Biomass formation and yielding of selected cultivars of the low grasses in pure stand and in the mixtures

The aim of the study was estimation of some morphological and biological features and yielding of seven grass cultivars sown for fodder production on grassland. The objects of the study were cultivars of three low-growing grass species: Lolium perenne, Poa pratensis i Festuca rubra. The cultivars were evaluated in the next four years of utilization. Tillers density, growth rate of sward, earliness, yielding and yield structure of the first regrowth in pure stands and in two mixtures were evaluated. In the sowing year and in the third year of full utilization the underground biomass in the topsoil was also determined. The L. perenne cultivars were ranked, in terms of their earliness, in the following order: Naki (early), Diament and Gagat (mid-early), Bajka (late). It was found that L. perenne cv. Bajka was characterised by a greater tolerance to changing weather conditions (drought and frost) compared to other cultivars of that species. Among P. pratensis cvs., Eska-46 revealed more favorable features

Evaluation of biological characteristics and yield of selected varieties of Dactylis glomerata, Festuca pratensis and Phleum pratense in pure stands and mixtures

The aim of this study was to estimate yielding of varieties of some tall grass species in pure stands and two meadow mixtures differentiated in earliness. Three cuts were made. The first one was made in full of heading phase, in pure stands – of individual varieties and in mixtures – of varieties dominated in sward. Cover, growth rate of sward height, contribution of generative shoots, their number and mass in the first cut, annual DM yield and R/S ratio (root/shoot) was evaluated. In pure stands the yield varied most among varieties of F. pratensis and Phl. pratense but least – with D. glomerata. The results show that yield of the early mixture was better irrespective of re-growth. In early mixture dominated D. glomerata var. Amera while F. pratensis var. Pasja in mid-early mixture

Effects of mowing cessation on Molinietum caerulae meadow vegetation

Badania przeprowadzono w 2010 r. w Środkowym Basenie Biebrzy w Biebrzańskim Parku Narodowym. W celu określenia wpływu zaprzestania koszenia na roślinność, na obiekcie łąkowym Grzędy wytyczono dwa transekty - jeden w części niekoszonej od 7 lat, drugi - w części sporadycznie koszonej (raz na 2-4 lata). W ramach transektów wykonano łącznie 23 zdjęcia fitosocjologiczne metodą Brauna-Blanqueta. Obliczono wskaźniki Elleneberga: F - uwilgotnienia, N - zawartości azotu w glebie i R - odczynu gleby. Oceniono różnorodność gatunkową zbiorowisk na podstawie: łącznej liczby gatunków w transekcie, średniej liczby gatunków przypadającej na zdjęcie fitosocjologiczne oraz obliczając wskaźnik różnorodności gatunkowej Shannona-Wienera dla transektów. Wartość użytkową zbiorowisk oceniono na podstawie LWU Filipka i zadarnienia. Stwierdzono, że skład gatunkowy zbiorowisk w obu transektach jest podobny, jednak wyraźnie różni się proporcjami. Na całym obiekcie dominują fitocenozy zespołu Molinietum caerulae W. Koch 1926 (klasa Molinio-Arrhenatheretea R. Tx. 1937). W części, na której przed 7 laty zaprzestano koszenia, w płatach zaznacza się wyraźny podrost drzew: Salix cinerea L., Salix repens subsp. rosmarinifolia (L.) Hartm. i Betula pubescens Ehrh., co świadczy o postępującej sukcesji wtórnej. W porównaniu z obszarem sporadycznie koszonym większa jest średnia wysokość roślin, natomiast mniejsze - zadarnienie. Na obszarze koszonym udział gatunków drzewiastych jest znikomy. Z większą ilościowością występuje tu Carex panicea L. i Carex buxbaumii Wahlenb. Zaprzestanie użytkowania spowodowało wzrost łącznej liczby gatunków w transekcie i średniej liczby gatunków w zdjęciu, ale zmniejszenie wartości wskaźnika Shannona-Wienera. Wartość użytkową roślinności obu badanych transektów oceniono jako bardzo słabą.The study was carried out in the year 2010 in the Middle Basin of the Biebrza River in the Biebrza National Park. The aim was to find out if the cessation of mowing could have changed some parameters of the existing vegetation. And if yes - what kind of changes could be noted. The examined phytocoenoses were described by 23 relevčs made with the BRAUN-BLANQUET method (1964). Eleven of them were made within the transect where vegetation had been mowed every 2-4 years, and the other 12 - in the transect, where vegetation had not been mowed for the previous 7 years. Species diversity was assessed upon: species composition of each community, their syntaxonomic structure, species richness, floristic diversity calculated using the SHANNON-WIENER index (H') and site conditions estimated with the ELLENBERG phytoindication method (1992]. The utilization value based on the fodder value score (FVS) defined by FILIPEK (1973) and sod cover were also estimated. It was found that species composition in both transects was very similar, however, the proportion of some species and syntaxonomic groups of species was different. Generally, the whole examined area was covered by the phytocoenoses of Molinetum caerulae association. In the not mowed part the clear symptoms of secondary succession were noticed. Young trees and shrubs, mainly Salix cinerea, Salix repens subspec. rosmarinifolia and Betula pubescens, appeared in vegetation units. In comparison to the mowed area the total number of species in the phytosociological relevé and mean height of plants were higher, whereas the sod cover was lower. In the mowed area the mean cover of trees and shrubs was negligible. Carex panicea and Carex buxbaumii were numerous there. Other results of the abandonment of utilization were: a higher species richness and a lower value of Shannon-Wiener index. The utilisation value of vegetation in both examined transects was very poor