Spatial and In-Depth Distribution of Soil Salinity and Heavy Metals (Pb, Zn, Cd, Ni, Cu) in Arable Irrigated Soils in Southern Kazakhstan

Abstract

Most irrigated lands in the Republic of Kazakhstan are in its southern part, in the large deltas and ancient alluvial plains in the basins of the rivers Syr Darya and Ili. The combination of climatic features and anthropogenic pressures leads to increased salinity and contamination of cultivated soils in this region, resulting in a qualitative and quantitative decline in crop production. The study’s primary goal was to assess soil secondary salinity and selected heavy metals (Pb, Zn, Cd, Ni and Cu) contamination in irrigated arable soils. To identify the potential source of soil pollution, we compared the concentration of salt and heavy metals (both total and mobile forms) in different soil types in three depths of soil profiles obtained from irrigated cultivated and non-cultivated (abounded) territory in the Shauldara massif in the southern part of Kazakhstan. All studied soils are prone to secondary salinization with either a medium or high content of sum of salts with domination by Na+ among cations and by SO42− among anions. The soil contamination with heavy metals was low, and, in most cases, except for cadmium, it was below the limits developed for arable soils in most countries. Soil contamination with cadmium results from contamination of the water used for irrigation of farmland.

Ecological Risk and Pollution Assessment of Heavy Metals in Farmland Soil Profile with Consideration of Atmosphere Deposition in Central China

“…Similarly, two APMS sites displayed a significantly larger distance compared to the other APMS sites. The results from the in-depth distribution of HMs in southern Kazakhstan indicate the higher spatial distribution of HMs in surface soil [ 40 ]. Our clustering results also implied the relatively wider spatial distribution of HMs in farmland soil, especially in surface soil.…”

The Role of Hemicellulose in Cadmium Tolerance in Ramie (Boehmeria nivea (L.) Gaud.)

“…The supernatant was centrifuged at 12,000 rpm for 30 min at 4 °C to obtain the cell organelle fraction as the precipitate and a soluble fraction containing some membranes, such as Golgi complex, endoplasmic reticulum, vesicles, tonoplast, and plasmalemma. Next, the cell wall fraction, organelle fraction, and soluble fraction were independently digested using HNO 3 :HClO 4 (3:1, v / v ), and the total amounts of Cd were determined using a flame atomic absorption spectrometer [ 60 ].…”

Mapping of Cornfield Soil Salinity in Arid and Semi-Arid Regions

“…And in Kazakhstan, this direction is at an early stage and not a single operational system for remote monitoring of soil salinity has been identified. Studies of soil salinity, their mapping and monitoring are traditionally carried out on the basis of field surveys [Malawska et al, 2022]. These methods are time-consuming, costly and do not allow real-time monitoring of large areas.…”

“…In the Republic of Kazakhstan most of the irrigated lands is located in the southern part, in the large deltas and ancient alluvial plains of the Syr Darya river basin (SRB). With the rapidly population density growth has increased anthropogenic impact, and a combination of climatic features leads to increased salinity and pollution of irrigated soils in this region, resulting soil salinization has become the main restraint for a Mapping of Cornfield Soil Salinity in Arid and Semi-Arid Regions crop production and regional ecosystems [Suska-Malawska et al, 2022]. The Shaulder irrigated massif in the middle reaches of the Syr Darya river, where irrigated lands are most widely used for cornfields, the degree of soil salinity is different and it has been determined that they increase with depth [Laiskhanov et al, 2022].…”