Nutrient Changes of Yellow Soil Successively Planted Flue -cured Tobacco and Its Fertilization Effect

The change of soil nutrients with successive planting and effect of its on growth and nutrient absorption of tobacco plants were studied by collecting and analyzing soil samples in field and pot trial. The results showed that 1)with the successive planting of flue-cured tobacco, the available nutrients in the soil were accumulated yearly under normal fertilization, especially P, S, and K, 2)the concentration of Ca and Mg in tobacco leaves were obviously reduced under applying K fertilizer while the application rates of N and P fertilizers were constant, and that the concentration of K in leaves had the trend of reduction with applying Ca or Mg fertilizer. Applying Mg fertilizer to the soils, with higher P, S, and K, was promoted the growth of flue-cured so that to increase the yields.