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Problems concerning total dry weight and distribution of underground phytomass were studied in a pasture trial at Rapotin near Šumperk, the Czech Republic in the period 1995-1999. The total weight of dry underground pasture phytomass (DUP) was 976 g/m 2 (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/m 2 , i.e. 92 g/m 2 (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/m 2 DUP were determined, i.e. by 60 g/m 2 (5.5%) less. The highest DUP weight in the period 1996-1999 was found in autumn 1997 (1222 g/m 2 ) 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/m 2 ) and fertilized (952 g/m 2 ) plots, respectively in a layer of 0-100 mm.

The effect of fertilization and the harvest frequency on production and floristic characteristics of a meadow stand were assessed in a small plot trial established in 2003 in Vatín, Vysočina Region, the Czech Republic. Four levels of fertilization (none; N0 + P30 + K60 kg∙ha−1; N90 + P30 + K60 kg∙ha−1; N180 + P30 + K60 kg∙ha−1) were combined with four treatments of exploitation intensity (4 cuts per year, first cut on 15th May, every next after 45 days; 3 cuts per year, first cut on 30th May, every next after 60 days; 2 cuts per year, first cut on 15th June, next after 90 days; 2 cuts per year, first cut on 30th June, next after 90 days). Production of dry matter and proportions of guilds (grasses, legumes, and other species) were evaluated. Data from 2009–2011 were used in this paper. Yields of the dry matter increased along with increasing amounts of nutrients supplied and ranged from 3.8 t∙ha−1 (non-fertilized) to 9.1 t∙ha−1 (N180PK). The nutrition level had a significant effect on spread of grasses, which reached maximal proportion of 52.3 % under N180PK fertilization compared to 42.1% on non-fertilized plots. On the contrary, legumes flourished well in treatments without N-supply, attaining proportion of 6.8 % and 5.1 % on PK-fertilized and non-fertilized plot, respectively. With regard to the exploitation intensity grasses profited from extensive management by contrast to the group of other species which reached its maximum in swards harvested four times a year. Proportions of legumes did not show significant dependence on the cutting frequency.

In 2004-2009, a small-plot trial was conducted on permanent grassland dominated by Festuca arundinacea Schreb. on the mesohygrophytic site in order to evaluate effects of four levels of nutrition: F 1 = without NPK fertilization, F 2 = P 30 + K 60 , F 3 = N 90 + P 30 + K 60 , F 4 = N 180 + P 30 + K 60 kg/ha), four levels of cutting intensity (I 1 -4, I 2 -3, I 3 -2, early, I 4 -2, late cut) and their interactive influence, i.e. a total of 16 variants on the production of forage dry matter, production of crude protein (CD) and net energy of lactation (NEL) per hectare. The dominant influence of N-nutrition is documented by significant differences in forage dry matter (DM) production between the variants (with the exception of F 1 /F 2 ) ranging from 4.41-4.80 to 8.44-9.83 t/ha. The effect of different exploitation level on the production is subdominant and no significant differences were found either in the production of forage DM (I 1 -6.41 -I 2 -6.59 -I 3 -6.97 -I 4 -7.50 t/ha) or in the production of nutrients. Management models to be recommendeed for the given type of sward with respect to the interactive influence, efficacy of forage production and quality are as follows: (a) three cuts/180 kg N + PK/ha with forage suitable for dairy cows; (b) two cuts/90 kg N + PK/ha with forage suitable for cattle breeds kept for meat.

In addition to the results published in the first communication (Opitz von Boberfeld et al., 2006) this paper presents crude protein, energy (ME) and ergosterol concentrations of autumn saved herbage at different sites in Central Germany, Poland, Hungary and the Czech Republic. Within these sites, the influence of the factors pre-utilisation and winter harvest date was tested over three consecutive years. Related to the different climatic conditions of the sites, crude protein concentrations of the growths pre-utilised in July varied from 149 g/kg in November to 134 g/kg of dry matter (DM) in January. The influence of climatic conditions was different on each location and varied depending on the year. Generally, the consistent effect of the factor "site" related to altitude could not be observed. While the energy concentrations decreased with advancing winter and partly reached the values below 6 MJ ME/kg of DM in January, the ergosterol concentrations increased. The results demonstrate that under Central European conditions autumn saved herbage, pre-utilised in July, could provide adequate quantity and quality for suckler cows until December. Afterwards, the utilisation of preserved forages becomes essential.

Based on three-year results of a field experiment evaluating aboveground biomass production and the number of stems of above-ground shoots of grass species (Lolium perenne, Dactylis glomerata, Festuca pratensis) grown in a 200×200 mm layout in two water regime variants (normal and reduced -50% of precipitation) and further in two variants of mowing intensity (meadow -3 mowings, grazing -5 mowings per year), the following has been ascertained. The most productive species on averages of the two moisture regimes is Dactylis glomerata, Lolium perenne and Festuca pratensis have fodder weight significantly lower by 20.8% and 22.6% (meadow var.) and 16.9% and 21.9% (grazing var.). Reduction of moisture significantly decreased the above ground biomass weight in case of meadow exploitation in Dactylis glomerata −41.2%, in Lolium perenne by −9.9% and in Festuca pratensis −33.5%. In case of grazing exploitation, the influence of "drought" on production was less pronounced. Dactylis glomerata provided the same output, in Lolium perenne there was a decrease of −15.7% and in Festuca pratensis −11.9%. Reduction of precipitation significantly decreased shoot formation particularly in case of meadow utilization in Lolium perenne −23.7%, Dactylis glomerata −34.7% and Festuca pratensis −20.5%. In case of grazing utilization, reduction in the number of pseudostems due to "drought" was lowerin the order of the above species -27.1% -4.6% -9.6%. Generally, compared with meadow utilization, grazing utilization decreases fodder production in both moisture regimes and increases the number of above-ground shoots.

MÜLLER, M., HRABĚ, F.: Eff ect of owersowing on yields and botanical composition of pasture sward. Acta univ. agric. et silvic. Mendel. Brun., 2008, LVI, No. 4, pp. 127-134 There are several metods of permanent pasture renovation. Diff erent technologies were investigated on a pasture sward. Three seeders (Einböck seeder with the tine harrow, no-till Sulky disc seeder and SPP 8 strip seeder) and two fertilization regimes (with no fertilization and with mineral fertilization N 90 P 30 K 60 kg.ha ) were used to determine optimum methods of establishment and the use of oversowed pasture swards. In the fi rst year, renovated plots had a higher DM production than control plots. The pasture oversowing had no eff ect on herbage production in the second production year. The fertilization had no eff ect in the fi rst production year with a higher clover content in the sward. The share of clovers was higher in plots oversown with the Einböck and Sulky seeders but only in the second and third cuts of the fi rst production year and in the third cut of the second production year. The highest content of clovers was observed in the second and third cuts. There was a positive correlation between the clover content in DM yield and herbage DM production. The oversowing did not show any eff ect on the grass content in the pasture sward.owersowing, pasture, clover, fertilization Jednou z metod, jak zlepšit travní porost s nevhodným druhovým složením, který nevyhovuje požadavkům na zajištění produkce dostatečného množství kvalitní píce, je provedení jeho obnovy formou bezorebného přísevu. Bezorebným příse-vem lze docílit uchycení nových výnosnějších a kvalitnějších druhů ve stávajícím travním porostu (Muto a Martin, 2000; Pavlů et al., 2000). Největší význam se v současné době přisuzuje přísevu jetelovin díky jejich vysoké produkci, vysoké kvalitě píce, rovnoměr-nému rozložení výnosu v průběhu roku a schopnosti symbiotické fi xace dusíku, která umožňuje úplnou a nebo částečnou náhradu hnojení dusíkem (Bukvaj, 1991;Guretzky et al., 2004;Hrazdíra, 1989;Laberge et al., 2005;Mourino et al., 2003;Sleugh et al., 2000). Dalším efektem je, že zvířata pasoucí se na porostech jetelovin vykazují vyšší přírůstky a vyšší produkci z jednotky plochy než při pastvě na čistě travních porostech (Mourino et al., 2003). Přiseté travní druhy usnadňují konzervaci silážováním díky vyššímu obsahu cukrů a rovněž zlepšují hustotu porostu, která je spojena s menším znečištěním píce při sklizni (Buchgraber, 1996). Podíl bylin by neměl překročit určitou mez, jinak dochází ke snižování kvality zejména při sklizni ke konzervaci (Buchgraber a Gindl, 2004).Pro přísev byly vyvinuty stroje pracující na růz-ných principech zapravení semen do půdy, mechanického narušení povrchu a omezení konkurenční schopnosti původního porostu (Buchgraber a Pötsch, 1994a Tišliar, 1993. Konkurence mezi pů-vodním porostem a novými rostlinami silně ovlivňuje úspěšnost přísevu. Jedná se jak o konkurenci o vodu, vzduch a živiny, tak i o vylučování různých alelopatických látek in...

The objective of the paper is to assess the species composition of grass stands used under regime of two and three cuts, the grassland species diversity and the grassland quality at different levels of nutrition. The experimental site is situated in the Bohemian-Moravian Upland at an altitude of 650 m a.s.l. The subjects of assessment are two-cut and three-cut grass stands with diverse intensities of nutrition: unfertilized, 30 kg ha−1 P and 60 kg ha−1 K fertilized, fertilized with 90 kg ha−1 N+PK, and fertilized with 180 kg ha−1 N+PK. Studied characteristics were as follows: share of dominant species in the harvested herbage, species diversity of the grass stand and grass stand quality. Evaluated were years 2002–2006. The two-cut use promoted development of Dactylis glomerata. The three-cut use promoted development of Poa ssp. The share of Alopecurus pratensis was equable in the two-cut and three-cut grass stands. The dose of N90+PK promoted Dactylis glomerata and was insufficient to increase the share of Alopecurus pratensis and Poa ssp. Fertilization resulted in the decreased share of most present herbs but de­ve­lop­ment of Polygonum bistorta was promoted, namely by the dose of N90+PK. In contrast, the application of PK promoted Trifolium repens. Fertilization had a significant (P < 0.05) influence on the share of individual species in the grassland. Three-cut grass stands exhibited a higher diversity than two-cut grass stands did. Fertilization had a significant (P < 0.05) influence on the decreased species diversity and on the increased grassland quality.