Particulate Organic Matter

Relationship to Soil Function
As perhaps the most easily decomposable fraction of nonliving SOM after microbial biomass, POM fulfills many soil functions mediated by OM. It is a source of food/energy for microorganisms and soil animals as well as nutrients for plant growth. Particulate organic matter enhances aggregate stability, water infiltration and soil aeration; it increases cation exchange capacity and buffering pH. It also binds environmental pollutants such as heavy metals and pesticides. Particulate organic matter may play an important role in the suppression of soil borne diseases (e.g. damping off of cucumber) by compost. This may be explained by the fact that POM is an important source of food/energy in the compost for microorganisms responsible of disease suppression.
POM and Poor Soil Function
In poorly managed soils, the transport by erosion of sediments rich in POM into rivers and other water bodies can result in alteration of water quality and aquatic life. Build up and mineralization of those organic materials lead to the eutrophication of lakes and rivers. Incomplete mineralization of POM C in very poorly drained soils can lead to the formation of methane, which escapes into the atmosphere and contributes to ozone depletion.
Improving POM Levels
Management that affects SOM accumulation also affects POM content in soil (figs 2 and 3). More POM in the soil means that carbon and other nutrients are being stored in the intermediately available pool and are not subjected to losses (e.g., leaching) yet are available when needed.
The following practices enhance POM levels:
- Tillage management (no-till, strip till, and ridge till)
- Crop rotation, cover crops, and cropping frequency (reduction in fallow frequency)
- Application of manure/compost and organic byproducts
- Pasture and hay land management (e.g., rotational grazing and haying)
This Page Was Created Utilizing Text And Images From These Sources:

2023 Soil Health School Registration Open!
The 2023 Soil Health School will be held August 28-30 on the farms of Anthony Bly and Bruce Carlson near Garretson, SD! There will be classroom sessions, field excercises, discussion panels, and opportunities to network with researchers, industry professionals, and experienced producers who can help you on your soil health journey! Class size is limited, so learn more and register today!
News & Events
Long-term research reveals advantages of diverse crop rotations
By Stan Wise PIERRE, SD – It can take time for scientists to build new knowledge of biological processes, especially when those processes play out over the course of years. Researchers with the U.S. Department of Agriculture-Agricultural Research Service North Central...
‘Park the chisel’: First step toward soil health can be simple
By Stan Wise PIERRE, SD – The benefits of improved soil health for agricultural producers and gardeners are numerous and valuable – reduced input costs, improved profitability, drought and flood resilience, reduced erosion, improved water quality, increased wildlife...
Saline Soil Management: More Money With Fewer Crop Acres
By Stan Wise PIERRE, SD – Salinity areas. Trouble spots. White deserts. Regardless of what they’re called, saline soils are a problem for South Dakota. White, salty areas where nothing grows are a common sight in fields across the state. “The amount of salinity that's...