Institute of Forage Crops, 89 “Gen. Vladimir Vazov” Str., Pleven 5800, Bulgaria,
Abstract. Effect of the treatment with organic fertilizer Humustim on root biomass accumulation in vetch (Vicia sativa L.) (cv. Obrazets 666) was studied in a field trial carried out at the Institute of Forage Crops, Pleven, Bulgaria. Several doses of fertilizer were applied to the seed as a pre–sowing treatment, and during the vegetation growth phase (growing up and flowering stage), and as a combination between them. It was found that Humustim applications at all stages and rates resulted in increased root biomass. Plants accumulated from 661 to 717 kg/ha fresh, and from 254 to 280 kg/ha dry root biomass, which was 17.3 and 19.7%, respectively more than the untreated control. Humustim represent an excellent fertilizer in the modern trends such as sustainable agriculture and organic farming.
Keyword: Humustim, organic fertilizer, root biomass, vetch