The analysis of meteorological data from the period 1961–2014 show the rise in the mean annual temperature in the entire territory of Bosnia and Herzegovina. The changes are more pronounced in the central – hilly part of the country. The increase in annual air temperature ranges from 0.4 to 1.0°C per decade, whereas temperature increases during vegetation period were up to 1.2°C per decade. Additionally, increases in air temperature over the last fourteen years are even more pronounced. Changed distribution of precipitation, significant variations and the increasing soil moisture deficit during vegetation period (April – September) are also evident in Bosnia and Herzegovina. The increase in air temperature combined with changes in the distribution of precipitation has resulted in a change of evapotranspiration and annual water balance. The main objective of this study was to determine and compare the severity of changes in mean annual water balance components between different regions in Bosnia and Herzegovina. Monthly weather data from 26 weather stations in Bosnia and Herzegovina, for the time period of 50 years (1967 – 2016) were used to determine and analyze impact of climate change on the following water balance components: temperature, precipitation, reference evapotranspiration, actual evapotranspiration, total runoff, soil moisture deficit and amount of snow. The results indicate that climate change has a substantial effect on the all water balance components. Air temperature (0.21 - 0.7 o C per decade), reference evapotranspiration (0.61 - 42.81 mm per decade) and soil moisture deficit (1.35 - 27.71 mm per decade) show an increasing trend over the entire territory of Bosnia and Herzegovina with the strongest increase in the north-west part of the country.
Conservation tillage is expected to have a positive effect on soil physical properties, soil Carbon (C) storage, while reducing fuel, labour and machinery costs. However, reduced tillage could increase soil nitrous oxide (N2O) emissions and offset the expected gains from increased C sequestration. To date, conservation tillage is barely practiced or studied in Bosnia and Herzegovina (BH). Here, we report a field study on the short-term effects of reduced (RT) and no tillage (NT) on N2O emission dynamics, yield-scaled N2O emissions, soil structure and the economics of cereal production, as compared with conventional tillage (CT). The field experiment was conducted in the Sarajevo region on a clayey loam under typical climatic conditions for humid, continental BH. N2O emissions were monitored in a Maize-Barley rotation over two cropping seasons. Soil structure was studied at the end of the second season. In the much wetter 2014, N2O emission were in the order of CT > RT > NT, while in the drier 2015, the order was RT > CT > NT. The emission factors were within or slightly above the uncertainty range of the IPCC Tier 1 factor, if taking account for the N input from the cover crop (alfalfa) preceding the first experimental year. Saturated soils in spring, formation of soil crusts and occasional droughts adversely affected yields, particularly in the second year (barley). In 2014, yield-scaled N2O emissions ranged from 83.2 to 161.7 g N Mg-1 grain (corn) but were much greater in the second year due to crop failure (barley). RT had the smallest yield-scaled N2O emission in both years. NT resulted in economically inacceptable returns, due to the increased costs of weed control and low yields in both years. The reduced number of operations in RT reduced production costs and generated positive net returns. Therefore, RT could potentially provide agronomic and environmental benefits in crop production in BH.
Drought in Bosnia and Herzegovina (B&H) is mostly analyzed using water deficit obtained from agro-hydrological balance; a ratio between precipitation or actual evapotranspiration (AET) to potential evapotranspiration (PET); and more recently using Standardized Precipitation Index (SPI). The main objective of this research is to use the relatively new multiscalar drought index, Standardized Precipitation Evapotranspiration Index (SPEI) to analyze severity, magnitude, and duration of drought periods in B&H. SPEI is based on precipitation and evapotranspiration data and it has the advantage of combing multiscalar character with the capacity to include the effects of variability in atmospheric water demand on draught assessment. Evapotranspiration is calculated with Penman-Monteith method, the standard international procedure for computing reference or potential evapotranspiration (ET0). In order to assess all four types of drought, SPEI is calculated for shorter (1, 3 and 6 months) and longer (12 and 24 months) time scales. Weather stations with long-term continuous climate data records were selected 13 stations across B&H in total, from which the climate data for 50-year period (1961 – 2010) were collected. A crucial advantage of SPEI over other drought indices previously used in B&H and its use of potential evapotranspiration and multiscalar characteristics, enabling identification of different drought types. By using Standardized Precipitation Evapotranspiration Index (SPEI) it was found that severity, magnitude and duration of drought periods in B&H vary depending on the location and time scale for which drought was calculated. Presence of more severe long lasting droughts in period after 1986 was found for all 13 analyzed locations across B&H.
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