Plant cultivation in soils heavily contaminated by risk elements is a challenging issue due to phytotoxic effects that restrict plant growth. Liming and phosphate additives application reduce the mobility of some risk elements in contaminated soils and can be a suitable measure for contaminated soils but can also affect availability of nutrients for plants. Therefore, it is necessary to test response of tolerant plants (trees and herbs) on soils heavily contaminated by risk elements and look for the most suitable combination of soil additives and tolerant plants.
Experimental part of PhD thesis was divided into the incubation experiments and the vegetation pot experiments. The incubation experiments: The efficiency of liming and phosphate additives at three application rates was tested for micro- and toxic elements immobilisation in weakly acid and alkaline soils heavily contaminated by As, Cd, Pb, and Zn within period of 42 days. The vegetation pot experiments: The two tolerant plants Salix × smithiana Willd. (three-year experiment) and Rumex obtusifolius L. (one-year experiment) were planted in the same contaminated soils as in the incubation experiments. Both soils were untreated and treated with two doses of lime and dolomite (S. smithiana) or treated with lime and superphosphate (R. obtusifolius). For both plants, we evaluated the initial plant growth, plant mortality, biomass production or content of macro-, micro- and toxic elements in the biomass. We evaluated also the content of organic acids in the biomass of R. obtusifolius.
Higher immobilisation effects on acid-extractable Cd, Zn, Pb, and Mn was observed for fast soluble additives (lime, superphosphate) compare to slow soluble additives (dolomite, rock phosphate) only in weakly acid soil. Lime application irrespective of dose with foliar Fe application and planting willows in the second year after the application of lime seemed to be the most suitable measure for increasing biomass production and decreasing toxic elements, especially Cd and Zn, without decreasing the macro- and micronutrients in the aboveground organs of willows in weakly acid soil. Seedlings of R. obtusifolius are sensitive to high availability of Ca, Cd, Pb, and Zn in soil. Biomass production was negatively related to the mobility of micro- and toxic elements. Elevated transport of micro- and toxic elements from belowground organs into leaves was recorded in both lime-treated soils and in superphosphate-treated alkaline soil as a result of sufficient amount of Ca available from soil solution as well as from superphosphate that can probably modify distribution of micro- and toxic elements in R. obtusifolius as a representative of oxalate plants. Rumex obtusifolius is an As-, Cd-, Pb-, and Zn-excluder and is sensitive to high availability of micro- and toxic elements in the soil. Soil chemical properties affect the distribution of essential elements within the plant greatly. In alkaline soil, R. obtusifolius is an Al-hyperaccumulator with the highest concentrations of oxalate in leaves, of malate in stems, and of citrate in belowground organs. These organic acids form strong complexes with Al that can play a key role in internal Al tolerance.
| Identifer | oai:union.ndltd.org:nusl.cz/oai:invenio.nusl.cz:259628 |
| Date | January 2015 |
| Creators | Vondráčková, Stanislava |
| Contributors | Tlustoš, Pavel, Radim, Radim |
| Publisher | Česká zemědělská univerzita v Praze |
| Source Sets | Czech ETDs |
| Language | Czech |
| Detected Language | English |
| Type | info:eu-repo/semantics/doctoralThesis |
| Rights | info:eu-repo/semantics/restrictedAccess |
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