Considerations on physical and chemical properties of typical chernozem from Topraisar area, Constanta County and proposals to improve its use.

This paper studies typical chernozem, specifically for the Topraisar and Amzacea area, Constanta County. This soil type is characteristic for Central Dobrogea, as well as for other lowland regions of Romania. Its intense exploitation in agriculture caused changes in some certain properties. In this paper, the main properties of typical chernozem are studied. For physical, chemical and microbiological soil characterization samples from the soil profile were collected. Tthe following parameters have een determined: soil texture, soil structure in plowing and underlying horizons, the degree of compaction, soil porosity, total cationic exchange capacity, nutrients storage, pH, calcium carbonate content, organic matter content and soil microbial activity. The land evaluation marks have been also calculated for this soil type and changes in yields values due to the changes of the restrictive indicators coefficients have been highlighted. The high natural fertility of this soil, the high content of organic matter and nutrients recommended it to be used for a variety of crops cultivated in these areas. Intense exploitation in agriculture, the use of farm machinery with high weight and the execution nu e application? of soil tillage at inappropriate soil moisture, determined certain soil properties changes. The aim of this work paper was to highlighting these soil characteristics which have been modified under the influence of anthropogenic factors. The research found that, between them, the reducing of soil porosity and the increasing of soil compaction in horizons under plowed layer of soil are the main features that led to a decreasing agricultural production. Interpreting the data collected from field, laboratory test results and determining the land evaluation marks for the study area, it was concluded that the indicator which is responsible for the decrease of agricultural production is the climate conditions and the low soil porosity. This soil characteristic was induced by human activities. To eliminate the negative impacts of it, specific measures of land use have been proposed.