CHANGES IN THE QUALITY STATUS OF ARABLE GRAY SOILS OF THE NORTHERN AREA OF THE REPUBLIC OF MOLDOVA USED IN AGRICULTURE PUBLISHEDTamara Leah, Valerian Cerbari, Nicolai Leah None firstname.lastname@example.org
The arable Grey soils of the Northern area of the Republic of Moldova, compared to the natural (virgin) ones, are characterized by a moderate degradation of the properties as a result of the dehumification, destructured and considerable decrease of biophilic elements content. The texture of the arable and virgin gray soils is practically analogous - clayey in the upper part of the profile and clayey-loamy in the illuvial or iluvial-cambic horizons. In the recent conditions of the structural state of the arable layer of these soils, the clay texture can be appreciated as good in terms of soil tillage. Due to the clayey texture the arable layer works comparatively easily, the plow is less bulky than in the case of the fine textured soils (clayey-loamy, clayey or loamy-clayey). The texture of the illuvial (illuvial - cambic) horizons Bhtw and Btw is clayey-loamy. The medium-fine texture and the monolithic structure have led to the excessive compaction of these horizons and formation an unfavorable physical quality state. The arable gray soils are relatively poor in humus and nutrients; the presence of compact illuvial horizons leads to decreasing the water permeability and, as a result, they are periodically influenced by the temporary excess of humidity; they have a comparatively weakly anti-erosion stability (soils with medium texture, medium-coarse and coarse); their natural fertility is relatively low. The acidity of the arable soils decreased considerably, which led to stopping the eluviation-illuviation process, but it remained enough high. The illuvial horizons of virgin and arable gray soils are characterized by unfavorable chemical and physical properties - excessive compaction, acid reaction, low nutrient content. The continued use of arable gray soils under conditions of organic and chemical fertilizer deficiency will lead to further depletion of nutrients and organic matter, to aggravation of their quality status. The main pedoameliorative measures for these soils are: increase the organic matter content in the arable layer using mineral and organic fertilizers, green fertilizers, organic and waste residues, implementation of zonal crop rotation; improvement of the soil tillage system - once in 3-4 years the plowing at a depth of 35 cm to crush the newly strongly compacted postarable layer, the periodic tillage with the chisel at a depth of 40-50 cm for partial loosening of the extremely compact natural illuvial horizon.
gray soil, compactation, organic matter, structure, northern area of R.Moldova