Biogeochemical State of Salinized Irrigated Soils of Central Fergana (Uzbekistan, Central Asia)

The Central Fergana region is one of the overpopulated regions Asia, which includes parts Uzbekistan, Kyrgyzstan, and Tajikistan. Here, in dry subtropical climate are most ancient, irrigated oases used for agriculture. valley key to food security as a whole. article provides information on diversity chemical composition newly developed, new old-irrigated Calcisols soils formed alluvial alluvial–prolluvial sediments. Soils poor with organic matter (0.37–0.81% carbon), high nitrogen content (C/N ratio 4.92–5.79), neutral (7.01–7.30) pH values. Data components soil salinity (Na2CO3, Ca(HCO3)2, CaSO4, MgSO4, Na2SO4, NaCl) bulk salts under different irrigation regimes presented. It was shown that Na2CO3 concentration minimal all soils, this salt presents only ground waters (0.100–0.135 g L−1). Newly characterized by higher than old soils. All investigated increasing rate within depth highest waters. This chloride–sulfate type salinization pronounced studied. Gypsum agricultural results limited water nutrient retention potential dissolution, primarily response irrigation. Valley also subjected polychemical pollution, so trace elements them Irrigated meadow-takyr meadow-saz show low levels environmental hazard, but accumulation such nickel (30 mg kg−1), arsenic (11.75 bromine (5.00 antimony (1.48 cesium hafnium (2.97 kg−1). Irrigation affects texture thus increases fine particle percentages superficial horizons. Thus, complex characteristics salinized presented numerous landscapes region.