Thirty years of compost: more carbon and changes in soil life
Regenerative News · Research published on 30 September 2026
Regular compost applications can leave a lasting mark on soil. A new study of a thirty-year experiment in China examines organic carbon, nutrients, and bacterial and fungal communities together.
What the researchers compared
In a winter wheat–summer maize rotation, the researchers compared two application rates of conventional compost and microbially enriched compost with soil receiving no amendments.
The compost was made from plant residues and manure. For the enriched version, a mixture of selected microorganisms was added before composting.
More carbon and greater microbial activity
Compost applications were associated with:
- Higher concentrations of organic carbon and nutrients.
- Greater activity of enzymes involved in breaking down organic materials.
- Changes in the composition of bacterial and fungal communities.
At the higher rate of enriched compost, organic carbon concentration was 33.8% higher than in the untreated control. The greatest bacterial diversity was recorded at the lower rate of the same compost: the amount and composition of the material affected microbial groups differently.
Compost quality can also be assessed under the microscope
In the approach taught by Dr. Elaine Ingham’s Soil Food Web School, we examine which organisms we introduce into the soil. Biologically complete compost includes bacteria, fungi, protozoa and beneficial nematodes. Microscopic observation helps us identify these groups and assess the material’s microbiology.
Connection with our field work
At our Center, we produce different compost piles and monitor their microbiology under the microscope, following our training at the Soil Food Web School. We select compost and its liquid derivatives according to the needs of the soil and crop.