The chemical reinforcement of sandy soils is usually carried out to improve their properties and meet specific engineering requirements. Nevertheless, conventional reinforcement agents are often expensive; the process is energy-intensive and causes serious environmental issues. Therefore, developing a cost-effective, room-temperature-based method that uses recyclable chemicals is necessary. In the current study, poly (styrene-co-methyl methacrylate) (PS-PMMA) is used as a stabilizer to reinforce sandy soil. The copolymer-reinforced sand samples were prepared using the one-step bulk polymerization method at room temperature. The mechanical strength of the copolymer-reinforced sand samples depends on the ratio of the PS-PMMA copolymer to the sand. The higher the copolymer-to-sand ratio, the higher the sample’s compressive strength. The sand (70 wt.%)-PS-PMMA (30 wt.%) sample exhibited the highest compressive strength of 1900 psi. The copolymer matrix enwraps the sand particles to form a stable structure with high compressive strengths.

Knowledge of the presence of heavy metals in soils of agricultural areas is important to prevent their accumulation in cultivated plants. The objective of the present investigation was to evaluate the total concentrations and fractions of heavy metals Cd, Pb, Zn, Fe, Mn, Ni, Cu, Cr and Co in the tobacco-growing area of Pinar del Río, Cuba and their relationship with the physicochemical properties of soil. For the study, 59 samples of three types of soils were collected at 20 cm depth. The pseudo-total concentrations of metals in the soils are low and lower than the prevention values registered for Cuban soils. In general, the heavy metals studied present a high affinity for the most stable fractions of the soil, which means a low risk of transfer to the tobacco crop or accumulation in groundwater. The pseudo-total concentrations of heavy metals were low, below the alert values established for soils in the region. The heavy metals studied were mainly associated with the residual fraction, the second fraction with the highest association with metals was that linked to manganese and iron oxides. The principal component analysis showed that their main source is pedogenetic and that these elements are closely related to cation exchange capacity and calcium content.

This study investigates the impact of extreme rainfall events on soil erosion in the downstream Parnaíba River Basin, located in the Brazilian Cerrado. The analysis focused on rainfall erosivity (R factor) and soil erodibility (K factor) as key indicators. The average erosivity in the region was 9051 MJ mm h⁻¹ha⁻¹year⁻¹, with a variation between 7943 and 10,081 MJ mm h⁻¹ha⁻¹year⁻¹, suggesting a high erosive potential, mainly in the rainiest months, from December to April. The soils of the studied area, mainly Ultisols and Chernosols, present high to very high erodibility, with K factor values ranging from 0.025 to 0.050 t h MJ⁻¹ mm⁻¹. Furthermore, fieldwork revealed areas, near highways, with apparently fragile soils, as well as rills and gullies, identified through photographs taken during fieldwork. These locations, due to the combination of high erosivity and susceptible soils, were considered prone to the occurrence of erosion processes, representing an additional risk to local infrastructure. The spatialization of R and K factors, along with field observations, showed that much of the area is at high risk of erosion and landslides, particularly in regions with greater topographic variability and proximity to water bodies. These results provide a basis for the development of mitigation strategies, being important for the effective prevention of landslides.

Afforestation is a main tool for preventing desertification and soil erosion in arid and semiarid regions of Iran. Large-scale afforestation, however, has poorly understood consequences for the future ecosystems in the term of ecosystems protection. The objective of the present study is to identify changes in soil properties following different intervals of planting of Ailanthus altissima (tree of heaven) in semiarid afforestation of Iran (Chitgar Forest Park, Tehran). For this purpose, sand, silt and clay ratios, bulk density, soil moisture, pH, electrical conductivity, phosphorus, potassium, magnesium, calcium, sodium, total soil N, and total carbon was measured. Our study highlighted the potential of the invasive trees by A. altissima, to alter soil properties along chronosequence. Almost all soil quality attributes showed a declining trend with stand age. A continuous decline in soil quality indicated that the present land management may not be sustainable. Therefore, an improved management practice is imperative to sustain soil quality and maintain long-term productivity of plantation forests. Thinning activity will be required to reduce the number of trees competing for the same nutrients especially in a older stand to protect forest soils.

Heavy metal contaminated soil due to industrial, agricultural and municipal activities is becoming a global concern. Heavy metals severely affect plants, animals and human health. A suitable technology is necessary for heavy metals removal because it cannot self-decomposition as organic compounds. Among the various technologies surveyed, phytoremediation is one of the safest, most innovative, environmental friendly and cost-effective approach for heavy metals removal. Nevertheless, traditional phytoremediation practices pose some limitations such as long processing time, unstable treatment efficiency and limited application at large scale. In many methods proposed to improve phytoremediation, integrated phytoremediation has been studied in the recent years. Integrated phytoremediation use chelating agents and phytohormones to enhance phytoremediation. This is an environmentally safe, saving time and relative high effective method. Results showed that the association of a metal ion and a chelating agent to form chelates helps to maintain the availability of metals in the soil for the uptake of plants. Phytohormones supply nutrients for the soil to support vegetable growth. Therefore, integrated phytoremediation is a promising solution to overcome the disadvantages of conventional phytoremediation. It should be taken commercialization and need more applied projects in this field to demonstrate and clarify the real potential of this technology. In view of above, this manuscript reviews the mechanism and the efficiency of integrated phytoremediation for heavy metals in contaminated soil to give an overview of this technology.

A Detailed geophysical investigation was conducted on Knossos territory of Crete Island. Main scope was the detection of underground archaeological settlements. Geophysical prospecting applied by an experienced geophysical team. According to area dimensions in relation to geological and structural conditions, the team designed specific geophysical techniques, by adopted non-catastrophic methods. Three different types of geophysical techniques performed gradually. Geophysical investigation consisted of the application of geoelectric mapping and geomagnetic prospecting. Electric mapping focusses on recording soil resistance distribution. Geomagnetic survey was performed by using two different types of magnetometers. Firstly, recorded distribution of geomagnetic intensity and secondly alteration of vertical gradient. Measured stations laid along the south-north axis with intervals equal to one meter. Both magnetometers were adjusted on a quiet magnetic station. Values were stored in files readable by geophysical interpretation software in XYZ format. Oasis Montaj was adopted for interpretation of measured physical properties distribution. Interpretation results were illustrated as color scale maps. Further processing applied on magnetic measurements. Results are confirmed by overlaying results from three different techniques. Geoelectric mapping contributed to detection of a few archaeological targets. Most of them were recorded by geomagnetic technique. Total intensity aimed to report the existence of magnetized bodies. Vertical gradient detected subsurface targets with clearly geometrical characteristics.