Just as I promised there will be more discussion on turf grass selection this month. However, now is an excellent time to explore the fundamentals of soil structure and function as it pertains to turf grass production. Understanding these things will lead us directly to the satisfaction and bliss that comes from that sea of green turf grass that we grow ourselves.
Any turf grass can be considered as a crop, and, as such, requires real fertility to overcome weeds and to be able to handle environmental stresses such as too hot, too cold, too wet, too dry, too much foot traffic etc. Consider the fertility factor of “loft.” Loft is how fluffy a soil is. How fluffy it is, is a factor of how easy it is for a grass to grow its roots and runners through it. Loft is also a factor of how easily a soil will absorb water, as opposed to it running off into the creek along with the fine particles of your remaining topsoil. Loft is also a factor of how soil breathes. That’s right, you read it right, how soil breathes. Soil breathes? How does it do that, and why is that necessary? The microbial life in the soil, the ones that live in symbiosis with the grass roots (and many others) are air-breathing microbes. They must have a fresh supply of oxygen to digest carbon for energy and do the work of transporting water, foods, and minerals into the plant’s root system. If the available oxygen is limited, the work the microbes do is also limited. For the plants (turf grass in this case) the limited microbial activity means less water, nitrogen, trace minerals, phosphorous, calcium, and all the rest. The plants growth slows down, it loses its vigor. Weeds, pests, and pathogens can and will take advantage of this. Oxygen rich soils counter all this mayhem and make your lawn healthy and strong.
So how does this fluffy soil breathe you ask, having never seen it heave up and down, at least not while you were looking. It breathes, so to speak, with changes in barometric pressure, even minute changes. This is what pumps air into and out of the soil. Oxygen is not the only gas going in and out of the soil; there is also nitrogen, and that’s free nitrogen for your crop or turf grass. There are microbes not associated with legumes that also fix nitrogen into the soil and make it available to plants. These are called azotbactor microbes.
This one factor referred to as soil loft is probably the most unsung hero of soil fertility. Next month more on turf grass selection.