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.
Author: M. Mihov
Berry cultures – strawberries, raspberries, blackberries, blackcurrants, etc. are of great economic importance due to growing demand and high productivity. In general, they are susceptible to droughts and are so demanding for soil moisture, and their growth and yield depend to a large extent on the presence of sufficient soil moisture.
In order to establish the irrigation regime of raspberriesin drip irrigation conditions, field experiments were conducted on the experimental field Chelopechene-Sofia. Irrigation was carried out with a pre-irrigation humidity less than 85% of WHC and variants watered with irrigation rate reduction of 20%, 40% compared to the variant irrigated at 100% of WHC and non-irrigated variant.
Realized irrigation regimes in individual years have had an impact on the yields obtained, with the highest yields being obtained for the irrigated variants with 100% irrigation rate and the lowest in non-irrigated variants. The highest increase in yield was obtained in 2004 (dry), which is with 67% more compared to non-irrigated variants, and the smallest increase of 33% was obtained in the humid 2005.
The analysis of meteorological factors shows that the rainfall in the country is insufficient to satisfy the requirements of plants of soil moisture, and the temperature sums over ten-days periods over the whole vegetation period considerably exceed the respective norms. This requires the use of drip irrigation for the successful production of raspberries under conditions of water deficiency and relatively high temperatures.
An analysis of the state, technology and technique of the pastoral system of sheep breeding, which is best suited to the specifics of the meat sector in sheep breeding, is made.
The main types of hazards are classified for the main types of works and the conditions under which a methodological approach based on the methods of expert assessment is established to determine the significance of the different types of hazards for working in breeding sheep for meat and in breeding activities on farms .
Drip irrigation provides a fairly even mode of moisture in the soil and, along with this, favorable air, heat, microbiology and nutrition. As a result, there is an increase in yields and an improvement in the quality of production.
In order to determine the impact of drip irrigation, on the size of the yield and the economic indicators, in the cultivation of raspberries in the soil and meteorological conditions of the area of the village of Chelopechene – Sofia researches of an everbearing variety “Lyulin” were carried out. Various options have been tested – from fully satisfying the daily needs of the culture by water, irrigation with 20% and 40% irrigation norms to non- irrigating conditions.
The results obtained in years with different security of meteorological factors show that the drip irrigation of raspberries has a positive effect on the economic indicators of its cultivation, the costs of creating the raspberry crop, the irrigation system and the cultivation of the crop are redeemed for two or three years.
The intensity of aging and wear of the components /aggregates and assemblies/ of the machines is different and hence the necessity of carrying out repair service interventions has different periodicity and volume.
A model has been developed to optimize the periodicity of maintenance of machine components, taking into account the losses from the underuse of their resource.
The influence of the parameters of the law and the economic indicators on the optimal periodicity of the maintenance was examined at the density of the distribution of work until failure to the Weibull distribution.
A key element in the machinery management policy is its rational use by optimizing the periodicity of maintenance and repairs. The influence of the numerical characteristics and parameters of the reliability indicators distribution on the optimal periodicity of the maintenance has been investigated. Analytical dependencies for determining the complex reliability indicators of the objects at the optimal periodicity of the prophylactics are proposed.
The increasing water deficit requires studies to optimize irrigation regimes and water-saving technologies to achieve economy of irrigation water at an acceptable yield level.
In order to establish the irrigation regime in the field of “Chelopechene” Experimental Field, Sofia, there have been researches, examining different regimes – from full satisfaction of the daily needs of culture for water to irrigation with reduced by 20% and 40% water application rates.
On average, over the survey period, the highest yields were obtained with the irrigated wit 100% water applicatipn rate. Reducing the irrigation rate leads to a corresponding reduction in yields and affects the quality of production. The application of regimes of irrigation with reduced iwater applicatipn rates is recommended only in the case of water deficiency.
CONSERVING OF THE RESOURCES
To determine the effect of magnetically treated seeds on the productivity of tomatoes and onion in the area of the Sofia field experimental experiments were carried out with variants with magnetically treated seeds and variants without magnetic treatment of the seeds. Irrigation has been dripped in optimum irrigation mode. The yields obtained with the processed tomato seeds in tomatoes are up to 22% higher than those of untreated and onion onions to 28%, respectively.
MECHANIZATION IN AGRICULTURE
The system of the servicing of the machines in the livestock farms has been analyzed and the necessity of optimizing the spare parts services and the scope of the workshops for maintaining the equipment in the livestock breeding. Relations have been developed to optimize the area to be serviced by the workshop and its spare parts warehouse, as well as the optimal average distance to be found from where machines work.