International Scientific Journals
of Scientific Technical Union of Mechanical Engineering "Industry 4.0"

Applying appropriate tillage systems, agro-technical and ameliorative measures can stop the negative changes in soil functions and stabilize and improve soil fertility through a systematic agro-technical approach.
The aim of the study is to investigate the effect of the introduction of new solutions in agro-technology on cultivation of arable crops on soils with impaired fertility. In a three-field crop rotation with potato, wheat and corn cultivation, after the application of soil tillage and liming systems, it has been found that soil tillage systems have a direct and indirect impact on the productivity of crops grown under crop rotation, setting the conditions for the cultivation of crops other agrotechnical activities.
The deeper basic cultivations applied to the potatoes on Chromic Luvisosl and EutricPlanosols, leads to lower values of bulk density and strength.
Potato cultivation has a significant effect on both limestone and ash input, with a positive effect on corn and wheat.
On the basis of the results obtained from the field experiments, a technology for the production of potatoes and wheat grown in a three-field crop rotation on soils with medium to highly acidic reaction of the soil solution – Chromic Luvisosl and EutricPlanosols in the study area is recommended.

Determining the sustainability of agricultural production are agro-technical activities, as the main units in any technology. A study has been carried out to evaluate the impact of crop treatment systems, mineral fertilization and integrated weed control on soil and climatic conditions in the Sofia region.
It has been found that less intensive weeding with annual and perennial weeds is observed when using a more intensive treatment system compared to the reduced treatment option. The number of weeds per unit area is increasing in the non-fertilizing variants, but their mass is lower than the fertilizers. Deeper soil tillage contributes to maintaining the values of the physical parameters (humidity, bulk density and soil hardness) in a more favorable range. Fertilization has the most significant effect on yields during the three years of the experiment.

The problem of updating agricultural technology, particularly in the field of agriculture, is important for agriculture. Alternative technology solutions that meet the performance criteria are a prerequisite for successful economic activity.
The aim of the study is to determine the effect of the application of an agro-technical complex of events, which successfully supports the soil fertility of the Planosoils and the sustainable level of productivity of the field crops.
In the field experiment in the station for irrigation agricultural Pazardzhik Valley, in three-polar crop rotation maize-barley-rape are studied three factors – soil tillage system, mineral fertilization and ways of managing plant residues.
The study found that the moisture content of the soil was mainly influenced by the type of treatment applied (loosening as a main plow and plowing as a pre-sowing) and the use of plant residues. The over compaction found in the beginning of the experiment in the 25-40 cm layer is partly overcome by performing a deep rupture to the depth of 35 cm. Despite the short period of the study, there was a certain decrease in the content of digestible potassium forms. The results show the activation of the microbiological activity after planting of the plant residues – an increase of the amount of the cellulose microorganisms and of the ammonifiable bacteria, the most noticeable in the high fertilization rate and the intensive treatments. The main part in the formation of crop rotation productivity is mineral fertilization. The impact of the tillage system is more marked in the first year of maize and especially during the third year of rape. Lack of fertilization influences yields significantly in rapeseed compared to maize and barley.