The article dedicates to the results of the study of impact of Humilid on the content of heavy metals in biohumus and biomass of red Californian worm in the process of vermicultivation for 6 months.

The studies were conducted under conditions of vermifarm of "Natural Biotechnology" (Zaporizhzhya), which is a producer of vermicompost, liquid humic drug and biomass of vermiculture. The object of research was hybrid of red Californian worm and biohumus. The nutrient substrate was a mixture of fermented manure of cattle and fermented sunflower husk (wastes of mushroom production) in the ratio of 9:1. Clamps formed 5x0.5x0.15 m size and they were sown with vermiculture in the amount of 5–7 thousand average per 1 м². Fresh substrate was distributed by layer 7–10 cm across the surface of the clamp. Once every 7–10 days it was watered. The room temperature maintained in the range of 21–24 ⁰С, substrate humidity was in the range of 65–90 %, which corresponds to the normal conditions of cultivation. Research clamps differed from control clamps by the presence of biologically active additives "Humilid" [TU 15.7-00493675-004:2009] in an amount of 15 mg/kg of nutrient substrate, which was contributed once per month. Vermicultivation performed within 6 months.

On the 90 th and 180 th day of research in the substratum and in biohumus the samples of biohumus together with vermiculture were collected from control and tested clamps to prepare middle samples. The content of worms’ intestine was cleaned on the wet paper during two days. The moisture in the samples was defined by gravimetric method drying in the drying cabinet at temperatures of 105±2 ⁰C. Absolutely dry bіohumus and biomass of worms were chopped in the porcelain pounder and sieved in the sieve with a diameter of 1mm. In the prepared samples the content of heavy metals were defined by atomic absorption method.

Statistical calculations performed using the editor "Microsoft Excel".

To determine the impact of Humilidon the content of heavy metals in products of vermitechnology in the process of vermicultivation during the 180 days it was determined the amount of Lead, cadmium, copper and vermicompost in biomass of red Californian worm hybrid.

During the process of vermicultivation observed accumulation of heavy metals in vermicompost as in control and in the experiment. But at the same time, the use of Humilid contributed to a significant reduction of heavy metals in the tissues and the hybrid of red Californian worm.

It was established that at the end of the study Lead content in the tissues red Californian worm hybrid of control variant increased by 0.8 %, while in research observed a decrease of 24.3 % compared to its content at the beginning of the experiment. Compared with control, in the research worm biomass the content of Lead decreased by 24.8 % (p<0.01).

At the end of the study it was recorded the accumulation of cadmium content in biomass of vermiculture of control variant 4.5 % and its decrease by 27.7 % in research regarding its amount at the beginning of the study. Adding of Humilid to nutrient substrate caused reduction of cadmium in biomass of vermiculture 26.1 % (p<0.01).

At the end of the study the content of copper in vermiculture biomass accumulated in the control variant 5.9 %, at the same time, research variant observed a decrease 26.3 % compared to its content at the beginning of the study. However, the content of copper in the experimental version was less on 30.5 % (p<0.001) relatively to control.

Reducing contaminants in the tissues of vermiculture of research variant was possibly due to formation of chelate compounds of humic substances of Humilid with heavy metals. These complexes are not involved in the food chain and removed from the body of the worm with coprolites, which provides quality protein products of vermitechnology.

It was established that during vermicultivation for 6 months in vermicompost of control and experimental variants accumulation of heavy metals took place. Adding of Humilid to nutrient substrate does not significantly affect this process. However, in all cases the content of heavy metals in the vermicompost was well below the MCL of organic fertilizers.

It was established that the use of dietary supplements "Humilid" of 15 mg/kg of dry substrate during vermicultivation helped to reduce heavy metals in biomass of vermiculture. Thus, at the end of the study in biomass of worms the content of Lead decreased by 24.8 % (p<0.01), cadmium – by 26.1 % (p<0.01), and copper – by 30.5 % (p<0.001) relatively to control.

The effect of dietary supplement of humic nature "Humilid" to reduce heavy metals in biomass of vermiculture may be due to the fact that humic substances are able to irreversibly bind heavy metals. The result is inactive insoluble complexes which are derived from the cycle of matter. This improves the livelihoods of individuals of vermiculture.

Use of Humilid in vermicultivation is important because the additive helps to ensure biosafe products as organic fertilizers – vermicompost and vermiculture biomass that can be used as feed additives for farm animals.

Key words: biohumus, vermiculture biomass, Humilid, heavy metals, Plumbum (Lead), Cadmium, Copper.