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Long-term field experiments conducted under different soil and climate conditions and their databases provide invaluable information and are indispensable means in the study of the productivity and sustainability of the soil management systems. We evaluated the results of the dry matter yields of the main products obtained with four variants of organic and mineral fertilisation in three long-term field experiments established in 1955. The experiments differed in the cultivated crops. The period of evaluation was 12 and 16 years (1985-2000), respectively. The productivity of nine-year crop rotation was lower with the fertilised variants than that with the alternative growing of spring wheat and sugar beets. The dry matter yields on the Nil variants, however, were higher in the crop rotation than in the alternate sugar beet and spring wheat growing, apparently due to the symbiotic nitrogen fixation. The dry matter yields of sugar beet and mainly of spring wheat declined in almost all variants of fertilisation in the alternate sugar beet and spring wheat growing, over the evaluated time period. In spite of the relatively high dry matter production, the declining yields indicated a lower sustainability of the alternate cropping system. Both organic and mineral fertilisation increased the production of the cultivated crops. The differences in the average dry matter yields were statistically significant. Both organic and mineral fertilisation enhanced significantly the N-uptake by the cultivated crops. The effectivity of nitrogen input was the highest with the alternate cropping of sugar beet and spring wheat indicating that it was more demanding for the external N-input and thus less sustainable than nine-year crop rotation.

The level of the usage of information and communication technologies (ICT) has a direct influence on the development and competitiveness of individuals, firms, production sectors, regions and even the whole continents. The availability of ICT, including the Internet, to agricultural enterprises in theCzechRepublicis already very satisfactory. Due to the structure of agricultural enterprises the penetration of Internet technologies in theCzechRepublicis more intensive than in most EU countries. Therefore an urgent issue is the level of the usage of these technologies that is not an issue related to finances anymore but it is a problem related to the knowledge and habits of users and availability of information and services. The project of the portal for the agriculture sector and countryside AGRIS has a significant impact on the level of the usage of Internet information and services in the agriculture sector.

Problems concerning total dry weight and distribution of underground phytomass were studied in a pasture trial at Rapotin near Šumperk, the CzechRepublicin the period 1995-1999. The total weight of dry underground pasture phytomass (DUP) was 976 g/m² (5-year average) in a soil layer of 0-200 mm (both live and dead roots). The DUP was significantly increased by mineral fertilizers (90 kg N/ha, 30 kg P/ha a 90 kg K/ha). The weight of DUP was not significantly influenced by a grazing system, renewal or resowing of the original grassland. In unfertilized plots, DUP weight amounted to 989 g/m², i.e. 92 g/m² (8.6%) less than in fertilized plots in the period 1996-1999. In the same period, under the grassland exploited by rotational grazing 1142 and under continuous grazing 1082 g/m² DUP were determined, i.e. by 60 g/m² (5.5%) less. The highest DUP weight in the period 1996-1999 was found in autumn 1997 (1222 g/m2) immediately before achieving the maximum forage yield in May 1998. In a layer of 0-20 mm, 54.6% of the total DUP was found. In this surface layer, significant increase in the DUP weight was found in fertilized plots. In 1999, some 88.5 and 90.2% of DUP were concentrated in unfertilized (903 g/m²) and fertilized (952 g/m²) plots, respectively in a layer of 0-100 mm.

Biochemical variability between thirteen European and five Czech potato (Solanum tuberosum L.) cultivars grown in theCzechRepublic was studied by soluble protein, isoesterase, and isoperoxidase electrophoretic patterns. It was confirmed that cultivar differences in protein polymorphism can be revealed by applied electrophoretic patterns. It was shown that the different character of protein and isozyme profiles required different approaches to their evaluation. For complex patterns such as electrophoretic soluble protein spectra, it is more convenient to use the evaluation of their absorbance profiles and for simpler profiles of isozymes the evaluation based on the presence or absence of a band in a definite position (simple matching) should be used. In spite of the complexity of tetraploid disposition of analysed cultivars, the results suggested higher similarity of profiles between relative cultivars and they also indicated the existence of higher similarity between cultivars from the same breeding firm.

The yield potential, quality and level of resistance to powdery mildew (Erysiphe pisi DC.) of afila smooth seeded pea (Pisum sativum L.) were tested in the field trials. The cultivars and breeding lines Mozart, Consort-R, AGT-01, Cebeco 1171 and AGT-GH surpassed the control cv. Gotik in the yields of dry seed, in contrast the dry seed yields of Highlight, AGT-KR, Melfort and LU 390-R2 were about 12-27% lower than that of the control. The low seed yield was caused by virus infections (PEMV, BYMV), root diseases (Pythium, Fusarium), and a low level of thousand seeds weight (TSW). Material crossing with donors possessing high yield potential, a higher TSW, and a higher tolerance to root diseases had a positive effect on the dry seed yield. The main objective of the resistant pea breeding programme is afila smooth seeded pea resistant to powdery mildew, with a high tolerance to viruses, root diseases, and lodging, with the stem length of 60 to75 cm, and with high yield potential.

The observations were conducted on chernozem soil in a sugar-beet production region in 1971-2002. 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.

Four protein fractions: 1 - albumins and globulins, 2 - gliadins, 3 - glutenins (extracted in NaOH), 4 - glutenins (extracted in SDS) separated by SDS-PAGE were used as biochemical markers for evaluation of polymorphism level in three spelt wheat cultivars - Hercule, Altgold and Rouquin, three new-breeders' spelt lines - H92.27, H92.28 and M92.20 (originated from hybridisation between spelt and common wheat) and reference common wheat cultivar Brea. Electrophoretic phenotypes and zymograms were evaluated by means of digital image analysis and Nei and Li coefficient of similarity was used to evaluate the relation of analysed genotypes. Entire evaluation of all four-marker systems showed differences between common wheat cultivarBreaand spelt cultivars and spelt breeders' lines. Also significant differences between old spelt cultivars (Hercule, Altgold and Rouquin) and new spelt breeders' lines were found. The reality of the mutual passing of protein fractions (gliadins and glutenins), based on Osborne extraction was confirmed. In this sense it is necessary to see both fractions as dynamic overlapping structures.

The Cd and Zn accumulation and phytoextraction potential of seven willow clones was investigated in a pot experiment for two vegetation periods. Heavily polluted Fluvisol-Litavka, moderately contaminated Cambisol-Pribram, and unpolluted control Chernozem-Suchdol were used. Significant differences were found in Cd and Zn accumulation between the willow clones. Cd and Zn were transferred from roots to aboveground tissues and all tested clones confirmed higher Cd and Zn accumulation in leaves than in twigs. Cd and Zn amounts removed by willow leaves were the highest from the most polluted soil (up to 83% Cd and 71% Zn of total removal). Therefore the harvest of leaves is necessary if willows are planted for heavy metal phytoextraction. Although the extremely high Zn contamination of Fluvisol-Litavka significantly reduced biomass production, willows planted in this soil showed the highest Zn removal because of extremely high Zn accumulation (max. 5061 ppm in leaves). Clones planted in moderately contaminated soil achieved the highest Cd removal. Clones showed different abilities to remove Cd and Zn, which was dependent on soil type and contamination level. Remediation factors were determined less than 1% for Zn in the heavily polluted soil and also unsatisfactory for Cd. However, it was shown that willows were suitable phytoextractors of moderately contaminated soil. About 20% of Cd and 4% of Zn were removed by harvested biomass from the total content of soil after two vegetation periods.

A survey was made to evaluate sanitary status of grapevines in the Czech Republic with regard to occurrence of economically important viruses. Propagation material of 109 grapevine clones was tested for presence of Grapevine fanleaf virus, Arabis mosaic virus, Grapevine leafroll-associated virus 1, Grapevine leafroll-associated virus 3, Grapevine virus A, Grapevine virus B and Grapevine fleck virus. Dormant canes were collected and cortical scrappings were analyzed by DAS-ELISA. All seven viruses tested were found to be widely spread in Czech propagation material of grapevine. From 330 individual vines tested, 148 vines were found to be infected with at least one virus. From 109 clones tested, in 98 clones at least one vine negative for tested pathogens was found. Such vines were promoted as candidate plants into screenhouse in Faculty of Horticulture Lednice and will be further tested by other methods. Sanitation of infected grapevine clones is needed in near future.

Results of scoring the resistance of 35 selected spring barley varieties to powdery mildew, exhibiting high powdery mildew severity, in 307 variety trials of the Central Institute for Supervising and Testing in Agriculture were analysed. The varieties can be divided into two groups: the varieties that could not induce any changes in the pathogen population (the varieties with no effective resistance gene and varieties carrying gene mlo) and the varieties possessing major resistance genes [a total of 12 Ml-genes: a1, a3, a6, a7, a9, a12, a13, at, k1, La, g and (Kr)] to which the pathogen population adapted in 1971-2000. The time slope of decreasing resistance of varieties is described. The importance of individual evolutionary forces (mutations, migration, direct selection, indirect selection and recombinations) for the erosion of efficiency of respective major resistance genes and the effects of pathogen adaptation on population complexity and diversity are discussed.

The objective of this study was an improvement on oat identification procedure for laboratory applications, and the comparison of albumin-globulin and avenin protein patterns in five hulled and naked oat cultivars: Abel (CZ) and Izák (CZ) - naked oats, Auron (CZ), Edmund (D) and Expander (D) - hulled oats. The last object of this study was the authenticity verification of standardly prepared meal samples with various proportions of admixture. It was confirmed that avenins, characterised under SDS-PAGE conditions, are reliable implements for the identification of oat cultivars. It was found that oat grain contains, on the basis of Osborne fractionation, another significant protein fraction - glutelins. The question of the protein fraction analysis that was used for the admixture identification stays still open. In sufficiently different cultivars, the certainty of the admixture detection in meal samples may be high. Nevertheless, in other cases (higher cultivar similarity) it will be necessary to use some other, more sensitive techniques.

In the present paper genetic relationships of twenty varieties of cashew are described on the basis of morphological characters and RAPD (Randomly Amplified Polymorphic DNA) markers. Results obtained for the phenotypic characters based on similarity coefficient were divided into four clusters with 70% similarity. By means of similarity coefficients (SG), cluster I was found to consist of twelve varieties. Cluster II consisted of a single variety, NRCC-1, cluster III consisted of six varieties and cluster IV had only one variety, Vridhachalam-2. The analysis started by using RAPD markers that allowed us to distinguish 20 varieties. A total of 80 distinct DNA fragments ranging from 0.2 to 3.0 kb were amplified by using 11 selected random 10-mer primers. Genetic similarity analysis was conducted for the presence or absence of bands in the RAPD profile. Cluster analysis clearly showed that 20 varieties of cashew grouped into two major clusters based on similarity indices. The first major cluster comprised one minor cluster. The other major cluster was divided into two sub-minor clusters, one sub-minor cluster having three varieties and the other sub-minor cluster was represented by 15 varieties. Among the 20 varieties, Ullal-3 and Dhana (H-1608) showed the highest similarity indices (87%). It was noted that Vengurla-2 and Vengurla-3 were not grouped into a single cluster but Vengurla-4 has 82% similarity to Vengurla-3. The variety Vengurla-2 has very close similarity (85%) with variety Vridhachalam-3 (M-26/2). The analysis of genetic relationships in cashew using morphological traits and RAPD banding data can be useful for plant improvement, descriptions of new varieties and also for assessment of variety purity in plant certification programmes.

Development of powdery mildew and leaf rust epidemics was examined on three winter wheat cultivars with different predispositions to powdery mildew in three-year experiments. The progress of powdery mildew and leaf rust on the same cultivar was conditioned by its dissimilar susceptibility to the respective disease. Fit temperature played an important role at the beginning of the particular disease and during its progress. Significant differences in the disease severity of powdery mildew and leaf rust were recorded on single leaves. Disease severity of leaf rust was higher on upper leaves while disease severity of powdery mildew was higher on lower leaves.

The genetic diversity and the relationships among rapeseed germplasm, including a collection of 20 Chinese, 25 Czech, 2 German, 2 French, and 1 English cultivars and breeding materials were evaluated using random amplified polymorphic DNA (RAPD) markers. A total of 79 different polymorphic amplification products were obtained using10 selected decamer primers. RAPDs revealed a significant level of polymorphism among the accessions. The diversity index (DI) ranged from 1.390 to 3.491, showing a sufficient potential of selected primers to differentiate among studied genotypes. Three different metrics were used to assess genetic diversity. The best fit between a priori knowledge about germplasm origin and a posteriori grouping was found using Hamman metrics. Cluster analysis based on Hamman pairwise distance comparison divided the studied accessions into three main clusters. The first group included only accessions fromChina, the second group only that fromEurope with the exception of Zhongshuang No. 2, a Chinese winter rape possessing European cultivars in the pedigree. The third group included accessions both fromChina andEurope. The results indicate the occurrence of a considerable genetic variation between Chinese and European accessions.

Dependently on planting conditions caraway fruits contain 1-9% of essential oils consisting of about 30 compounds. Carvone and limonene account for the main portion, about 95%. To evaluate the quality of various registered caraway (Carum carvi L.) cultivars (Kepron, Prochan and Rekord) planted during 1998-2000, regarding the effect of sample grinding and preparation, plant treatment and time of harvest, the amounts of essential oil and the carvone/limonene ratio were determined. Both whole and ground caraway seeds were extracted. As obvious from the results, SFE is not suitable for the determination of essential oils in whole seeds since the results are lower in comparison with those of ground caraway. The way of grinding was also examined. Of the three mills used, a splintery mill VIPO seemed to be the most suitable. Further, the amount of essential oil was studied in caraway gathered at the beginning of maturation (sample A) and at full ripeness (sample B) of caraway seeds. It was found that the samples gathered at full ripeness (samples B) had more essential oil. It was also concluded that the use of the regulator Roundup Bioaktiv during caraway maturation to unite the ripening of achenes in the main umbel and the first-order umbels, and the use of fungicides (Alert S and Prelude 10) affected positively the amount of essential oil in caraway. Possibilities of SFE application for the essential oil determination in small samples gathered during breeding were investigated. The results were used as a one of the criteria during breeding. Classical way of the essential oil determination does not allow this option. An alternative method for the isolation and determination of essential oils - supercritical fluid extraction (SFE) - was investigated in this study.

Zinc distribution in the main soil fractions and zinc accumulation in potatoes, maize, wheat and barley after different soil treatments (basic sludge rate, triple sludge rate, NPK, NPK + inorganic Zn) were investigated in a field experiment conducted at five localities of the Czech Republic (Červený Újezd, Hněvčeves, Humpolec, Lukavec, Suchdol) with different soil and climatic conditions. Three soil types were investigated in the experiment: clay-loamy Chernozems, loamy Luvisols, clay-loamy Luvisols and two loamy Cambisols. Sequential analyses provided an overview of soil Zn distribution in the following fractions: exchangeable, Fe-Mn oxide, organic and residual ones. The sludge and inorganic Zn addition supported Zn mobility growth and higher Zn retention in Fe-Mn oxides in all tested soils. The influence of the above-mentioned treatments on higher Zn association with soil organic compounds was not explicitly found. Potatoes, wheat and barley accumulated more Zn after its addition into the soils by sludge and inorganic salt. By contrast, Zn content in maize decreased with higher input of Zn into the soil. The highest Zn concentrations were usually observed in plants grown on both Cambisols.

In the experiment conducted in the greenhouse, the different doses of UV-B radiation applied to the two species Avena fatua and Setaria viridis induced changes in leaf and plant morphology. It was a decrease of plant height, fresh mass of leaves, shoots and roots as well as leaf area. Besides, it caused the leaf curling in both of the species. The significant differences between Avena fatua and Setaria viridis in the studied traits were mainly due to the tillering ability of the species. The content of chlorophyll varied considerably. The average values of leaf greenness (SPAD units) for oats were about 43 while for green foxtail 32, respectively. U-VB did not reduce leaf weight ratio, shoot dry matter, shoot to root ratio and leaf area ratio.

The phosphorus (P) availability was tested on hydromorphic soils located in theSavavalley. 480 soil profiles covering the area of31 227 hawas analysed in our study. The plant available P was determined by the Ammonium-Lactate method. The P availability in the surface layer (0-30 cm) is very low (up to 5 mg P2O5/100 g of soil) in about 30% of the tested agricultural land (9 440 ha), next 32% (9 897 ha) is in the range of a low P availability (from 5.1 to 10 mg), while only 17% (5 445 ha) has a good or very good P availability (above 20 mg). Especially high frequency of low P availability was found in vertic gley, amphygley and hypogley soils (total8 680 haor 28% of tested agricultural land).

The main goal of this work was to calibrate and evaluate the CERES-Barley and CERES-Wheat crop models. The experimental fields used for the model evaluation are situated in three different production regions (maize, sugar beet and potato main growing regions, respectively) with altitudes of 179, 204 and 560 meters above the sea level. Grain yield and date of anthesis together with maturity dates served as reference for the model evaluation. Two evaluation approaches were tested in this study. The first one uses historical data series and it is based on long-term field experiments with capability to reflect interannual weather variability. The second approach uses results of one-year multiple treatment experiment. The model evaluation is then based on a set of treatments differing e.g. in sowing date or an amount of used nitrogen fertilizer. Grain yields simulated by both models are acceptable when compared with experimental results: the coefficient of determination for historical series varied from 0.69 to 0.86 for evaluation of CERES-Barley at the three examined sites and reached values of 0.60 and 0.86 for the CERES-Wheat model at two experimental sites. The lower coefficient of determination of the wheat model was recorded at the locality with the highest altitude and coldest winter conditions. There, also the worst reliability of simulated phenological development was noted. At the second locality where the CERES-Wheat model was tested and at all three localities where CERES-Barley was applied, the simulated duration of vegetation period and anthesis dates were relatively accurate and yielded strong statistical correlation. The one-year multiple treatment experiment proved to be useful to determine the models sensitivity to differences in crop management. The combination of both approaches seems to be the best solution for evaluation of similar crop models if the detail long term experimental data are not available.

Both spring and winter barley were sown after a forecrop of winter rape. Three registered model varieties of six row and two row winter barley reached in the period 1999-2001 significantly higher yield than three model varieties of spring barley. Two row spring and winter varieties produced significantly higher thousand grain weight (TGW) than six row winter barley. The resistance to diseases and lodging (correlation coefficient with resistance to powdery mildew represent 0.68**, rust 0.72*, lodging 0.61**) was the most important factor determining the yield. Resistance to rust has influenced sieving on 2.5 mm, correlation coefficient reached value 0.88**. No significant differences were determined in any malting quality parameter when varieties of two row winter barley variety (Tiffany), and spring barley varieties (Akcent and Tolar) were compared. Variety Tolar reached higher parameters for friability and a beta glucan content. Between years, significant differences were found in following parameters: protein content and apparent degree of attenuation. Due to reduction of area sown with spring barley and reduced yield potential, two row winter barley varieties with comparable malting parameters are recommended to be cultivated as the reserve crop for malting barley industry demands.

The research objective was to investigate the influence of different pipe drainage systems on the concentration and quantity of atrazine leached in drainage water, as well as in surface (0-30 cm) and sub-surface (30-60 cm) soil horizons in the production of agricultural crops on drained Gleyic Podzoluvisol. Investigations involved four different variants of drainpipe spacing (15, 20, 25 and 30 m, i.e. four variants in four repetitions). In a particular trial year, the same crop was grown and the same agricultural practices applied in all trial variants. Maize was grown in the first two trial years and wheat in the last year. Soil and water samples were qualitatively and quantitatively analysed for the presence of atrazine by gas chromatography. Atrazine concentrations in drainage water ranged from those within the limits tolerated for drinking water (out of the growing season) up to 458 ng.dm^-3. Maximum quantity of leached atrazine was recorded in 1998 (0.500 g.ha^-1), namely, from atrazine application in May 1997 to March 1998 incl., 0.630 g.ha^-1 or 0.052% of the initially added quantity was leached. Maximum atrazine concentration in the surface soil layer was recorded in traces or it was not recorded at all (0.013 mg.kg^-1), whereas no atrazine was recorded in the subsurface layer during the trial period. Analysis of variance produced no statistically significant difference in the atrazine concentration and leaching in drainage water and in the surface soil layer between different variants of pipe drainpipe spacing.

This paper deals with the changes in soil active acidity, mobile aluminium, base saturation, iron and manganese under the influence of quicklime (QL), mixture of soft lithothamnian limestone (SLL) and dolomite (D), and special natural amendments (SNA) based on zeolite tuff. Investigations were carried out on pseudogley of mesoelevations, dystric. The four-year trial was set up according to the Latin rectangle method with 18 trial treatments in four replications. While SNA based on zeolite tuff had little effect on changes of the studied parameters, traditional lime materials (LM), owing also to the fact that they were applied at several times higher rates, had a very positive effect. Soil acidity, iron and manganese were reduced under their influence, mobile aluminium, particularly under their higher rate, was fully blocked or reduced within tolerable limits, and base saturation was raised to a satisfactory level. Effects of SNA depended on the ratio of zeolite tuff and the lime component in them. It could be presupposed that their main efficiency happened in the domain of ion exchange with a positive impact on soil fertility.

Water regimes of extensively used grasslands (one cut per year, two cuts per year, no cut, mulching) were determined and compared by drainage lysimeters in 1998-2000. Although the botanical composition and yields of experimental swards were different, there was no statistically significant difference in their water regime (only the soil moisture content of no-cut variant was significantly higher than in other variants). A determinant factor for the water regime of grasslands (GR) is the sum of rainfall over the growing season while the GR water regime is influenced by land use immediately after the cut. Water runoff from the soil profile 0.0-0.60 m (water supply to the groundwater level) was found to be negligible in the growing season, a substantial groundwater recharge occurs in an off-season period and/or at the beginning of growing season. Mulching was not proved to reduce evaporation. The best type of management providing for the economical water regime appears to be a one-cut variant. Relationships between botanical composition and GR water regime are also described.

In field trials in 1998-2000, ten varieties of the world collection of birdsfoot trefoil (Lotus corniculatus) were evaluated for herbage and hay yields. In all the years of testing yields from three cuttings and total annual production were evaluated. In 1999, seed yield was also recorded. As a control, alfalfa (Medicago sativa) variety was included in the experiment. The test varieties showed good productivity in the first and especially in the second year of testing, most of them exceeded alfalfa in herbage yield in individual cuttings and in total productions. As for hay yield, the differences were not so great. Local varieties showed very good productivity, predominantly in herbage yields. Of foreign varieties, the best herbage, hay and seed yielder was the Hungarian variety Puszta. There were no statistical differences in seed yield between the varieties. The yields were, however, relatively low.

High yielding varieties of rice (Oryza sativa) cultivars were tested for their tolerance to different levels of molybdenum (Mo) (0.1µM - control, 0.2, 0.4, 0.8 and 1.6µM) in nutrient solution at pH 6.8. Seeds of rice were germinated and grown in presence of molybdenum under controlled environmental conditions. Standard growth parameters such as root length, shoot length, root/shoot dry biomass and root/shoot tolerance index were tested as markers of molybdenum toxicity. Measurements as early as 48 hours after the germination did not yield consistent results. However, root measurement on 3^rd, 6^th and 9^th day after root emergence showed significant differences among cultivars of rice. Rice cultivars Annapurna, Kusuma, Deepa and Vaghari developed better root system while, Paridhan-1, Pusa-2-21 and Ratna showed poor growth of the roots in presence (0.8µM) of molybdenum. The root tolerance index (RTI) and the shoot tolerance index (STI) in Annapurna, Kusuma and Deepa in rice were high indicating their tolerance to molybdenum; Paridhan-1 and Ratna, however, showed low RTI and STI. Based on the growth parameters, twenty cultivars of rice were ranked in respect of their tolerance to molybdenum: Annapurrna > Deepa > Kusuma > Vaghari > Hamsa > Vikram > Bharati > Paridhan-2 > Aswathi > Subhadra > Sankar > Sakti > Nilgiri > Rudra > Hema > Pragati > Pusa-2-21 > Ratna > Paridhan-1, respectively. Molybdenum toxicity was correlated with increased peroxidase and catalase activity in different cultivars of rice. This method can be employed for quick screening of rice cultivars for molybdenum tolerance in breeding programmes.

A pot experiment was conducted in order to examine the influence of soil contamination with diesel oil at 0.0, 2.4, 4.8 and 7.2 ml/kg on the activity of dehydrogenases, urease, acid phosphatase and alkaline phosphatase. The results indicated that diesel oil contamination of soil strongly inhibited the activity of dehydrogenases and soil urease, but had only a slight effect on the activity of acid phosphatase and alkaline phosphatase. The negative influence of diesel oil on the activity of dehydrogenases and urease was attenuated by soil inoculation with Streptomyces intermedius spores. The potential biochemical index of soil fertility computed from the soil enzymatic activity and carbon content was negatively correlated with diesel oil contamination and positively correlated with crop yield. Biochemical properties of soil were improved by oat cultivation.

The monitoring was carried on in the years 1996-2000 in the polyfactorial P-A field trial in Lukavec, Pelhřimov district. The given locality is characterized by low fertility sandy-loamy cambisoils, by long-term average annual rainfall of 653 mm, by average annual temperature of 7°C and its altitude is 620 m. The field trial included different organic fertilizations; graduate N-doses, different soil tillage as well as different forecrops. It manifested in this group of field trials that the forecrop value of red clover and dung manured potatoes before winter wheat was practically the same in the given locality. The optimal N dose for potato yields was about 80 kg N.ha^-1. In oats the yields after red clover with using the Horsch system in spring were significantly lower than after embedding of red clover in autumn. In cereals, graduated N doses increased the numbers of ears (panicles) per m2, but the mass of 1000 grains often decreased. In addition, N content in grain and straw increased with N doses, while pH annually decreased by 0.1 to 0.4.

In the period 1996-1999 field trial was performed in Obory near Kwidzyn on heavy textured Fluvisols. The experiment was aimed to determine yield, chemical composition, heat value of wood of six genotypes of willow coppice in relation to cutting frequency and on determining the costs and profitability of willow production on arable land for purposes of energy generation. Yield of wood dry matter in one-year cutting cycle amounted to 14.09 t/ha/year 1 and significantly increased to 16.05 and 21.55 t/ha/year when harvesting was performed in two and three years cycle, respectively. The highest yield was found for Salix viminalis 082 form cut in three years cycle and it amounted to 26.44 t/ha/year 1. Stems of Salix sp. cut every three years showed the lowest water content (46.05%), high heat value 19.56 MJ/kg dry matter and the highest content of cellulose (55.94%), lignins (13.79%) and hemicelluloses (13.96%). High yielding potential of Salix sp. and high content of cellulose and lignin in wood make this crop very prosperous as a feedstock for bioenergy production. The highest profit from the willow plantation was obtained in case of harvest every three years at 578.76 EUR/ha/year.

The efficiency of the application of organic and inorganic additives on the reduction of mobility and transfer of As, Cd, Pb and Zn from the soil into the plants was observed. The dung, compost, acid peat and muck presented organic additives. Synthetic zeolite - type Pc of cubic structure, loamy shale and dolomite limestone presented inorganic additives. Five soil types were used during the testing (arenic regosol, typic cambisol, dystric cambisol, typic chernozem and typic fluvisol). The changeover of the mobility of As, Cd, Pb a Zn in the soil (the ratio of mobile and total contents, sequential analysis) and the transfer of the elements from the soil into the plants (the vegetables, cereals and fodder plants) were investigated. The results showed the primary importance of the soil pH value on the behaviour of potentially toxic elements and their intake by the plants. The efficiency of the use of organic additives strongly depended on the quality of the organic matter. Inorganic additives on the base of the sorbents worked in the case of mobile hazardous elements (Cd, Zn). The efficiency of the soil additives was strongly influenced by the soil type.