SRA Research Project Final report UV absorption as a tool for growers to benchmark humified organic carbon in soil

Abstract

In this project, we investigated the feasibility of modifying well established methods for quantifying aquatic humic substances, for detecting soil humic substances. Soil humic substances are the dark coloured, organic compounds that stain the soil below the litter layer, distinguishing ‘topsoil’ from dirt. Soil humic substances are the by-products of organic matter repeatedly attacked by soil microbes, becoming more complex and resilient over time. Standard water quality methods for measuring dissolved organic carbon (DOC), aquatic humic substances (the fraction of DOC absorbing ultra violet light; UV253.7), and specific UV absorbance (UV253.7 divided by DOC) were adapted for measuring soil humic substances.