• Studies to establish evapotranspiration and biophysical coefficients of pears grown in drip irrigation

    pg(s) 190-192

    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.

  • Analysis of climatic variability and determination of thermal and pluviometric limits in Albania’s Southwestern Lowland Area (Vlora)

    pg(s) 184-189

    The geographical distribution of plants in ecosystems and the limits of agronomic extention of plants cultivated in different areas are conditioned by the performance and climatic variabilities of these areas.The biological and productive behavior of plants in agricultural systems is determined by climate performance in general and in particular by the two main climatic parameters, temperature and precipitation.Their significant fluctuations, conditioned in recent years by climate change, are evident in the form of risky for agriculture such as prolonged droughts, severe shortages of rainfall, high summer temperatures in the form of heat waves, which further brings the effect of agronomic drought. In the thermal minimums, expressed in the form of frosts, there are observed fluctuations changes creating deviations from the average perennial performance of their occurrence. The study of thermal fluctuations, and in particular the study of the phenomenon of drought and its consequences, it is an important problem especially in areas with high agricultural character. Drought occurs when there is a shortage of rainfall for long periods, registering as a pluviometric deficit. Occurrence variations of this phenomenon are related to the rainfall cycle, but they should be considered in relation to potential climate change, especially in the Mediterranean basin where Albania is located. The study of climate variability and the identification of extreme climate phenomenas as well as the determination of thermal and pluviometric limits can be done through climate monitoring indicators. Albania’s western lowland area and particulary the Vlora area, which is under consideration on this study, is an agricultural area with a great diversity of cropping cultivations. Analyzing the climate behavior of this area will enable the design of suitable cultivation technologies as well as taking measures to minimize the damages to crop production from these factors.

  • Study of the influence of the irrigation regime on the quantity and quality of tomatoes grown in plastic greenhouses

    pg(s) 181-183

    To establish the influence of the irrigation regime on the quantity and quality of tomatoes grown in plastic unheated greenhouses, research was conducted in the experimental field of the Pushkarov Institute in Chelopechene, Sofia. Different irrigation regimes have been tested, keeping from fully satisfying the needs of the crop from water to irrigation with a 20% reduction and a 20% increase in irrigation norms. The control variant is irrigated at 100% realization of the irrigation norm, calculated by (E0) evaporation from a free water surface by an evaporator class “A”.
    It has been established that the reduction of the irrigation norm due to the limited water supply leads to a corresponding reduction of the yield, which is not proportional to the reduction of the irrigation norm.
    The quality of the obtained production – tomatoes determined by the content of dry matter, vitamin “C” and total sugars deteriorates with increasing amount of irrigation rate.

  • Water – yield relationships of lettuce plants for different irrigation strategies

    pg(s) 177-180

    The greatest fresh water user sector is agriculture worldwide. The optimum utilization of current water supplies is necessarily prerequisites particularly in water poor climates. It is almost impossible to obtain economical crop yield without irrigation in those types of environments. In general, vegetables are high water consuming crops and well responses to the adequate soil moisture levels in rooting depths. Correct irrigation program is vital important for reaching target optimal production. The present study aimed to analyze irrigation programs affect on yield and water use efficiency, WUE, of lettuce plant for different growing conditions. In accordance of previous studies, maximum yield was obtained from full irrigation treatment. Lettuce plants were not tolerant wide irrigation intervals e.g. 2 or 3-day ideal for optimal yield and quality. Evapotranspiration, ETc, was highly dependent on lettuce varieties, availability of soil moisture content in root systems as well as climatological factors, and ranged between 413 mm and 208 mm. The planting geometry also had effect on lettuce yield. The irrigation system is important, but the most important issue is proper water management for enhancing crop production. Use of sprinkler or drip irrigation system should be highly recommended for better yield, quality as well as efficient water usages or water savings in vegetable farming under correct irrigation program.

  • Growth analysis of sweet pepper for investigation effect of wood ash and poultry litter on plant

    pg(s) 173-176

    The present study uses the method of soil crops to study the fertilization of the soil, changes in the content and forms of nutrients, the effectiveness of various forms of nutrients introduced by the resulting of soil improver – a mixture of waste – wood ash and poultry litter, by means of a vegetation experiment. Sweet pepper Capsicum annuum subsp. macrocarpum L. was selected for the experiment, variety of gate type – Gold medal 7. The results of the study prove the ability to use soil improvers, good resistance of the leaves to sudden intense changes in climatic conditions. The root systems of all mixtures are well developed and strong, stable with good agrochemical parameters compared to that of the zero sample.

  • The influence of long-term agricultural use of soils of the dry subtropical zone of Azerbaijan on its morphological and agrochemical properties

    pg(s) 169-172

    The aim of the research was to study the influence of natural vegetation and intermediate sowings of fodder crops on the formation in the profile of (WRB, 1998) Gypsisols and Gleyic Calsisols and Irrigated Gypsisols and Gleyic Calsisols soils of the dry-steppe and semi-desert zones of Azerbaijan genetic horizons. It has been established that significant morphological changes are common to the thickness of the humus horizon, the depth of carbonates and agrochemical parameters of the studied soils. Their maximum values in the arable layer are established in Irrigated Gypsisols and Gleyic Calsisols soils under the collection of 3 green mass crops per year from 1 ha: the thickness of the humus horizon increased to 0.25 and 0.27 cm, respectively, humus – up to 2.73 and 3.00%, the amount of absorbed bases – up to 25.71 and 30,80 mg-eq / 100 g of soil, mobile phosphorus – up to 30.9 and 34,00 and exchange potassium – up to 317.3 and 423,1 mg / 100 g of soil. In accordance with the WRB system (2015), Irrigated Gypsisols can be classified – Irragric Cambisols (Protocalcic, Clayic), and Gleyic Calsisols – Irragric Gleyic Calcisols (Calcic, Loamic).

  • Assessment of chemical composition of soil solution of water repellent soils from Maritza- Iztok coal basin

    pg(s) 166-168

    The ionic composition and dissolved organic carbon (DOC) in soil solution of four soil profiles, from the area of Obruchishte were analyzed and relationships with soil hydrophobicity were discussed. It was found that the greatest variation and leaching of NO3-, SO4 2-
    and Ca2+ were from the profile of Obruchishte under ash, while of Na+ from Obruchishte under pine. In Obruchishte profile after cereals the highest content of Cl-, PO43- and NO3- were found in the investigated soil solution. No significant correlation was found between the chemical elements and WDPT, except for Obruchishte, stubble. In this profile a significant correlation was found between the Ca2+ and Mg2+ concentrations and WDPT. Significant relationship (R*=0.63, p<0.05) between DOC and WDPT was established only at the experimental profile Obruchishte under ash. Differences in the distribution of soluble organic carbon in soil profiles in our studies is most likely due to the heterogeneity of the geological materials used as a substrate for reclamation of the studied sites

  • Water productivity and the effect of watering on apples grown under conditions of optimal irrigation and water deficit

    pg(s) 150-153

    In order to determine the productivity and the effect of irrigation on apples grown under soil and meteorological conditions in the area of the village of Chelopechene – Sofia, research was conducted on drip irrigation of a plantation of the “Florina” variety, and different regimes were tested – from complete satisfaction of the daily needs of water to irrigate the culture with irrigation rates reduced by 20% and 40%. A non-irrigation variant has also been tested.
    The productivity of the irrigation rate at optimal irrigation varies by years from 16.3 to 28.0 kg.ha-1.mm-1, and at 40% reduction of the irrigation rate from 19.3 to 26.0 kg.ha-1. mm-1
    The highest values of productivity of the irrigation rate are reached at irrigation with a 40% reduction of the irrigation rate, in the dry 2004 high values were obtained and at the variant irrigated with 100% irrigation rate 28,0 kg.ha-1.mm-1
    The optimization of moisture in the active soil layer contributes to a significant increase and stabilization of yields, which for the test conditions are from 1266 to 2087 kg / dka. Additional yields ranged from 542 to 821 kg / dka, averaging over the study period.

  • Changes in the agrochemical status of Haplic Vertisols depending on the agro-technical measures

    pg(s) 146-149

    By assessing basic agro-technical factors, optimal decisions can be made for good agricultural practice on soils with heavy mechanical composition, such as the Haplic Vertisols.
    The aim of the study is to identify the changes in the agrochemical status of Haplic Vertisols that occur under the influence of applied agro-technical measures.
    For the achievement of the purpose in the period 2016 -2019, a field trials, based on the block method in the Sofia Region on a Haplic Vertisols were carried out.
    The applied fertilization mainly affects the content of nitrate and ammonium nitrogen, the phosphorus forms remain with low values, it is clearly necessary to raise the norm and with a methodical approach it is necessary to achieve a sustainable level of absorbed phosphates. The content of the absorbed potassium is still satisfactory, and based on the data from the analysis, its reduction and export with the produced products are smaller.

  • Effect of the implementation of agro-technical and ameliorative measures in soils with poor technological and pedological properties

    pg(s) 140-145

    Applying appropriate tillage systems, agro-technical and ameliorative measures can stop the negative changes in soil functions and stabilize and improve soil fertility through a systematic agro-technical approach.
    The aim of the study is to investigate the effect of the introduction of new solutions in agro-technology on cultivation of arable crops on soils with impaired fertility. In a three-field crop rotation with potato, wheat and corn cultivation, after the application of soil tillage and liming systems, it has been found that soil tillage systems have a direct and indirect impact on the productivity of crops grown under crop rotation, setting the conditions for the cultivation of crops other agrotechnical activities.
    The deeper basic cultivations applied to the potatoes on Chromic Luvisosl and EutricPlanosols, leads to lower values of bulk density and strength.
    Potato cultivation has a significant effect on both limestone and ash input, with a positive effect on corn and wheat.
    On the basis of the results obtained from the field experiments, a technology for the production of potatoes and wheat grown in a three-field crop rotation on soils with medium to highly acidic reaction of the soil solution – Chromic Luvisosl and EutricPlanosols in the study area is recommended.

  • Approaches for reclamation of embankments from the extraction of polymetallic ores with soil improvers from waste and R. acetosella, and R. patientia

    pg(s) 136-139

    The present study examines the possibilities for reclamation of soils contaminated with heavy metals from the extraction of polymetallic ores with soil improvers mixture of waste – sludge from WWTP and ash from thermal power plants, through a vegetation experiment. Two herbaceous species of the genus Rumex were selected for the experiment – R. acetossela and R. patienta known for their ability to accumulate heavy metals and in particular copper. The results of the study prove the ability to use the improvers in biological reclamation of old embankments.

  • Physico-chemical properties of lignite mine reclaimed soil formed under 19 different tree species in Sokolov, Czech Republic

    pg(s) 134-135

    Coal mining was, and still is, a very important part of Czech national economy. Since 1957, it has been compulsory for organizations which have been granted mining permissions to carry out restoration procedures after the mining is finished. The aim of this research was to compare the physico-chemical properties of reclaimed mine soil of Antonin locality in the Sokolov mining basin, Czech Republic, which was experimentally afforested between 1968 and 1972. 5 undisturbed soil samples were taken from each of the 20 homogeneous stands (100 samples in total) composed of 19 various tree species (10 broadleaved and 9 coniferous) and bulk and specific density, porosity, water retention capacities, pH, soil oxidizable carbon (SOC) and total levels of N, C and S were determined and compared. In most cases, forming of soils with better overall physical and chemical properties was noticed under the broadleaved species.