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Urban areas are characterised by land use change processes. Urban and peri-urban soils degradation increase at the different land uses, and the characteristic of each land use affecting soil carbon stock and, consequently, the role of soil as a CO2 sink. The aim of this work was to assess the effect of land use and soil management practices in urban and peri-urban soils in Vilnius (Lithuania). Studied properties were: Sand, Clay, Silt, Stoniness, bulk density (BD), pH, electrical conductivity (EC) and soil organic carbon stocks (SOCS). Ten samples were collected at depths 0-10 cm in 8 different land uses and soil management practices in the urban and peri-urban areas of Vilnius. Forests – Quercus robur, Acer plantanoides, Pinus sylvestris and Picea abies, grasslands – semi-natural grasslands (SNG) and managed semi-natural-grasslands (MSNG), both dominated by Taraxacum officinale, artificial grasslands (AG), and urban. SOC (t/ha) resulted significantly higher in Pinus sylvestris and Art. Grass than in Quercus robur, Acer plantanoides, and urban land uses. Urban land use recorded lower values of SOC (t/ha) than the other land uses except for Acer plantanoides. Land uses with high human intervention decline soil quality and affect the role of soil as a climate regulator.

The aim of the study was to determine the impact of dead organic mulches (unprocessed sheep wool - SW and ecological wool - EW), black polyethylene film (PE) and unmulched soil (WM) on the moisture regime of Hortisol and the yield of lettuce cv.´Melina´.The research was carried out at an trial field at the Faculty of Agriculture in Zagreb from April to June 2017. The experiment was set out according to a randomized block design with three replications. Soil samples were taken decadally from depths of 0-10 cm and 10-20 cm, in 3 replications, and the soil moisture content was determined by gravimetric method. The current moisture content in the soil was significantly influenced by: days after transplatation lettuce to open field (DAT) and mulch (M). The significantly low values of soil moisture were determined at 46 DAT, and high at 5 DAT. Considering the mulch, the soil moisture in both layers as follows: PE> SW> EW> WM. Diameter of the lettuce rosette was not significantly affected by the mulch type. Lettuce rosette, grown on SW (20.7 cm) was significantly higher compared to PE (18.4 cm), EW (18.0 cm) and WM (17.8 cm). The highest marketable yield of lettuce was achieved when wool mulch was applied (6.58 kg/m2 on EW, ie 6.56 kg/m2 on SW), and the lowest under PE (4.60 kg/m2). Woolen mulches have proved to be a good alternative to the previous application of PE mulches.

The variations in ground beetles (Coleoptera: Carabidae) assemblages across the three types of farmland habitats, arable land, meadows and woody vegetation were studied in relation to vegetation cover structure, intensity of agrotechnical interventions and selected soil properties. Material was pitfall trapped in 2010 and 2011 on twelve sites of the agricultural landscape in the Prešov town and its near vicinity, Eastern Slovakia. A total of 14,763 ground beetle individuals were entrapped. Material collection resulted into 92 Carabidae species, with the following six species dominating: Poecilus cupreus, Pterostichus melanarius, Pseudoophonus rufipes, Brachinus crepitans, Anchomenus dorsalis and Poecilus versicolor. Studied habitats differed significantly in the number of entrapped individuals, activity abundance as well as representation of the carabids according to their habitat preferences and ability to fly. However, no significant distinction was observed in the diversity, evenness neither dominance. The most significant environmental variables affecting Carabidae assemblages species variability were soil moisture and herb layer 0-20 cm. Another best variables selected by the forward selection were intensity of agrotechnical interventions, humus content and shrub vegetation. The other from selected soil properties seem to have just secondary meaning for the adult carabids. Environmental variables have the strongest effect on the habitat specialists, whereas ground beetles without special requirements to the habitat quality seem to be affected by the studied environmental variables just little.

The article presents the results of a comprehensive assessment of sweet potato varieties in the conditions of the Zarafshan Valley. In 2017-2019, studies were conducted on irrigated meadow-gray earth soils. Eighteen sweet potato varieties were compared. Selected variety samples were studied with a row spacing of 70 and 90 cm with a scheme of 70x25 and 90x20 cm for 1, 2 and 3 seedlings in the nest, at various irrigation regimes according to pre-irrigation soil moisture of 65-70, 70-70 and 70-80% of MWHC and the norms of mineral fertilizers (without fertilizers-control, N100P80K50, N150P120K75, N200P160K100 и N250P200K125 kg/ha). To obtain seedlings of sweet potato varieties, 40 tubers were taken and planted on February 20-22 in a film greenhouse at a temperature of 15-18 °C, seeding to a depth of 3-5 cm, the soil moisture was maintained at 65-70%. 7-10 days after planting, the buds began to germinate, and after 43-48 days, seedlings were formed with a height of 12-15 cm, which is ready for planting in the field. Planting seedlings in the field is carried out, according to the scheme 70x20-25x1 cm in the second or third decade of April. After transplanting, after 15-18 days in the field, planting care begins. Care includes - interrow processing (cultivation), weeding, weed control, top dressing, watering. Harvesting in late September, early October with a potato digger. As a result of research, varieties - Sochakinur, Xar-Bay, and Japan were identified. The cultivation of these varieties according to the scheme 70x25x1 and 90x20x1 cm with an irrigation mode according to pre-irrigation soil moisture of not less than 70-80% MWHC and the application of mineral fertilizers in the norm of N200P160K100 kg/ha contributes to a marketable crop yield per hectare of at least 48-52 tons with good qualities and good preservation. [ABSTRACT FROM AUTHOR]

The dynamics of the intensity of carbon dioxide flow from soil to a large extent depends on hydrothermal conditions. Changes in the temperature and humidity of the soil are influenced, on the one hand, by the air content and the diffusion rate, on the other - on the intensity of biological processes in the soil. The purpose of the work was to determine the patterns of influence of weather conditions on the СО2 emissionsfrom the chernozem podzolized in conditions Left-bank Forest-Steppe of Ukraine in seasonal and long-term dynamics for the period of 2012-2017. The intensity of the allocation of CO2 was determined in ventilated non stationary respiratory camera using a portable gas analyzer, with averaging results throughout the day and periodicity of observations once a month. It has been established that throughout the year the carbon dioxide emissions from the soil dynamically change depending on temperature and humidity. The maximum emission falls on the spring-summer period, the minimum values inherent in the late-autumn and winter period. As a result of the study, it was found that the intensity of carbon dioxide emissions from the chernozem podzolized during the year varies from 145 to 700 ppm. The difference between years of research illustrated the dependence of carbon dioxide production from soil from weather and climatic conditions. Under favorable weather conditions, with moderate moisture of the soil and a combination of high daily temperaturesthe production of carbon dioxide has been intensified by changes in physical and chemical processes in the soil, more active decomposition of root and fallen remains of higher plantsand the general intensification of biological processes. [ABSTRACT FROM AUTHOR]

Pythium spp. are water moulds, present in most cultivated soils, but also in natural environment. Many of them are recorded as plant pathogens of economic importance in agriculture with large range of hosts and are more devastating by causing the root rot on plants. As Oomycotes they produce sporangia which release numerous swimming zoospores. The caused diseases are more severe during an extended period of high soil moisture, or in water systems, as motile zoospores move and spread through the water to infect healthy plants. Thus these plant pathogens can spread in irrigation water as well as by contaminated soil. We have investigated the presence of Pythium species in soil samples associated with different plant hosts, derived from natural habitats or cultivated areas, and in water samples from rivers passing through diverse environments and regions in Bulgaria. Oomycotes organisms of genus Pythium were found to be largely spread across the country. Totally 22 Pythium spp. were isolated from soil samples. Among them 7 isolates were obtained from garden trade centers and forest nurseries, 10 from forests areas, 3 from orchards, one from a city park and one from a private yard. Another 20 isolates from rivers were also collected and determined as Pythium spp. according to the DNA sequencing of the internal transcribed spacer (ITS) region. Data shows the high inoculum potential of Pythium spp. present in soil and rivers throughout entire territory of Bulgaria, possible to trigger destructive plant diseases in nurseries and watering crops areas under favorable conditions. [ABSTRACT FROM AUTHOR]

The aim of our study was to investigate the temperature effects of a transit gas pipeline on soil and harvested crop over the years 2004 2006. The study area was located in the village Velk Cetn (Nitra District, South-Western Slovakia) soil type is Mollic Fluvisols calcaric. The temperature of the transported gas increased the soil temperature in the range of 1.1 to 1.75 C (average ) above the gas lines. It also reduced soil moisture by 0.07 2.67 weight per cent (average). The wheat yields above the gas pipelines decreased by 3.63 % in 2004 and by 9.53 % in 2006. Yield of barley also decreased by 13.88 % in 2005.

Soil physical properties were investigated in two types of growing systems - integrated no-till system and conventional system with ploughing, in 1999 2005 on chernozem in maize growing region. Bulk density decreased and total porosity increased during 7 years in both growing systems. In integrated system the improvement of soil physical properties could be explained by remaining of plant residues on soil surface. In conventional system the plant residues were incorporated into soil by ploughing. This led to the higher proportion of organic matter in soil. Soil cultivated conventionally had significantly higher value of reduced bulk density, significantly lower porosity and significantly higher values of soil moisture compared to soil in integrated no-till system. Maximum capillary water capacity was not significantly influenced by soil cultivation. Values of investigated soil physical properties in both systems were not markedly different from the typical values of cultivated chernozem.

The tillage systems differently affect the soil fertility and the maize yield. Irrigation is prominent cropping practice for yield increasing irrespective to fact that rain-fed is still the most broadly applied cultivation practice in the world. The aim of this study was to investigate effects of different tillage systems (conventional, reduced and no-till) and fertiliser levels on changes of the soil N content during three vegetative stages (sprouting, anthesis and harvesting), as well as maize grain yield under rain-fed and irrigation conditions in 2005-2008. The rain-fed cropping only in no-till cropping induced increase of soil moisture during anthesis. The highest N amount in soil in dry season (2008) was kept under conventional tillage in rain-fed cropping. As well, the highest grain yield was observed with conventional tillage practice. Irrigation diminished differences between cropping years and fertilization regimes.

The aim of the present work is to establish the parameters of the relationship additional yield - irrigation depth for sunflower grown in the region of Plovdiv, using different equations of the following kind: /1/ y=ax²+bx; /2/ Y=1-(1-x)n. The source data used for the study are from a field experiment, carried out in the region of Plovdiv (Bulgaria) on alluvial-meadow soil, with the sunflower hybrid PR-64-E-83. Variants of the field experiment are: 1 - without irrigation; 2, 3 and 4 - with irrigation, applying 50%, 100% and 150% of the irrigation rate, determined by the optimal variant (pre-irrigation soil moisture 75% of FC for the 0 - 80 cm layer). If we accept that the relative irrigation depth is 1.000 in variant 4, then the relative irrigation depth in the other variants is as follows: var.1 - 0.000, var.2 - 0.333 and var.3 - 0.667. The results show that equation /1/ is most suitable from a mathematical point of view. The representative type of equation /1/ is: Y=2.743x-1.745x² by R²=1. The variations of the calculated yields using this equation to experimental yields are from -10.2 to +6.8% (R=0.998). Equation /2/ is also very accurate from a mathematical point of view and at the same time corresponding well with the biology of the crop. The variations of the calculated yields using this equation to experimental yields are from -8.4 to +15.8% (R=0.993). The following parameters are established: n=3.37 (from 2.34 to 4.67) and R=0.997 (from 0.986 to 1.000). All established parameters of the relationship yield - irrigation depth in this paper are valid when moistening the 0-100 cm layer and 75% FC pre-irrigation soil moisture is maintained for the soil layer of 0 to 80 cm. [ABSTRACT FROM AUTHOR]

A new machine for surface tillage to control the aggregate composition of the soil was tested. The field trial data were processed by applying a statistical data processing software and regression equations were derived describing the fragmentation of soil aggregates of different sizes (1 mm, from 1 to 25 mm, over 25 mm) at different speeds. The regression equations are in GIS with velocity speed, current humidity and increased and decreased by 20% soil moisture. There are layers of fragmentation of soil aggregates, visualizing regression equation for units from 1 to 25 mm, to optimize the aggregate composition. [ABSTRACT FROM AUTHOR]