Winter’s Effect On Spring Growth: Measuring Total Organic-C

Winter snow melting

In soil, organic carbon is the primary energy source for microorganisms, and it triggers nutrient availability for plant growth. The total organic-C (TOC) in soil affects color, nutrient capacity (cation and anion exchange capacity- CEC), nutrient stability and turnover, water relationships, aeration, cultivation, and plant growth and health. In the Winter season, snow cover insulates and protects soil from deep frost. Deep frost can injure plant roots, alter the activity of the soil decomposer community, and cause problems with the TOC composition of the soil. Abiotic factors, including global climate change and snow management processes by humans, alter the snowpack and influence the dissolution and mineralization of TOC. These changes in the soil composition in Winter can have dire effects on ecosystem processes during the Spring growing season.

Measuring TOC provides information on soil fertility, aggregate stability, and the exchange of CO2 with the atmosphere. These characteristics are vital for ecological applications, including environmental monitoring and precision agriculture. Soil analysis is typically performed in a lab and is destructive, time-consuming, and costly. UV-Vis-NIR spectroscopy offers a fast, accurate, and affordable alternative to lab analysis. Various components within a sample each have unique spectral signatures defined by reflectance or absorption as a function of wavelength. Researchers can use field spectrometers and spectroradiometers to collect spectra and measure properties, including TOC, in situ without altering or damaging a sample. Typical soil samples show TOC features between 400-570nm, 1434-1476nm, and 1819-2001nm.

Soil conditions impact not only our planet's ecosystem but also human infrastructure. Snow cover, or lack thereof, may significantly alter soil composition affecting food and other resources. Our Earth is in a delicate state, and scientists must utilize non-destructive alternatives for testing and research. High-resolution spectrometers, like the Spectral Evolution NaturaSpec™, allow users to collect lab-quality spectral scans in the field without sample preparation. The collected data provides a highly accurate analysis of soil composition, which can be quantitatively correlated to TOC. These rugged, battery-operated instruments utilize solid-state photodiode array detectors with no moving optical parts to ensure toughness and provide excellent stability and repeatability of measurement.