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The process of climate warming significantly affects agroclimatic resources and agricultural production. We study the agroclimatic resources and their variability on the territory of the Republic of Bashkortostan (Russia). The Bashkortostan has a high agricultural potential and holds a leading position in the country in the production of grain crops, potatoes, milk, and honey. Currently, no detailed studies have been conducted for this area to assess the effects of global climate change on agro-climatic resources. World experience shows such research becomes strategically important for regions with powerful agricultural production. We used the sums of average daily air temperatures above 0 and 10 °C, the G.T. Selyaninov hydrothermal coefficient, and the Ped aridity (humidification) index as agroclimatic indicators. We used data of long-term meteorological observations of 30 meteorological stations for the period of 1961–2020. We revealed the long-term dynamics of the agroclimatic indicators and the spatial and temporal regularities in their distribution on the territory of Bashkortostan. There is a steady increase in the sums of average daily air temperatures above 0 and 10 °C. Against this background, aridity increases, which is especially manifested in the southern parts of the Republic of Bashkortostan. We assessed the impact of agroclimatic indicators on the main types of agricultural crops in the republic. We revealed that the greatest positive impact on the yield of oilseeds, cereals, and industrial crops is made by precipitation at the beginning (r = 0.50, r = 0.44, and r = 0.52, respectively) and in the middle of the growing season (r = 0.55, r = 0.76, and r = 0.51, respectively). Temperature and precipitation during the growing season have a complex effect on cereals. This is proven by correlations with HCS and the Ped index (r = 0.45 and r = −0.56, respectively). Aridity at the beginning of the growing season affects the yield of oilseeds and potatoes. This is confirmed by correlations with the Ped index (r = −0.49 and r = −0.52, respectively). In general, the aridity of the growing season has a significant impact on the yield of cereals (r = −0.57). Negative relationships have been found between the air temperature growing season and the yield of potatoes (r = −0.50) and cereals (r = −0.53). The results of the study were compared with data from the Copernicus Climate Change Service database. We identified climate trends under RCP 2.6, RCP 4.5, RCP 6.0, and RCP 8.5 scenarios. These scenarios should be taken into account when developing plans for the adaptation of agriculture in the Republic of Bashkortostan to changes in the regional climate. Maximum decrease in precipitation is established for the RCP 6.0 scenario. This can have an extremely negative impact on crop yields. This problem is especially relevant for the southern part of the Republic of Bashkortostan. The information presented in the study will allow for a more effective adaptation of the agricultural sector to current and future climate changes. [ABSTRACT FROM AUTHOR]

The morphological, water-physical and chemical properties, basal respiration of the southern chernozem (Chernozem Haplic Endosalic) and erosional sediment in the Trans-Ural steppe zone (Republic of Bashkortostan, Russia) were studied. The surface soil horizon significantly differs from the sediment by the better structure and water aggregate stability. The particle size distribution of the sediments, due to erosion, contains more silt and clay fractions compared to the slope soil. It indicates a great potential for the carbon saturation of the soil which is limited by degradation. The slope soil is slightly saline, the type of the salinisation is sulfate with the participation of hydrocarbonates. The СО2 emissions, the organic carbon and alkaline-hydrolysable nitrogen content is low; and significantly lower than in the erosional sediment, but the content of exchangeable cations and water-soluble salts is higher. The structural composition of the humic acid (HA) extracted from the soil and erosional sediments was determined by 13C NMR spectroscopy. Aliphatic structural fragments predominate (65%) with a maximum signal level in the area of C, H-alkyls in the HA of the surface horizon. In the HA of the erosional sediment, the proportion of aromatic structural fragments is higher (up to 59%), which is associated with the processes of hydrolysis and condensation. In the HA of the slope soil, the formation of predominantly C, H-alkyls, oxygen-containing groups, including carboxyl ones, takes place. Differences in the composition of the structural fragments and functional groups of the soil and sediment HA are due to the different stability of the organic matter under conditions of the development of the soil erosion processes. [ABSTRACT FROM AUTHOR]

In the present study, we evaluated the effects of surface application and plowing of phosphogypsum and turkey litter to a depth of 20 cm on the erodibility of clay-illuvial agrochernozem (Luvic Chernozems (Aric, Pachic)) in the Southern Cis-Urals (Republic of Bashkortostan, Russia). Under laboratory conditions, 1°, 3°, and 7° slopes were modeled. Soil loss, runoff onset time, and turbidity were measured with a rainfall simulator. Particle size distribution and total organic carbon were measured. Under simulated heavy rainfall (360-420 mm h-1) for 30 min, the untreated control had the highest soil loss (28.9 t ha-1). Separate and combined introductions of phosphogypsum and turkey litter significantly increased soil resistance to water erosion. Co-introduction of the amendments strengthened this effect especially when the phosphogypsum to turkey litter ratio increased from 1:10 to 1:2 at the higher dose (60 t ha-1). The turbidity of the runoff from a 1° slope reached a small peak within the first 3 min then gradually decreased thereafter. At 3°, the turbidity remained nearly constant over time and was uniformly distributed. At 7°, the turbidity sharply increased then gradually decreased and its distribution was a deformed bell. Washed-out (trapped) sediments from all treatments and slopes had relatively more very fine sand, silt, and clay and a slightly higher total organic carbon content than the original soil. Phosphogypsum and turkey litter wastes may be effective anti-erosion amendments and potential fertilizers because they increase flocculation, improve the structure, and enrich the organic matter and nutrient content of the soil. [ABSTRACT FROM AUTHOR]