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

To establish the influence of different irrigation and fertilization rates on the quality indicators of the fruit of three specific genotypes of tomatoes- Maldo, Pink Rock, and Hayet- in 2022, experiments were conducted in the experimental field of Maritza Vegetable Crop Research Institute – Plovdiv in an unheated steel and glass greenhouse type Venlo. The experiment was conducted under three irrigation regimes – optimal, reduced, and increased irrigation – 100%, 75%, and 125% using water-saving irrigation technologies and three fertilization regimes – optimal, reduced, and increased fertilization – 100%, 75%, and 150%.
It was found that reducing the water content resulted in a slight increase in dry matter, total soluble solids (TSS), and vitamin C content while varying the fertilizer rate did not significantly change the studied characteristics. Tomato fruit quality was more affected by irrigation than by fertilizer levels. Titratable acidity and pH differed between cultivars but not between treatments applied. The highest dry matter, TSS, and vitamin C contents were observed in the treatments with low irrigation rates and optimal fertilization (75%W and 100%F). Strong positive correlations were found between dry matter, TSS and vitamin C, while a strong negative correlation was found between fruit firmness and dry matter, TSS and vitamin C.
The factor Genotype had the strongest effect on the tomato fruit quality parameters studied, with a weaker but proven effect of the individual factors irrigation rate and fertilization rate on dry matter, soluble solids content, and vitamin C. The highest fruit quality was found in Pink Rock, followed by Maldo. The variety with the lowest values for most of the quality indicators is Hayet.

To establish the influence of irrigation and mineral regime on the growth index of tomatoes, the irrigation and fertilization schedules of three genotypes of tomatoes grown in an unheated steel and glass greenhouse in an experimental field of MVCRI – Plovdiv, Bulgaria, were examined. Environmentally friendly and water-saving irrigation techniques were used. Different irrigation rates were applied starting from full satisfaction of the crop water requirements to irrigation and with 25% reduction and 25% increase in irrigation rates and three fertilization rates respectively – optimum with 25% reduction and 50% increase.
After processing the results, the growth index showed an increase in the irrigation rate by 25% above the optimum growth in all three tomato cultivars included in the experiment. At the same time, no such relationship was observed when the fertilization rates were changed. The exception was the cultivar ‘Hayet,’ in which a decrease in fertilizer rate was also associated with a higher growth index, close to that of the optimum fertilizer regime. At the same time, the combination of increasing or decreasing the irrigation rate and fertilization did not have a positive effect on growth.

In order to determine the influence of different rates of irrigation and fertilization on the growth, yield, and some yield-related characteristics of three genotypes of tomatoes, research was carried out at IVCM – Plovdiv in an unheated steel-glass greenhouse of the “Venlo” type. The experiment was carried out with three modes of irrigation: optimal – 100%, reduced – 75%, and increased – 125%, using water-saving irrigation technologies and three modes of fertilization – optimal – 100%, reduced – 75%, and increased fertilization – 150%. The amount of watering and irrigation norms, the number of waterings for the growing season of greenhouse tomatoes were determined based on soil type, and climatic conditions in the region of Plovdiv. An optimal or high irrigation rate combined with reduced or optimal fertilization leads to maximum yields in all three tomato varieties. A specific reaction of the variety was observed – in “Hayet” and “Pink rock ”varieties, maximum yields (14.1 t/ha and 8.8 t/ha) were obtained in the variants with 100%/75%, while in the “Malduo” variety, the highest yield was obtained (8.6 t/ha) in the variant with 125%/100%, irrigation/fertilizer rate. In the three studied varieties of tomatoes, the lowest yield was reported when the irrigation rate was reduced by 25%, which shows that the reduction of the irrigation rate by 25% is within the limits of the critical, while the reduction of the fertilizer rate by 25% is permissible.

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.

The technological process of unmanned aerial vehicles (UAV) application in the system of precise farming includes sequential interrelated operations: monitoring and sounding of crops (using light UAVs equipped with multispectral cameras), obtaining, processing and transmitting information for crop management, differentiated application of pesticides and fertilizers according to a specified treatment program (UAV through a large payload).