RETURN TO THE CARBON CYCLE
Turf Grass Production and Stewardship
1. Turf grass is generally grown within a monoculture system, and
as such, has a delicately balanced ecosystem.
2. All too often, lawns have way too much phosphorus (P) and
potassium (K), and not nearly enough nitrogen (N).
3. Carbon-depleted soils cannot effectively hold nitrogen for the
length of time it takes roots to absorb it; thus, it runs off, dissolved in
water, or floats off in the wind as it gasifies.
4. Fertilizer programs worsen soil conditions because they do not
put back carbon, which feed microorganisms and keeps soil fluffy
and gas-permeable. Soils that are fluffy are said to have loft. Soils
that have loft are said to be gas-permeable. Gas-permeable simply
means that soils have an air exchange rate between the atmosphere
and the soil that is great enough to sustain microbial life below the
5. How well a soil breathes, i.e., how deeply and how thoroughly, is
a function of how much and what types of carbon are present.
Types of Carbon Present in Healthy Soils
1. Sugars created by plants through photosynthesis and exuded
through their roots feed the microbial life colonizing the roots of the
same plant. These are the "heart-pounding, thrill-a-minute,
makes-life-worth-living" forms of carbon that sustain the relationship
between plants and the beneficial microbes on their roots.
2. Carbohydrates, starches, and cellulose, which come from plants
or parts of plants that have died and fallen into the soil, are more
complex and enduring forms of carbon that not only serve as food
for the soil food web, but also provide structure.
3. Polysaccharides and lignins, the most durable of all the carbon
structures, along with other features of the soil, form the
foundation for "soil horizons."
4. These soil horizons represent different "divisions of labor,"
organizing themselves into different horizontal layers.
5. All the forms of carbon within the soil layers serve multiple
* They provide loft so that soil breathes and microorganisms get
* They attract, absorb, and hold water for plants and
* They attract, absorb, provide, and disperse minerals and
nutrients for microorganisms and plants.
* They provide surface area and structure for microbial activity
and plant root development.
6. The life of the soil is dependent on these four factors:
* Food-sugars, carbohydrates, amino acids, and other raw
* Structure and shelter