**Author details**

*Agrometeorology*

**4. Conclusions**

The presented study is essential for a series of studies within the cited National Science Program and its project - Agricultural Ecosystems - adapted to climate

1.The values of the parameters of the climate change for the agricultural zone of the country during the studied period 1986-2015 for 56 meteorological and

2.The sign and the amount of the deviations in the agricultural areas of the average multi-annual monthly values of the temperatures and the monthly amounts of the precipitation for the period 1986-2015 compared to the refer-

3.The data obtained show larger positive values of the temperature deviations in January, February, July, August and September and negative values of these

4.In case of precipitation - the positive and negative deviations by months are small in value, with the exception of Obraztsov Chiflik and Plovdiv. The nonuniform nature of the distribution of precipitation by seasons increases and dry winters, dry beginning of spring, rainy June and prolonged 70-90 days of summer drought, followed by wet October and November, become more frequent. These features of the climate are a serious challenge for specialists in genetics and selection in creating varieties that can withstand periods of

5.The average long-term values of active and effective temperatures for the periods with t ≥ 5**°**C and t ≥ 10**°**C are obtained, which in most regions of the country are 3500-4000**°**C respectively and over 1500-2500**°**C respectively. This is a sure indication that thermal conditions are not a limiting factor and allow the cultivation of second crops, as well as the introduction of tropical crops

6.The in-depth analysis of the hydrothermal conditions is a prerequisite to

production under natural conditions of humidification of soils.

**and Quality of Life** approved by DCM 577/17.08.2018.

recommend, over the next 5 years, a gradual but large-scale increase in investments for the construction of modern irrigation systems. The results of the climate scenarios for the next 20-30 years show the tendency of the observed changes to continue, which will make impossible the efficiency of agricultural

This work was supported by the Bulgarian Ministry of Education and Science under the National Research Program - **Healthy Foods for a Strong Bio-Economy** 

change. The main results for this stage of project development are:

agrometeorological stations are obtained;

ence period 1961-1990 have been determined.

deviations in December.

with a short growing season;

drought;

**Acknowledgements**

**54**

Valentin Stoyanov Kazandjiev\* and Veska Anastassova Georgieva National Institute of Meteorology and Hydrology, Sofia, Bulgaria

\*Address all correspondence to: valentin.kazandjiev@meteo.bg

© 2020 The Author(s). Licensee IntechOpen. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/ by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
