The long-term field experiments of the Selectia Research Institute of Field Crop, located in the North part of Republic of Moldova, provide precious data regarding the soil state under different agroecosystem management practices: crop rotations, fertilization systems, permanent crops – which also include extreme agroecosystems: fallow and black fallow. The paper referres to the study of chernozem physical state, characterized by soil structure – an „architectural” view of the soil profile. The soil samples were collected from the 0-40 cm soil layer at each 10 cm. The researches has shown that there are some key agricultural practices: less mechanic disturbance of the soil; the use of legumes and perennial grasses mixture; crops diversification; the organic fertilizer use – that beneficially influence the restoration and maintaining of soil structure in agroecosystems. The best soil aggregation attests in the fallow, a reproduced variant of the natural steppe ecosystem, and the extreme opposite - the black fallow, due to the „aggressive” management, has unstructured soil.