Evaluation of fertility of reclaimed agricultural soils after construction of inter-settlement gas pipeline

Abstract

Reclamation of agricultural soils after the construction of a gas pipeline is an obligatory process that requires complete restoration of the fertile layer. The studies have determined that the reference and technogenic agricultural soils have significant differences in potential and effective fertility which is due to the consequences of reclamation. It has been determined that in terms of humus horizon thickness, the reference agricultural soils are medium-thick, and in terms of humus content, they are slightly humic. In technogenic agricultural soils, the humus horizon is conditionally preserved, degraded by 56-70% and represented by mixed parent rock and eluvial-illuvial horizons. Humus content in the technogenic soil is poorly diagnosed, inclusions of spots are observed, and the differences with the standard make 62-66% which sometimes corresponds to the parent rock. By comparing the effective fertility of the reference and reclaimed agricultural soils, it was found that major nutrient elements have undergone the greatest changes. For example, in the reference agricultural soil, the content of nitrogen and phosphorus is at the average and high levels of availability, potassium - at the average and high levels. In technogenic agricultural soil, their content is at a very low level. With aggressive degradation of this level, meso- and microelements are less dynamic, as is the reaction of the environment, since their content in the humus horizon is largely determined by the parent rock. To restore technogenic soils to the level of the standard, a calculation method has been developed that makes it possible to compensate for a possible lack of fertility elements. This possibility may also be achieved at the expense of the donor soil.