Due to continuous single nitrogen fertilization, we hypothesized a built-up deficiency of micronutrients in crops that would limit plant growth and crop quality. In 2-year field experiments using urea-N fertilized grain maize (Zea mays L.), hybrid KWS 2376 at 0, 120 and 240 kg N ha (1 crop uptake of Zn, Mn, Cu and Fe was studied at DC 32, DC 61 and in the grain harvested. Micronutrient contents at DC 32 stage Á 1st node (aboveground phytomass) and DC 61 Á flowering (ear leaf) were all at levels indicative of adequate micronutrient supply to the crop. At both sampling occasions the Fe:Zn and Fe:Mn ratios were adequate implying that Fe did not inhibit the uptake of Zn and Mn. The application of nitrogen increased the Fe content at the 1st sampling in both years; in the second year the same was also the case for the Zn content. Nitrogen nutrition increased the contents of Mn and Fe at the 2nd sampling only in year 2; in the other treatments no changes were observed in the micronutrient contents. Micronutrient correlations in the grain were discovered between Zn and Mn contents and between Fe and Mn contents. In the second year the highest N-rate significantly increased the Fe and Zn content of the grain compared with the lower rates of nitrogen fertilization. Grain yields were not affected by the rate of nitrogen and ranged between 13.65 and 14.34 t ha (1 (1st year) and between 13.68 and 14.18 t ha (1 (2nd year). Nitrogen fertilization did not reduce the content of micronutrients in the plant or grain of maize. It is evident that the continuous single use of N fertilization so far has not resulted in a micronutrient deficiency of the plants limiting the nutrient density of the grain or reducing its quality.

The effects of grass growth and N deposition on the leaching of nutrients from forest soil were studied in a lysimeter experiment performed in the Moravian-Silesian Beskydy Mts. (the Czech Republic). It was assumed that the grass sward formed on sites deforested due to forest decline would improve the soil environment. Lysimeters with growing acidophilous grasses (Calamagrostis arundinacea and C. villosa), common on clear-cut areas, and with unplanted bare forest soil were installed in the deforested area affected by air pollution. Wet bulk deposition of sulphur in SO 2− 4 corresponded to 21.6-40.1 kg ha −1 and nitrogen in NH + 4 and NO − 3 to 8.9-17.4 kg N ha −1 , with a rain water pH of 4.39-4.59 and conductivity of 18.6-36.4 µS cm −1 during the growing seasons 1997-1999. In addition, the lysimeters were treated with 50 kg N ha −1 yr −1 as ammonium nitrate during the 3 years of the experiment. Rapid growth of planted grasses resulted in a very fast formation of both above-and below-ground biomass and a large accumulation of nitrogen in the tissue of growing grasses. The greatest differences in N accumulation in aboveground biomass were observed at the end of the third growing season; in C. villosa and C. arundinacea, respectively, 2.66 and 3.44 g N m −2 after addition of nitrogen and 1.34 and 2.39 g N m −2 in control. Greater amounts of nitrogen were assessed in below-ground plant parts (9.93-12.97 g N m −2 in C. villosa and 4.29-4.39 g N m −2 in C. arundinacea). During the second and third year of experiment, the following effects were the most pronounced: the presence of growing grasses resulted in a decrease of both the acidity and conductivity of lysimetric water and in a lower amount of leached nitrogen, especially of nitrates. Leaching of base cations (Ca 2+ and Mg 2+ ) was two to three times lower than from bare soil without grasses. An excess of labile Al 3+ was substantially eliminated in treatments with grasses. Enhanced N input increased significantly the acidity and losses of nutrients only in unplanted lysimeters. The leaching of N from treatments with grasses (3.9-5.6 kg N ha −1 ) was 31-46% of the amount of N in wet deposition. However, the amount of leached N (4.2-6.0 kg N ha −1 ) after N application was only 7.1-8.9% of total N input. After a short three year period, the features of soil with planted grasses indicated a slight improvement: higher pH values and Ca 2+ and Mg 2+

The aim of this study was to demonstrate the persistence of Mycobacterium avium subsp. paratuberculosis (MAP) in soil and colonization of different plant parts after deliberate exposure to mouflon feces naturally contaminated with different amounts of MAP. Samples of aerial parts of plants, their roots, and the soil below the roots were collected after 15 weeks and examined using IS900 real-time quantitative PCR (qPCR) and cultivation. Although the presence of viable MAP cells was not demonstrated, almost all samples were found to be positive using qPCR. MAP IS900 was not only found in the upper green parts, but also in the roots and soil samples (from 1.00 × 10(0) to 6.43 × 10(3)). The level of soil and plant contamination was influenced mainly by moisture, clay content, and the depth from which the samples were collected, rather than by the initial concentration of MAP in the feces at the beginning of the experiment.

LOŠÁK, T., HLUŠEK, J., JANDÁK, J., FILIPČÍK, R., STRAKOVÁ, M., JANKŮ, Ľ., HUTYROVÁ, H., KNOTOVÁ, D. LOŠÁK, M., ŠEVČÍKOVÁ, M.: The eff ect of soil applications of zeolite, agrisorb and lignite on the chemical composition of clover-grass mixtures grown in arid conditions of South Moravia. Acta univ. agric. et silvic. Mendel. Brun., 2010, LVIII, No. 5, pp. 247-254 The two-year fi eld trial was established in May 2008 on light soil in the cadastre of Ratíškovice near Hodonín in an arid maize-growing production area. Prior to sowing selected soil conditioners were applied in experimental plots of an area of 864 m 2 as follows: zeolite (a mineral of high sorption ca paci ty), lignite (the youngest coal containing humus substances) and the supplementary soil substance agrisorb (polymer organic compound capable of holding in its structure and subsequently releasing water) and they were incorporated into a profi le of 0.15 m. Including the untreated control the experiment involved 4 treatments. The rates of the conditioners were as follows: zeolite -3 l . m −2 , fraction used 1-2 mm; agrisorb -20 g . m −2 ; lignite -1000 g . m −2 . Three types of clover-grass mixtures were sown: landscape mixture with an addition of leguminous plants (seeding rate 200 kg . ha −1 ), regional mixture (100 kg . ha −1 ) and annual mixture (70 kg . ha −1 ). The aboveground biomass taken from an area of 0.05 m 2 was sampled in the stage of bud setting with three repetitions to each treatment. In 2008 and 2009 the respective treatments did not signifi cantly change the contents of N, P, K, Ca and Mg in the aboveground biomass of the clover-grass mixtures. The diff erences in the contents of the macro elements were signifi cant only between the individual types of mixtures and were due to their diff erent botanical composition. Between the years 2008 and 2009 no signifi cant diff erences were discovered among treatments in terms of the contents of P and K in none of the mixtures, but the Mg content decreased in the second year in most treatments by 50 relative % and more. The contents of N and Ca increased signifi cantly in the second year in the regional and landscape mixtures; in the annual mixture also the Ca content. The year-on-year diff erences however were seen also in the untreated control showing the apparent eff ect of the year. A longer period of monitoring is necessary if we are to achieve an objective evaluation of the eff ect of the applied preparations on the chemical composition of the aboveground biomass.

This study provides original data on the impact of human activity on vegetation under the specific conditions of the Kastanozem from the Kostanay region (northern Kazakhstan). Radical changes in land use are provoking deposition in vegetation. The question remains whether natural vegetation will return or whether a different type of vegetation will be created under the specific conditions of the Kastanozems soils. The evaluation of vegetation took place in the fields that were abandoned in different time horizons. Height, cover, biomass weight and species composition of vegetation were monitored. The vegetation of abandoned fields is characterized by low species diversity. Succession runs from annual species to a stage where perennial dicotyledonous species with a deep root system dominate. Spontaneous vegetation leaves a sufficient amount of biomass on the soil surface, which assumes that the land will be protected from undesirable phenomena such as erosion and desertification processes.