TDK conference 2011

Measurements were carried out about the nitrate stage from three common Hungarian grass-communities (Agrostio - Phalaridetum; Artemisio santonici - Festucetum pseudovinae; Anthyllido - Festucetum rubrae) in the early summer. We examined the botanical composition of the grass-communities with the conventional quadrate technique, 3-3 soil samples from each field and also plants specimens from the typical species were taken. Some soil parameters (calcium carbonate and organic matter contents, “Arany-sort” number, pH and water binding capacity and soluble nitrate contents) as well as the soluble nitrate contents of the plant samples were measured.

Aims of the investigations were:

 to estimate the nitrate levels of the soil and plants samples of Hungarian grass communities, to find a connection between soil parameters and nitrate levels,

 to search a relationship between plant and soil nitrate concentrations.

 to answer for the questions:

- Are the plant nitrate concentrations poisonous for the animals?

- Is there any new nitrate accumulating plant species?

We determined that:

The nitrate concentrations of the plants show a relatively constant level (35-55 mg NO3-/kg dm.) and it does not depend on the type of the community or the soil nitrate concentrations, if it is among 25-45 mg NO3-/kg dm.)

The soil types and parameters do not have any demonstrable correlation to the plant nitrate level due to the active nitrate reductase system, that can metabolise the absorbed nitrate.

Nitrate accumulating new species were found in our investigations, as Glechoma hederacea (347 mg NO3-/kg) and Mentha aquatica (271,36 mg NO3-/kg). Artemisia santonicum (98,43 mg NO3-/kg), Valeriana officinalis (97,55 mg NO3-/kg), Phalaroides arundinacea (76,24 mg NO3-/kg) and Allium vineale (74,14 mg NO3-/kg) also show a higher concentration of nitrate.

The measured nitrate contents of plants were below the acute toxic level for animals, but some plants exceeded the level of chronic toxicity so we have to take the botanical composition of herbage into the consideration in the case of utilization.