1 Research Institute of Mountain Stockbreeding and Agriculture, 5600–Troyan,
281 Vasil Levski Street, Troyan, BULGARIA
Corresponding author: E–mail: firstname.lastname@example.org
Abstract. In the period of 2014–2016 at the Research Institute of Mountain Stockbreeding and Agriculture–Troyan, Lumbrical and Lumbrex bioproducts were tested in a field experiment on a grassland of bird’s–foot–trefoil with ‘Leo’ cultivar. Organic fertilizers are high in humic and fulvo acids, macro and micro elements. They are a result of the processing of organic waste through the red earthworm (Lumbricus rubellis) and the application of modern biotechnology. The results show that the independent introduction of the studied preparations has a positive influence on the density of Lotus corniculatus L. in the grassland. The main crop in the harvested biomass prevails in the soil and leaf feeding variants with 3.9 and 1.2–2.7 percentage units, respectively. The weed vegetation is reduced more significantly mainly in Lumbrical variants, regardless of the fertilization level. The liquid fraction of Lumbrex, introduced in the bud–formation period – beginning of blossoming at a dose of 150 and 200 mL/da, had a slighter influence on the participation of bird’s–foot–trefoil (89.8–91.4 %) in the total biomass as well as the level of weed infestation, while it increased more significantly the amount of leaf mass. The percentage share of variants with foliar treatment exceeded the control with 7.0 (Lumbrex 150 mL/da) to 10.4 (Lumbrex 200 mL/da), and those with soil nutrition with 1.5 (Lumbrical 150 mL/m2) and 4.3 (Lumbrical 200 mL/m2) percentage units.
Keyword: Lotus corniculatus L., Lumbrical, Lumbrex, bio–fertilization.