Differences in the phenologic development of forage grasses on mineral and organic soil

The soil type impact on the heading stage commencement and its duration was evaluated on thirty-four varieties of the six following grass species: nine varieties of Dactylis glomerata (L.), four of Festuca pratensis (Huds.), four of Festuca rubra (L.), six of Lolium perenne (L.), seven of Phleum pretense (L.) and four of Poa pratensis (L.). The investigations were conducted in a natural meadow habitat on the organic and mineral soil under the same weather conditions. Over the vegetative period a ground water level ranged from 173 to 232 cm on the mineral soil and 23-86 cm on the organic one. The evaluated varieties entered the heading stage on the organic soil later as compared to mineral. The differences in this stage commencement was greatest between the Lolium perenne varieties on mineral soil and between Dactylis glomerata varieties on organic, whereas the smallest between Dactylis glomerata and Poa pratensis varieties on mineral soil. Among the varieties of the species examined there were distinguished some less soil factor-sensitive ones and those showing a long period from the heading start to flowering commencement.