GROWING RUSSIAN BROOM FOR SANDY SOILS PHYTOMELIORATION

Abstract

Russian broom (Cutisus ruthenicus) is one of the soil-improving and nitrogen-fixing plants. However, there is lack of study of agricultural methods of growing Russian broom for sandy soil phytomelioration. The goal of the research is to assess the Russian broom reproductive activity, to study the influence of the methods of seeds preparation and seeding time on                             morphometric figures of the containerized seedlings and their growth in plantations. Objects and methods of research. The biometric data and seed production of Russian broom was studied in  dry and wet coniferous forests of Kokshayskoe forestry, the seedlings were grown in the greenhouse of Botanical Garden Institute, Volga State University of Technology (Republic of Mari El). To grow the containerized seedlings, Ardatov-40 containers (76 сm³ cell volume) were used. Results.  In wet coniferous forest, the height of Russian broom shrubs on the open area varies from 0.5 to 1.8 m. The mass of overground part is 1300 g, root system is up to 2.7 m in depth.  Russian broom leaves contain 1.4% nitrogen, 0.113 % phosphorus, and 0.127 % potassium. The humus content in the soil under Russian broom crowns is 4.75 %, total nitrogen  - 0.34 %. In plots with no Russian broom, there is half as much humus (1.86 %), the content of nitrogen - 0.11%. High intensity of physiologic processes of Scots pine in the plantations with Russian broom was determined, photosynthetic rate of pine in June was 4.2±0.36 mg СО² / g per hour, the content of total chlorophyll - 2.4±0.16 mg/g of dry weight. In pure plantations, these figures are 3.1±0.23 mg СО² / g per hour and 2.1±0.13 mg/g of dry weight, correspondingly. Mean seeds  production of Russian broom is 155 g of one shrub, seed efficiency is 25.6 g. The seeds were scarified to overcome the seed coat impenetrability and get quick soaking of seeds. One-year seedlings of the scarified seeds are 24-28 сm in height, but in the check seeds their height is no more 20 сm. The positive impact of autumn seeds sowing in the containers on the height figures and the top of one-year seedlings was defined. The development of nodules of nitrogen-gathering bacteria on the roots was  recorded. One-year plants grown of the seeds sowed in the containers in autumn show   21.0±1.0 сm mean height, the plants sowed in spring – 13.4±0.8 сm. The differences are vital at the confidence level 0.95, t _table.= 2.1 at a t _fact.=5.6. Survival ability of the containerized seedlings of Russian broom when establishing in the planting area is 100 %. Conclusion. When growing Russian groom, autumn seed sowing in the containers may be considered to be the most efficient method. Development of nodules of nitrogen-gathering bacteria on the roots of Russian broom in autumn sowings contributes to more intensive growth after its establishment in the planting area. Establishment of Scots pine plantations with Russian broom favours soil fertility, promotion the intensity to major physiologic process, stability improvement to the unfavourable factors, conservation of forest environment and biodiversity of artificial plantations.