Effects Of Fertilization Methods On Alkaline Soil Potassium Absorption Of Tobacco

Potassium is an essential element of tobacco. However, the low Potassium percentage in tobacco is a general situation in China, which seriously affecting the quality of tobacco. And we have not found a proper and effective way to improve the potassium percentage in tobacco. Nevertheless, fertilization could be a way to increase the potassium percentage. It can improve the ability of tobacco plants to absorb potassium, to reduce fixed and loss of potassium in the soil, and thereby increasing potassium percentage of tobacco. This article focuses on the study of three different ways of fertilization:conventional fertilization conventional fertilization +basic improvers application+additional application and conventional fertilization+ whole basic improvers application. This article also researches on the growth and development, the tobacco quality after baking, the dry matter accumulation of tobacco plant’agronomic traits roots, stems,leaves in four major tobacco growing period, as well as the effect of soil pH,available nitrogen、available phosphorus、 rapidly available potassium percentage, potassium utilization rate, and potassium dry matter productivity in four major tobacco growing period. The research results are as follows:1.The effect of regular fertilization and regular fertilization+modifier tobacco processing on tobacco plants’Differences of agronomic traits are not significant. Tobacco plants without fertilization treatments show slow development and potassium deficiency symptoms in maturity.2. Different fertilizer treatments have a significant impact on the chemical composition of tobacco after baking. With regular fertilization+basic and additional improvers application treatment, upper leaves and middle leaves have the highest potassium percentage, which are 2.12% and 2.32% respectively; there is no significant differences of nitrogen base ratio and sugar base ratio for each treatment, which is approximately 0.9 and 0.7 respectively. The results also shows that the potassium percentage in upper leaves and middle leaves are the highest with regular fertilization+ basic and additional application improvers treatment. Also, the nitrogen base ratio and sugar base ratio are relatively reasonable. Those results are also the characteristics of high-quality of tobacco leaves.3. Different fertilization treatments have different effects on the dried weight of tobacco plants in each growth period. Regular fertilization+basic and additional improvers application treatment result in the highest dried weight of tobacco plants. The dried weight of each part of the tobacco plant normally would be root< stem< leaf; The ratio of the dried weight of the underground part and that of the over ground part will first increasing, then decreasing, and finally tend to slow down to a stable level. Different fertilization treatments have little effect the changing trends of the ratio.4. Different fertilization treatments have significant impact on the potassium percentage of different part of tobacco plants in each growing period. The potassium percentage in the roots of tobacco plants keeps decreasing for different fertilization treatments, and there is no significant difference in the potassium percentage value, which are normally in the range of 1% to 4%; the potassium percentage change in stem is similar when applying the regular fertilization +basic and additional application improvers and the regular fertilization+whole basic improvers; after the harvest, from the perspective of potassium percentage of tobacco leaves, the middle leaves has the highest potassium percentage when applying the regular fertilization+ basic and additional improvers application treatment, which is 2.96%; for upper leaves, regular fertilization+ whole basic improvers application will result in the highest potassium percentage, which is 2.35%, and they are all higher than the regular fertilization treatment.5.Different fertilization treatments have significant impact on the potassium accumulation of different part of tobacco plants in each growing period. For the roots, the potassium accumulation first increases sharply, and then decreased; for the stems, the accumulation of potassium keeps increasing; for the leaves, the potassium accumulation first increases, then decreases slowly. The order of different parts of the tobacco plant potassium accumulation level from the highest to the lowest leaf> stem> root. By comparing each treatment, it suggests that the regular fertilization+basic and additional improvers application treatment of tobacco leaves will have the highest potassium accumulation level, which is 4.426g/plant.6.There are some variations in the release patterns in the soil with different fertilization treatment. The available nitrogen and available phosphorus in soil change little. But there is no obvious change of the rapidly available potassium in the soil without fertilization treatment. The rapidly available potassium changes more with the other three treatments. For the tobacco in the period of duration, potassium accumulation level and the rapidly available potassium in the soil are negatively correlated. When the rapidly available potassium in the soil decreasing, the potassium accumulation level of tobacco leaves increasing, but the decrease and increase are not in the same manner; when soil pH is in the range of 6.5-7.8, the potassium accumulation level increases while the PH decreases; when pH is less than 6.5, the potassium accumulation level decreases slowly while the PH decreases, showing some changes with certain pattern.7.The potassium utilization rate and the potassium dry matter productivity of tobacco plants without fertilization treatment are 28.78% and 68.10% higher than the other three fertilization treatments, respectively; in fertilization treatment, potassium utilization rate and the potassium dry matter productivity of tobacco plants are 23.65% and 54.81% higher than that of treatment with improvers added, respectively. Also, the potassium utilization rate(18.21%) and the dry matter productivity (40.80%) of the regular fertilization +basic and additional improvers application treatment are higher than those of regular fertilization+ whole basic improvers application treatment productivity (17.66% and 39.93%,respectively).8.According to the test results, regular fertilization +basic and additional improvers application treatment is the best method to improve the ability of tobacco plants for absorbing potassium. But there is no significant difference with the regular fertilization +whole basic improvers application.