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

To determine the total and average evapotranspiration of pears during its cultivation under soil and meteorological conditions in the area of the village of Chelopechene – Sofia, studies were conducted on drip irrigation (KP-4.6 drip trays) of pear plantation of the variety “Hardenponova maslovka”.
Meteorological conditions during the study period influenced the size and daily average values of culture evapotranspiration.
The total evapotranspiration for the pear growth period of 536 mm was determined, and the daily values of biophysical coefficients Z, R and Kp were calculated for practical use and design, which depend on the biological features of the crop and the meteorological factors.

To establish the totals and average daily evapotranspiration of raspberry under the soil and climate conditions in the village of Chelopechene, near Sofia city research was conducted with drip irrigation of plantations with variety “Lyulin” adopting varying irrigation schedules – from fully meeting the daily crop water requirements to reduced depths with 20% and 40%.
The meteorological conditions during the study period have been influenced by the totals and average daily On average, during the research period the magnitude of the total evapotranspiration for the vegetation period of the raspberry is 482 mm, with the highest values reaching 592 mm in the dry 2000.
For the needs of the practice and the design are calculated also the ten-day values of the biophysical coefficient Z and kb, which depend on the biological characteristics of the culture and the meteorological factors.

Experimentally, the evapotranspiration and evaporation from the free water surface of long-fruit cucumbers grown under greenhouse conditions was established. Based on the calculated values of the evapotranspiration based on the soil humidity dynamics data during the vegetation period, the irrigation carried out and the evaporation from the free water surface determined by a class “A” evaporator, the values of the coefficient of the culture in unheated plastic greenhouses were calculated as an average for the vegetation process of cucumbers Ki is 1,46. Establishing a correlation between ET and Eo under greenhouse conditions allows a safer use of Class A evaporator data.

The evapotranspiration of Gergana long-fruit cucumbers was established in four years of field experimentation with drip irrigation, grown in greenhouse conditions on chromic luvisol soil in the Sofia region. Different irrigation regimes have been tested – from full satisfaction of the daily needs of the culture from water to irrigation with 20% and 40% reduced water application rates. The total evapotranspiration values for the study period were determined.
For the needs of practice and design, the ten-day values of the biophysical coefficient Z are calculated, which depends on the biological characteristics of the crop and the weather factors. On the basis of the established relationship between evapotranspiration and evaporation, the values of the coefficient of crop in unheated plastic greenhouses are calculated as the average for the cucumber vegetation curve Ki = 1.46.

In order to establish the aggregate and average daily values of raspberry evapotranspiration in an experimental site in the village of Chelopechene – Sofia, drip irrigation studies were carried out on a replanting variety "Liulin" under different irrigation regimes – from full satisfaction of the daily needs of the culture from water to irrigation with 20% and 40% irrigation norms. The meteorological conditions during the study period showed an influence on the sum of the sum and day-to-day values of the culture evapotranspiration.

On average, during the research period, the total evapotranspiration rate for the raspberry vegetation period is 4730 m3 / ha, with the main part being formed by the irrigation rate – 60% and by rainfall – 40%

For the needs of practice and design, the ten-day values of the biophysical coefficients Z and Kp were calculated over a five-year period.