FIELD: agriculture.
SUBSTANCE: invention refers to biological purification of soil polluted with heavy metals. The method consists in growing plants on deactivated area; through their root system plants accumulate radio-nuclides and heavy metals contained in soil; further the method consists in removing growth and in its successive utilisation. As remedy for soil deactivation from heavy metals there are used plants of Glycyrrhiza giabra L. Glycyrrhiza uralensis Fisch. and amaranthus purple; four-five years old cuttings from roots of Glycyrrhiza are planted on deactivated area and plantations of Glycyrrhiza are grown; also cuttings are of 0.20-0.25 m length, diametre of 8-20 mm with four-six accessory buds and they are planted at depth of 0.16-0.22 m with row-spacing of 2.1-2.8 m in two mutually perpendicular directions with seeding rate 21500-28600 pieces per hectare. In first two years of plant vegetation there is performed drop watering along rows of plants at rate of dropper consumption from 2 to 4 l/h with interval of their placement 0.3-0.4 m in a cavity of flexible watering pipelines. During September-October by the end of vegetation of the third year growth of Glycyrrhiza and associated grass on the deactivated area vegetation mass is low-cut mowed and piled into silo pits. Each year at beginning of the fourth, fifth and sixth year of plant growths there is carried out sowing of seeds of amaranthus; sowing is direct without cultivation of soil with row spacing 0.7-1.4 m at depth 0.5-1.5 cm and at seeding rate of 8x106-12x106 pieces/hectare. Vegetation mass of Glycyrrhiza and amaranthus is mowed and chopped in August of each year, and chopped mass in form of cutting is piled into the same silo pit. Brine of natural mineral bischofite of 1.1-1.3 t/m at rate of 200-400 l per ton of raw silo mass is introduced between layers of silo mass of thickness 0.3-0.6 m. Starting from the eighth year of plants growing in the plantation there is performed extraction of Glycyrrhiza root at depth of 0.4…0.6 m with exposing roots and rhizomes of Glycyrrhiza to day surface leaving stripes of virgin zone of 0.6-0.8 m width as zone of reservation. Root mass of Glycyrrhiza is subject to extraction with successive production of thick and dry Glycyrrhiza extract for industrial application. Freak parts of the roots and rhizomes of Glycyrrhiza and wastes of extract production are mixed with silo above-soil mass of Glycyrrhiza and amaranthus in pits. Late in autumn produced organic fertiliser saturated with microelements from bischofite brine is strewn on surface of cultivated stripes at extraction of root mass. The upper layer of soil in each stripe is milled with a rotary tiller at depth of 0.10-0.16 m till obtaining agronomic valuable soil aggregate; further the upper layer is compacted with a water-filled roller at pressure of 0.16…0.32 MPa. In a year repeated extraction of root mass of Glycyrrhiza is performed in another direction of cutting planting. There is facilitated phyto-deactivation of root inhabited layer of soil, ground and upstream water.
EFFECT: facilitating phyto-deactivation of root-inhabited layer of soil, ground and upstream water.
24 dwg, 21 tbl
