The Assessment Of Soil Fertility And Study On Fertilization Technology In Tobacco Area Of Enshi

Through massive sampling and investigation combining with field experiment, this study assessed soil fertility condition for tobacco area of Enshi(burley tobacco and drying tobacco), got the measure of basic fertility character of soil planting tobacco in this area and main obstacle factors influencing tobacco production. At the same time, basing on the experiment and research, this article brought up the main technical measures of fertilization to solve these obstacle factors. The main study results were as follows:1 This study in the main got the measure of basic types of soil planting tobacco in Enshi county, including six soil types and seven subgroups. The main type of soil planting tobacco was yellow-brown soil, and the percentages were 83% of total soil area planting tobacco. The next bests were yellow soil, brown soil, limy soil, Chao soil and rice soil.2 The pH of 70% soil samples were in the range from optimum weak acidic to neutral, the CEC content was medium or more, the soil texture was lighter. The soil fit for producing fine quality tobacco.3 The ability of supplying nitrogen of soil in this area was stronger. The mean of organic matter content could achieve to 28.9g/kg and nitrogen content of base leaching could achieve to 153.9mg/kg. Especially for drying tobacco area, the ability of supplying nitrogen of 70% soil or more was in the level from high to higher.4 The ability of supplying phosphorus and potassium of soil in this area was a little bit lower. The mean of quick-acting phosphorus content was only 13.4mg/kg, about 72% of soil were in shortage or drastic shortage; the mean of quick-acting potassium content was only 158.7mg/kg, about 46% of soil was in the level of low or lower, the condition of lacking in potassium was still severely.5 To the soil conditions, the dring burler area was that produce fine quality tobacco, the ration of nitrogen, phosphorus and potassium was coordinated. But to the drying tobacco area, the ration of nitrogen, phosphorus and potassium was uncoordinated, needed to control nitrogen and increase phosphorus, potassium.6 The soil of planting tobacco was generally lack in magnesium, chloride, boron and zinc. The mean content of changeable magnesium was about 0.5mg/kg, but the ration of...