Clearing and Soil Improvement Work

the set of measures used to improve natural feed lands and develop new lands (drained marshes, overly moist lands) for use in agriculture. Clearing and soil improvement work is divided into two groups: (1) activities to prepare land being developed for further working, such as removing trees and stumps, clearing away brush, removing wood and boulders from the plow layer, breaking up tussocks, removing rocks, and grading; and (2) activities to make the soil suitable for cultivation and improve its physico-chemical and biochemical properties during the process of the initial development and initial working of the soil (planting preliminary crops, applying fertilizers, regrassing).

Clearing away wood and brush involves cutting down bushes and trees, digging out large roots from the soil, and raking up and removing all masses of wood from the plot. In the chemical method of clearing, arboricides are applied to vegetation. Chemical clearing is done primarily in plots overgrown with alder, birch, aspen, and willow; no more than 25 percent of the tree species can be resistant to the chemicals. Treatment is given in the spring before large-scale appearance of leaves, during the summer from the second ten days of June through the month of July, and in the autumn immediately after leaves fall. Bushes and trees that have been treated are removed from the plot after the wood decays sufficiently and loses its mechanical strength. Thickets up to 5 m high are removed the following year after repeated treatment; larger trees and brush are removed after 2–3 years. Removal of stumps and large trees, one of the laborious clearing and soil improvment jobs, is done by stump-pulling machines. The stumps are collected in heaps and burned or removed from the plot. The holes that form as a result of stump-pulling are filled in with earth and leveled. Stones are removed during surface improvement of meadows; with deep improvement they are also extracted from the soil horizon.

The initial working of newly developed lands includes a set of operations whose technology depends on natural conditions. Soil tillage is used to break up sod and create a plow layer with favorable characteristics for agricultural plants. Meadows with sod not more than 10–15 cm thick are plowed with plows equipped with skim colters; meadows with thicker sod are plowed with brush-marsh and virgin-land plows. On solonets soils a subsoil plow is used at the same time. When developing forest land and on peats with buried wood, tilling is done with disk or uprooting harrows without a moldboard. Rototilling is done on land that has tussocks and heavy sod. On lands with thick sod and on drained marshes regrassing is done after raising field crops for 1–3 years. A mixture of meadow grasses is used for regrassing.