Botanicna sestava in pridelek zelinja mesanic trav z belo deteljo v odvisnosti od gnojenja z dusikom pri kosni rabi.
1993
Cop J. | Korosec J.
Botanical composition and herbage yield are influenced by sown grass/clover mixtures and N fertilization. Over 3 yrs (1990-92) a field trial using a split-plot design in 4 replications was carried out at Ljubljana (46 deg. N, 14 deg. E, alt. 298 m). The objective was to find out how mixtures (I) timothy, perennial ryegrass, meadow fescue, meadow grass, red clover, white clover, (Il) cocksfoot, white clover, (Ill) perennial ryegrass, white clover and level of N fertilization (0, 200, 400 kg N/ha/yr) influence the composition and herbage yield of mixtures at 6 cuts. The grasses were sown at a 70% rate from that in monocultures and clovers at a 30 % rate. The content of clovers in mixtures with zero N increased with the trial duration from 35% in the seeding yr to 59 and 67% in the harvest yrs. The clover content in mixtures with 200 kg N was 5-8%, and 17% in the 3rd yr. In mixtures with 400 kg N the clover content was as low as 1 - 3%. In the 3rd yr the content of herbs increased within the complex mixture with 400 kg N. Due to N fertilizing, the herbage yield increased relatively the most in the sowing yr. Following yrs the mixtures with zero N yielded not much less than that of the fertilized ones, which was due to biological fixation of N2 (average difference: 0.78 t DM/ha/yr when 200 kg N applied and 2.39 t when 400 kg N applied). When compared with 2 other mixtures, cocksfoot in the mixture with white clover grew slower in the unestablished sward and showed stronger response to the N fertilization.
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