The effect of main mineral fertilizers application and plants nutrition area on the quality of thyme raw plant materials (Thymus vulgaris L.) under irrigation conditions

The impact of nutrition area on Thymus vulgaris L. accumulation of essential oils in dry raw materials (Thymiherba) was studied and described in the article. Four schemes of cultivation were chosen to be studied: 45×40 cm — 56 thousand plants/ha, 45×30 cm — 74 thousand plants/ha, 45×20 cm — 111 thousand plants/ ha, 45×10 cm — 222 thousand plants/ha. It was shown that the increase of nutrition area helped to increase the content of essential oils in dry raw materials. Dry thyme grass with the highest content of essential oil 21.3 ml/kg was obtained when variants with the largest plant nutrition area were applied (the schemes of cultivation 45×40 cm — 56 thousand plants/ha). Reduction of the nutrition area decreased the essential oil content. According to the scheme of cultivation 45×30 cm (74 thousand plants/ha) content decreased to 20.8 ml/kg, and for the minimal nutrition area 45×10 cm (222 thousand plants/ha) the content of essential oil was 18.5 ml/kg. It was confirmed that main part of the essential oil in the raw thyme is contained in leaves, flowers and small sprouts. At the same time the woody stems contain essential oil only in trace amounts. According to the cultivation scheme 45x10 cm (222 thousand plants/ha) the leaves contained 34.2 ml/kg of essential oil, when the stems only 2.1 ml/kg. When the area of plant nutrition was increased the quality of raw materials slightly improved — for the scheme of cultivation 45x30 cm (74 thousand plants/ha) leaves contained 35.9 ml/kg, stems — 2.1 ml/kg of essential oil. The content of essential oil in the leaves was the highest — 36.2 ml/kg while using the scheme with maximum researched plant nutrition area 45×40 cm (56 thousand plants / ha). The efficiency of four norms of basic mineral fertilizers application was investigated: N0P0K0, N60P60K60, N120P120K120 and N180P180K180. It was found that increasing the rate of fertilizer application increased the yield of dry raw thyme and the content of essential oil. The most effective rate of fertilizer application is N180P180K180, which provided a dry leaves yield of 2.48 t/ha with an essential oil content of 38.2 ml/ha.The results showed that with the increase of the number of plants per unit area, the share of leaves in the total mass of raw materials decreased from 52.3% to 45.1%, but due to a significant increase in plantation productivity, dry leaf yields increased. The highest productivity was recorded for the variant of cultivation schemes 45×10 cm with a planting density of 222 thousand plants/ha, where the yield of dried thyme leaves was 1.52 t/ha.