The uptake of As, Cd, Pb, and Zn and potential phytoremediation efficiency of five high biomass producing crops, white sweetclover (Melilotus alba L.), red clover (Trifolium pratense L.), curled mallow (Malva verticillata L.), safflower (Carthamus tinctorius L.) and hemp (Cannabis sativa L.) commonly used as grazing and/or energy crops was evaluated in both pot and field experiments at soils with different level of element contamination. In pot experiment the highest phytoremediation efficiency was demonstrated by C. tinctorius where 4.8% of Cd and 1.1% of Zn were removed from the moderately contaminated soil in one vegetation period when repeated harvest of aboveground biomass was performed. The removal of As and Pb was negligible for all the investigated plant species. At the highest element content in soil inhibition of plant growth due to the element phytotoxicity to plants was reported in most of cases. In the precise field experiment lower phytoremediation efficiency (biennial phytoremediation factors did not exceed 0.2% for Pb and Zn and 0.3% for Cd for C. tinctorius) was determined but yield suppress was not observed. Thus, free space for manipulation with element mobility in soil to increase element uptake by plants remains for further research.

The observations were conducted on chernozem soil in a sugar-beet production region in . Six variants of organic amendment were examined: l -straw harvest, 2 -straw harvest + green manuring, 3 -straw incorporation, 4 -straw incorporation + green manuring, 5 -straw burning, 6 -straw burning till 1977 + intercrop, incorporation of farmyard manure at 10 t/ha since 1978. The effect of organic amendment on winter wheat continuous cropping was statistically significant. On average of the whole period (32 years), the highest yields were produced in variants with straw burning (var. 5) -6.04 t/ha and with green manuring (var. 2) -6.03 t/ha, and lower yields in variants with straw incorporation into soil (var. 3) -5.65 t/ha, (var. 4) -5.67 t/ha. The smallest differences between variants were found in the first decade of the experiment. Over time (in the second and third decades), the differences increased and positive effects of green manuring and straw burning and adverse effects of straw incorporation into soil increased. The yield level of winter wheat continuous cropping was high under the given conditions. The yield for the whole period of the experiment averaged 5.85 t/ha, the yields 5.19, 6.54 and 5.76 t/ha were obtained in the first, second and third decade, respectively.

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In 2008 and 2009, studies made contents of cadmium and lead in the soil and their uptake by non-traditional plants were studied in a small-plot trial. At the same time also the effect of bio-algeen preparations on phytoextraction of heavy metals by these plants was investigated. Experimental plots were established on the reclaimed land after closing down mining operations in the town of Žacléř (North-East Bohemia) where a layer of sewage sludge from a wastewater treatment plant 0.6–0.8 m thick was subsequently applied. The locality is situated in the altitude of 612 m, its average annual temperature is about 6.8 °C and the mean annual precipitations are 857 mm. Analyses revealed higher concentrations of heavy metals in the applied sewage sludge. The average concentrations of lead and cadmium were 180 mg . kg−1 and 6.89 mg . kg−1, respectively. The experiment had two variants: Variant 1 – sewage sludge without any other substances, and Variant 2 – sewage sludge + bio-algeen preparations (B. A. S-90 or B. A. Root Concentrate). To find the most suitable plant species for the phytoextraction of cadmium and lead, the following non-traditional plants were cultivated in both variants: fodder mallow (Malva verticillata L.), rye (Secale cereale L. var. multicaule METZG. ex ALEF.) and white sweet clover (Melilotus alba MEDIC.). The highest accumulation of cadmium and lead in the aboveground biomass was found out in rye, viz 14.89 mg . kg−1 DM and 14.89 mg . kg−1 DM of Cd and Pb, respectively., As compared with other plants under study, white sweet clover exhibited the significantly lowest capability to extract both heavy metals from soil (viz 0.22 and 3.20 mg . kg−1 DM of Cd and Pb, respectively). A positive effect of bio-algeen on phytoextraction of cadmium and lead was evident in all plants. The highest yield of aboveground biomass was recorded on the plot with white sweet clover with added alginate (496 g . m−2). Of plants under study, the fodder mallow seems to be the most suitable crop for the phytoextraction of both metals (0.35 and 5.87 mg . m−2 of Cd and Pb, respectively).

BADALÍKOVÁ, B., HRUBÝ, J.: Following of erosive wash of soil in variants with diff erent intercrops. Acta univ. agric. et silvic. Mendel. Brun., 2010, LVIII, No. 2, pp. 27-34 In a pilot experiment established in a sugar beet growing region the erosive washing away of soil was studied in the years 2006 to 2008. The area is located at an altitude of 246 m with the long-term mean precipitation of 500 mm and the mean annual temperature of 8.4 °C. The soils are classifi ed as Chernozem, moderately heavy, loamy, with a good supply of nutrients, humus content of 2.30 % and an alkaline soil reaction. Slope gradient is 12 %, exposition is NE. To study the role of intercrops in erosion control, three variants were established a er the harvest of the main crop, two variants with diff erent intercrops and one (control) with no intercrop. These were Variant 1 with Secale cereale L. var. multicaule METZG. ex ALEF., a non-freezing intercrop, Variant 2 with cluster mallow (Malva verticillata L.), a freezing intercrop, and a control variant with no intercrop. In Variant 1 Secale cereale L. var. multicaule was desiccated with the herbicide Roundup in early spring. All the variants involved maize as the main crop. In variants 1 and 2, maize was sown in intercrop residues a er seedbed preparation by Vario and a compactor. In Variant 3 maize was sown a er conventional seedbed preparation. For assessment of soil conditions soil samples were taken to determine soil physical and chemical properties and water content in the soil. Soil loss by erosion was determined using specially-designed pockets. Erosive washing away of soil was monitored during the entire growing season of maize. The variants in which intercrops were used were found very eff ective in soil erosion control. In Variant 3 (control) without surface crop residues, the washing away of soil was recorded with each heavy torrential rain. During the all years the total amount of soil loss by erosion in this treatment was 2.25 t . ha −1 . water erosion, intercrops, wash of soil, maize Pro snížení rizika působení eroze je třeba prová-dět protierozní ochranu půdy. Protierozní ochrana je soubor opatření k zeslabení nebo zamezení účinku eroze na půdu, půdní vláhu a povrchovou vodu a pěstované plodiny. Využívá se především v zemědělství, současně však chrání před erozními účinky vodní zdroje, intravilány, komunikace a další stavby, dále pásma hygienické ochrany vodních zdrojů, chráněné přírodní útvary a další. Protierozní účinek se mění vlivem erodovatelnosti půdy. V erodovatelnosti půdy nastávají sezonní změny, které se projevují změnou půdní struktury, stability agregátů a propustnosti půdy (např. Bajracharyar, Lal;1992). Erodovatelnost půdy závisí na více půdních vlastnostech fyzikálního, chemického a mineralogického charakteru, které se dají poměrně snadno změřit (Kinnel, 1993). Rozhodující je stupeň stability půd-ních agregátů pod vlivem energie dopadajících deš-ťových kapek, proto by erozně ohrožená půda neměla zůstat po delší dobu bez vegetačního pokryvu (Kvítek, T...