Soil organic matter (SOM) is a key factor in the carbon cycle and climate change mitigation, but its distribution and characteristics in different forest ecosystems require more insights. This study compared the SOM profiles of two forest soils in Spain, using infrared spectroscopy and color measurements. Results showed that vegetation type, soil profile depth and other factors influence SOM content and quality while the color of humic substances reflected the degree of oxidation and stabilization of organic matter.

It is important to accurately assess soil phosphorus levels in order to ensure optimal crop growth, particularly in tropical regions where phosphorus availability is limited. Our research findings indicate that the resin extraction method is a more effective approach than other methods for determining the available phosphorus content across a range of soil types and for diverse phosphate fertiliser sources. This development provides farmers and agronomists with enhanced resources to optimise fertiliser utilisation, thereby promoting enhanced crop yields and sustainable agricultural practices.

The interplay of lithology and soil properties is closely linked with climatic variables, warranting investigations at a regional scale. The majority of existing studies on soil clay mineralogy did not include information on the mineralogy of the weathered parent rock, which hinders a comprehensive understanding of the effects of lithology on soil clay mineralogy. A comparison between the mineralogical composition of rock weathering rinds and soil clay fractions reveals a trend of chlorite degradation.