Seasonal dynamics of dandelions (Taraxacum officinale L.) in permanent grassland

摘要

The objectives of our research were to study the variation of dandelion (Taraxacum officinale L.) in a long-term pasture. Dandelions had very favourable background conditions to spread since they also dominated beyond the borders of the experiment. The experimental data, covering 11 years, show that the amount of dandelions in the pasture had been almost consistently decreasing from the first year up to the ninth year of use. During the growing season the amount of dandelions in the sward varied significantly. The highest content of dandelions was found in the dry matter yield of the first grazing, while the smallest content in that of the second grazing. Liming and fertilization decreased the amount of dandelions. The occurrence of dandelions was positively affected by soil pH, with fewer dandelions in the soil with a pH_(KCI) of 6.6-7.0 than with a pH_(KCI) of 5.1-5.5. Soil pH and fertilization caused no significant effect on the content of potassium in dandelions. The lowest concentration of potassium was estimated in the second grazing at the background fertilization of N_0P_(60)K_(60).