Table of Contents

  • Application of electronic systems for control and navigation in agriculture

    pg(s) 146-157

    The agricultural machines become more and more complex and complicated systems aimed to produce cheaper and plenty of agricultural products. The modern farmers uses computer technology and equipment not only for monitoring and analysis of the financial results from his activity, but also for expert assessment of yields, state of soil, crops, animals, machinery, product parameters, climatic conditions. Being acquainted with the principles of operation, structure, parameters and modes of adjustment and work with such electronic systems is becoming an obligatory part of the training of agricultural production experts.

  • Methodology and results of experimental studies of combined unit for sugar beet tops harvesting on the basis of a row-crop tractor

    pg(s) 158-161

    On the basis of an integrated wheel-type tractor (traction class 3.0), there was created the new combined machine and tractor unit carried out a continuous flat cutting of the sugar beet tops with a front mounted sugar beet tops cutting machine. To carry out this field experimental studies, a program and methodology was developed based on measurements of the remains of the tops on the heads of root crops after passing through the aggregate at a given rate of translational motion, the height of the installation of its rotary cutting mechanism above the level of the soil surface and the frequency of its rotation. The results of the study were statistically processed on a personal computer using regression and correlation analysis methods. Based on the developed methodology of the full-factor experiment, empirical mathematical models were constructed in the form of regression equations for the process of cutting the tops of sugar beet. According to the results of these calculations, it was found that the speed of the forward movement of the sugar beet tops cutting aggregate exerts the greatest influence on the mass of the remains of the tops on the spherical surfaces of the root heads, after a continuous main cut. In a lesser extent, this process is influenced by the rotational speed of the rotor of the sugar beet tops cutting machine and the height of the rotor installation above the soil surface level by means of two pneumatic copying wheels. According to the results of experimental studies, it has been established that the rational design and technological parameters of the process for harvesting sugar beet tops by a front mounted sugar beet tops harvesting  machine with a rotary cutting apparatus is its rotation frequency equal to 960 rpm, the speed of the aggregate should not exceed 2.0 m.s-1, and the height of the rotor installation should be as low as possible, not less than 0.02 m.

  • Sustainable innovation technology: An insight into the effective use of biofertilizers in improving soil and plant quality

    pg(s) 162-164

    The employment of inorganic fertilizers to overcome soil nutrient deficiency causes the depletion of microfloral diversity in the soil. Hence, there is a necessity to implement different eco-friendly strategies to maintain the nutrient level. In a series of experiments funded by SITINPLANT European Project, we have previously determined the interaction between the mycorrhizae and antagonistic biocontrol micro-organisms and their effect on diseases and plant nutrient uptake of several plants and trees. On the basis of the inferences obtained from that project, we are presently working on the utilization of mycorrhizal fungi and bacteria as organic fertilizers (i.e. biofertilizers) for wheat development. Our specific aim is to determine the strategies that may support to decrease the usage of commercial P fertilizers. The results of these experiments will provide an insight into the effective usage of different microorganisms for improving crop productivity and increasing food security.

  • New plant growth stimulator – humatphosphate

    pg(s) 165-167

    The results of vegetative and field tests of the new plant growth stimulator – humatophosphate in various agricultures are presented. It is shown that humatophosphate exerts a strong influence on the growth of the root system of plants, on the formation of the leaf surface, increases the number of fruits and improves the commercial quality of the fruit.

  • Ecological and economically effective agriculture through creating energy levels of soil moisture in fields

    pg(s) 168-171

    The report deals with the perspectives for developing ecologically based biological agriculture in Bulgaria, the European Union and the other countries. Innovative technology (for computerized monitoring the soil water deficit and scheduling the irrigation) replaces the periodical local (point) measurements of soil moisture. Its application helps to be taken into account the physiological features of crop, creating appropriate energy level of soil moisture through ecologically accepted watering technique in each agricultural crop field. It ensures to be obtained the scientifically planned amount and quality of crop yield, saving on average 30 % of irrigation water and one third of nutrients added for plants.

    New universal estimation of crop water status, current computerized monitoring of the water deficit in root zone of soil, and exact management of productivity are possible to be accomplished.

    Data were obtained under field conditions over 30-year research period. Fundamental physical laws and recent Bulgarian and foreign world-top scientific achievements were aggregated and applied to be created the new scientific basis of the technology.

    The obtained results showed the successful applications of: (a) the new hydro-physical index and the method for its determination under both non-irrigation and irrigation conditions and (b) the Technology for Monitoring, Estimating and Managing (TMEM) of the water status of this layer in irrigation rural activities, taking into account the European ecological requirements. The technology is easily applied as Decision Support System (DSS) in irrigation agriculture.

  • Impact of green manure and straw on biogenic elements leaching in Luvisol

    pg(s) 172-174

    The paper presents summarized results of lysimetric experiments intended to determine the impact of green manure crops and straw on chemical elements leaching (N, K, Ca, Corg) and of atmospheric precipitation infiltration in sandy loam Luvisol. Lysimeter surface area is 1.75 m2, the test soil layer is 0.60 m. It was determined that under climatic conditions of Lithuania, cover crops for green manure reduce atmospheric precipitation infiltration in sandy loam soil during autumn, and the effects of nutrient leaching depend on the plant species. Fabaceae plants clover (Trifolium pratense L.) stimulate nitrogen leaching, while Poaceae orchard grass (Dactylis glomerata L.) and Brassicaceae fodder radish (Raphanus sativus L.) lessen it. Incorporation of green manure biomass does not alter potassium and calcium leaching, but substantially reduces the organic carbon leaching.

  • Prioritizing of soil and water resources management scenarios using multi-criteria decision making technique

    pg(s) 175-177

    Watershed sources management is considered as a new principle for development planning and management of water and soil resources emphasizing on various criteria of the region to sustainable livelihoods and without vulnerability of plant and the residents of an area. Aiming at management of soil and water resources with scenario building approach, current study has evaluated and prioritized biological management options in the study area. With a choice of four biological management activities, scenarios were developed and then criteria weighting and ultimately the best management option selection was carried out using analytic hierarchy process (AHP). The results indicated that social, ecological, economic and physical criteria were respectively prioritized from one to four and scenario number 16 was identified as the best scenario and the first priority.

  • Hydrometric monitoring of rivers in conditions of ehtreme phenomena-methodical and tehnological inovations

    pg(s) 178-181

    High water levels in the conditions of extreme events are a characteristic phase of the river runoff in the order of several hours passing huge volumes of water. The drainage is characterized by turbulent state, significant velocities and depths, which change rapidly and cause pronounced uneven and unsteady process. Water quantities may exceed a few hundred times their annual average, causing large spills in river valleys, and the deep depth and dragging force of the stream are a natural disaster causing huge damage with the possibility of human casualties.

  • Water purification from different pollutants by activated carbons

    pg(s) 182-183

    Nanoporous activated carbons were prepared by hydropyrolysis processing from various biomass precursors – apricot stones, been pods, bamboo, etc. The obtained carbon adsorbents are distinguished with moderately high surface area and prevailing microporous structure. Their properties determine their application as effective adsorbents for removal of organic (phenols, etc.) and inorganic pollutants (metal ions, etc.).