No abstract

In Uzbekistan, more than half of population lives in rural area, their well-being depends on quality of land and water resources availability. Quality of land is determined by ameliorative indicators: ground water depth level, ground water salt amount and salinity of soil. These factors do not appear naturally but rather due to the human activity. Inefficient irrigation and excessive consumption of irrigation water on irrigated land in Boyavut District of Syrdarya region of Uzbekistan within several decades have led to a salinization of soil. The primary objective of this article is determination of the level of salinity of soil for modelling spatial distribution of soil salinity throughout an irrigated land by using GIS technology. This technology is focused on automation of development and creation of ameliorative maps, while totally eliminating manual operations. Nowadays, ameliorative expedition specialists still create cadastral map using tracing paper over the marginal areas within irrigated lands based on their ameliorative conditions and by selecting from the three thematic maps and then selecting the poorest conditions of ameliorative indicators. The suggested technology is designed for professionals of cadastral subdivisions of regional ameliorative expeditions, who use the GIS-based software, such as ArcView 3.2. or ArcGIS 10x; their duties include creating of thematic maps based on salinity levels of irrigated lands. Exact coordinates of collection sites of soils samples (collected in 2018-2019) were determined using GPS. The Inverse Distance Weighting (IDW) interpolation method was applied to use that data to create ameliorative maps categorized by the salinity levels (non-saline, slightly saline, saline area and highly saline areas). Those maps were then analysed to develop procedures on how to improve ameliorative conditions of irrigated areas.

Soil salinity is an important global issue and especially on irrigated areas due to its great impact on a crop production system. Proper soil salinity mapping can improve land use management. The goal of this study was to improve the accuracy of soil salinity mapping with the two objectives (1) to evaluate different interpolation methods during soil salinity mapping and (2) to identify of differences in soil salinity assessments in irrigated land of Mirzaabad district which is most affected by salinity in Syrdarya province of Uzbekistan. Soil salinity data measured by EC meter was obtained from Syrdarya Hydromelioration Expedition. Different four interpolation methods such as Inverse Distance Weighted (IDW) with power 1, 2, and 3, and Kriging techniques were used for the generation continuous surface of soil salinity maps. The cross-Validation method with the assessment of Root Mean Square Errors (RMSE) shows that IDW with power 2 (IDW-2) most accurate. The maximum difference reached between IDW-2 and IDW-1 on the slightly saline area where the value decreased by 55% of the total irrigated land of the district. Minimum differences reached on IDW-3 on moderated saline class and higher than IDW-2 on 408.6 ha.

В статье приводятся данные об особенностях накопления и характере локализации Cd, Pb, Zn, Cu, Co и Mn в растениях кукурузы (Zea mays) и подсолнечника масличного (Helianthus annuus) в различных почвенно-климатических условиях Самарского Заволжья, подтверждающие, что уровень концентрации тяжелых металлов в биотипах, за исключением Со, не превышает ПДК.

В статье рассмотрены особенности аккумуляции тяжелых металлов растениями, произрастающими на черноземе южном, выявлены закономерности распределения этих токсикантов в надземных (вегетативных и генеративных) и подземных органах растений.