Research On Nutrient Status Of Soil And Key Technologies Of Fertilizing In Hechi

Based on the further investigation and comprehensive evaluation of soil fertility status and nutrient elements in tobacco leaves, manuring field trials were conducted. According to the results of manuring field trials, system of balanced fertilization technology that could promote the growth of tobacco plant and improve quality of tobacco leaves was founded. The system could provide technical support for the development of high quality tobacco in Hechi city. The main conclusions were as follows:(1) The average value of soil pH was 6.2(±0.86),and the overall level was the appropriate range. The average content of soil organic matter was 29.1 g·kg-1(±9.9 g·kg-1),and the overall level was appropriate or rich.The average value of cation exchange capacity was 12.4 cmol·kg-1(±4.4 cmolkg-1),and the overall level was appropriate or poor.The overall level of available nitrogen was rich,but the overall level of available phosphorus and potassium was less and precious little. The overall level of exchangeable calcium and available sulfur was appropriate,but the overall level of exchangeable magnesium was poor. The overall level of available zinc, molybdenum, Manganese and chloride. The overall level of available iron was rich,but the level of available boron was poor.(2) compared to tobacco leaves of other tobacco planting areas,the content of nitrogen and phosphorus in Hechi tobacco leaf was less than other tobacco planting areas. The content of potassium was more than other tobacco planting areas,but less than high quality tobacco leaves. The content of calcium was rich,but the content of magnesium was poor. The content of sulfur and chlorine was in medium level,but the content of manganese and boron was serious less than other tobacco planting areas.(3) The effect on tobacco growth and tobacco quality of different fertilizer(nitrogen fertilizer, phosphorus fertilizer and potassium fertilizer) amounts was studied. The results showed that the amounts of 6kg/667m2,11kg/667m2 and 24kg/667m2 in nitrogen fertilizer, phosphorus fertilizer and potassium fertilizer was best fertilization way. fertilization ways(4) Based on the same level of nitrogen, phosphorus and potassium fertilization,the effect on tobacco growth and tobacco quality of different amounts of organic fertilizer was studied.The results showed that the amount of 20kg/667m2 was best fertilization way.(5) Pointing at the condition that the content of available potassium was generally low, the effect on tobacco growth and tobacco quality of different amounts of biological potassium fertilizer was studied. The results showed that conventional fertilization and Increasing application 2kg/667m2 of biological potassium fertilizer was best fertilization way, reducing the 10%amount of conventional fertilization and Increasing application of 2kg/667m2 was also suitable.(6) Based on the same level of nitrogen, phosphorus and potassium fertilization, the effect on tobacco growth and tobacco quality of different fertilization time was studied.The results showed that potassium application at rasette stage(50%) and topping stage (50%) was best fertilization way.(7) Pointing at the condition that the content of exchangeable magnesium and soil pH was low, the effect on tobacco growth and tobacco quality of different amounts of dolomite lime was studied. The results showed that the amount of 100-150kg/667m2 was best fertilization way when the value of soil pH was about 5.0.(8) Pointing at the condition that the content of available boron was low, the effect on tobacco growth and tobacco quality of different methods of borax was studied. The results showed that conventional fertilization and Increasing application 2kg/667m2 or spraying 0.15% of borax was best fertilization way.Based on the above results, the general idea of balanced fertilization technology should stabilize the amounts of nitrogen fertilizer, increas the amounts of phosphorus, potassium, magnesium and boron fertilizer. In order to improve potassium application mode and efficiency of potassium fertilizer,biological potassium fertilizer should be applied and application time of potassium fertilizer should be delayed.