Soil is the foundation for global food production and is involved in a number of critical environmental and biological processes. With a strong link between soil, geology, and life sciences, there is a wide range of techniques that can be used to understand soil composition and properties.
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Soil serves as a habitat for plants and microorganisms, regulates the hydrological cycle, and mitigates climate change through carbon sequestration. At the same time, soil can also be a reservoir for a large number of pathogens that are often introduced via contact with contaminated water.
Introduction
Soil conditions and properties result directly from its composition. Therefore, knowing the chemical and biological content through advanced soil analysis and monitoring of the soil condition is of great importance not only for its sustainable and optimal maintenance but also for evaluating environmental health, progress of degradation, and remediation.
Geological analysis plays a vital role in life sciences by identifying hazards and aiding the sustainable management of ecosystems. For instance, the mapping of underground aquifers can allow the responsible use of water resources, maintaining ecological balance and supporting biodiversity.
The analysis of soil contaminants (e.g., hydrocarbons, pesticides, heavy metals) and the determination of soil quality by measuring organic content and nutrients can provide insights into the soil and its productivity, as well as potential risks to human health.
This article delves into the latest advancements in soil and geology analysis, covering some of the main analytical techniques and drawing on insights from interdisciplinary research in life sciences.
Emerging Techniques in Soil Analysis
Spectroscopy has a pivotal role in advanced soil analysis. It is frequently used to map the type of soil and to study its properties and conditions by identifying and quantifying components based on spectral signatures. Some devices can also be installed on drones, balloons, and satellites, thus enabling remote or even orbital sampling.
Mid-infrared (MIR) spectroscopy utilizes radiation in the range of 2500-25,000 nm, which interacts with fundamental vibrations of organic molecules containing soil organic carbon and nitrogen, as well as minerals in clays and sand, and it is commonly used in advanced soil analysis. Visible and near-infrared (NIR) spectroscopy (780-2500 nm) is often used to assess many physicochemical properties that reflect the conditions of soil and its composition.
Inductively coupled plasma-mass spectrometry (ICP-MS) allows rapid elemental and isotopic analysis with high sensitivity, whilst advances in laser-induced breakdown spectroscopy (LIBS) have reduced the size of instruments, leading to handheld devices for field analysis of soils and geological materials.
X-ray fluorescence spectrometry (XRF) is a non-destructive technique that can detect elements from Na to U, and it is frequently used for the analysis of rocks, ores, and soil. The monitoring of heavy metals in soils via XRF is well-established, although there is also potential to use XRF to estimate sand and clay contents as well as soil organic matter.
Geological Analysis: Unveiling the Secrets Beneath
Geological analysis is important to biology and ecology, and it is crucial for managing water resources and identifying potential areas for biodiversity conservation.
A geological survey is the systematic investigation of the geology underneath a given piece of ground with the aim of creating a map or model. Geological survey techniques include remote sensing, satellite imaging, LiDAR, and ground-penetrating radar, providing detailed insights into the soil structure.
Ground-penetrating radar (GPR) is a non-invasive method that uses radar pulses to image subsurface structures. GPR supports groundwater exploration and monitoring and contributes to land-use planning, infrastructure development, and archaeological research.
LiDAR (Light Detection and Ranging) is an airborne laser scanning technique that provides detailed topographic information. The technique maps fault lines, landslides, and volcanic craters and is used in forestry, flood modeling, and habitat assessment.
Case Studies: Real-World Applications in Life Sciences
In 2013, a long-term monitoring program was launched – the Saxon Permanent Monitoring Soil Program – aiming at monitoring via NIR and MIR spectroscopy techniques a large number of parameters in a German region with a long mining history.
The aim of the program was to evaluate changes in soil properties over time, assess the pollution levels, and identify pollution sources, with a focus on monitoring the content of several metals and metalloids (i.e., As, Cu, Fe, Mn, Ni, Pb, and Zn), total organic carbon, and soil pH.
The impact of soil pollution on human health has been extensively investigated. Most of the studies focus on heavy metals, aiming to assess the degree of soil contamination and exposure risks for humans. Appropriate mapping of soil heavy metal contamination in urban, industrial, and agricultural areas is a crucial aspect.
In particular, the identification of spatial patterns can help understand the sources of pollution, the factors that govern soil pollution distribution, and the population exposed to soil contamination.
Challenges and Future Perspectives
The complexity of soil and geology systems can make it difficult to interpret the analysis results since it requires expertise in both soil science and life sciences. Current challenges include the need for interdisciplinary research, data integration, and technological accessibility.
However, ongoing technological advances in remote sensing, machine learning, and sensor networks, together with increased collaboration between scientists, hold the potential to overcome such challenges.
Conclusion
From enhancing agricultural practices to safeguarding environmental health, soil and geology analysis techniques are integral to the life sciences. The advances in geological survey techniques and other analytical methods, together with the interdisciplinary nature of the field, highlight the need for collaborative efforts to understand better and manage ecosystems, support agriculture, assess environmental impact, and safeguard human and environmental health.
Sources
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Further Reading