What is the primary characteristic of very stable organic matter within the soil?

Very stable organic matter is often characterized by a long persistence in the soil due to its resistance to decomposition. When we refer to this organic matter as being "1000s of years old," it signifies that it has a significant half-life, often extending beyond centuries, allowing it to accumulate and persist in soil profiles over substantial geological time periods.

This stability results from the complex structure of stable organic matter, which includes humic substances that take much longer to break down compared to other forms of organic matter. Thus, very stable organic matter plays a crucial role in long-term soil health, enhancing soil fertility, water retention, and nutrient cycling over extended timescales. Understanding the longevity of such materials is essential for managing soil health and promoting sustainable agricultural practices.