sense showed significant negative correlation.