The concentration of arsenic (As), considered a toxic and carcinogenic metalloid, in agricultural soils has become a global challenge. Sources of arsenic in soils can be both anthropogenic and natural. Contaminated water is used for the irrigation of crops and vegetables, and therefore it is the main pathway for arsenic to enter the human food chain, creating a potential health risk. This study evaluated the concentrations of arsenic in agricultural soils in the rural parish of Papallacta, located 67 km east of the city of Quito, Northeastern Ecuador, and constitutes an analysis of the problem of arsenic in agricultural soils. Shallow groundwater and geothermal water discharges laced with arsenic are frequently used for irrigation and have raised the level of arsenic in agricultural soils. This work is focused on evaluating the environmental quality and contamination of agricultural soils through environmental quality indices such as geo-accumulation index, enrichment, and contamination factor. The average arsenic levels in the agricultural soils of the four studied areas fluctuate between 20.4 and 43.0 mg kg⁻¹, while in the sediments of the Papallacta Lake, higher values were found in the range between 16.8 and 102.4 mg kg⁻¹; all of which exceed the permissible limit by the Ecuadorian Environmental Legislation for agricultural use (12 mg kg⁻¹). The results of the study in the five studied sites of the Papallacta civil parish indicate low to moderate levels of arsenic enrichment, soils enriched by bedrock, and moderate to considerable contamination.

Soil erosion affects land productivity, water quality, and ecosystem resilience. Traditional monitoring methods are often time-consuming, labor-intensive, and resource-demanding, while unmanned aerial vehicles (UAVs) provide high-resolution, near-real-time data, improving accuracy. This study conducts a bibliometric analysis of UAV-based soil erosion research to explore trends, technologies, and challenges. A systematic review of Web of Science and Scopus articles identified 473 relevant studies after filtering for terms that refer to types of soil erosion. Analysis using R’s bibliometrix package shows research is concentrated in Asia, Europe, and the Americas, with 304 publications following a surge. Multi-rotor UAVs with RGB sensors are the most common. Gully erosion is the most studied form of the issue, followed by landslides, rills, and interrill and piping erosion. Significant gaps remain in rill and interrill erosion research. The integration of UAVs with satellite data, laser surveys, and soil properties is limited but crucial. While challenges such as data accuracy and integration persist, UAVs offer cost-effective, near-real-time monitoring capabilities, enabling rapid responses to erosion changes. Future work should focus on multi-source data fusion to enhance conservation strategies.

Olive groves (Olea europaea L.) are highly susceptible to soil degradation, particularly water erosion, due to sparse canopy cover and wide inter-row spacing. This study evaluated the effect of different vegetation cover management practices on soil quality and erosion control in a tropical olive grove in southeastern Brazil. The experiment followed a randomized block design with five treatments: exposed soil (BS), olive trees on exposed soil (OB), olive trees with spontaneous vegetation managed with herbicide (OVH), with mowing (OVM), and with mowing + localized weeding (OVMC). Physical, chemical, and biological indicators and losses due to water erosion were analyzed. The OVM and OVMC treatments promoted an increase in soil organic matter (up to 39 g kg⁻¹), microbial biomass carbon (40% higher than BS), enzymatic activity, and glomalin, improving aggregate stability (WMD of 4.9 mm) and reducing soil and water losses by more than 99% compared to exposed soil. The BS and OB treatments, on the other hand, showed higher acidity, lower microbial activity, and greater susceptibility to erosion. The study reinforces that maintaining vegetation cover improves soil quality, mitigates erosion, and promotes the sustainability of olive groves in tropical regions.