John Ossa: The meaning of green

John Ossa

Through use, we have come to know what “green” signifies.  We equate it with “sustainable,” another amorphous term that lacks specificity. What these terms hope to capture are “ecological practices,” which begin to describe science-based actions that don’t undermine the biologically diverse and interdependent plant and animal communities.

In our rush to embrace “green,” it is surprising how often basic truths are devalued or ignored in order to support the notion of the day. For example, all over the U.S. we see green roofs being installed.  Building on experience from countries like Germany, where green roofs are not unusual, they are being installed because of their significant benefit to improving surface water quality by trapping and holding water, reducing excess runoff, and reducing the high temperatures associated with synthetic, static surfaces.

Yet many of the same people that promote green roofs also promote ripping out turf playing fields and installing synthetic playing surfaces. The fibrous root systems of turf catch and filter polluted runoff water. Turf root systems are efficient at controlling soil erosion and increase groundwater recharge. Turf grass reduces atmospheric carbon dioxide and releases oxygen. How much oxygen does the ground up car tires that make up a synthetic playing field release?

More ironic is the desire to reduce the “heat island” effect in the urban environment through installing green roofs, yet the “heat island” over something as large as a soccer field is discounted.  There is plenty of data about extremely high surface temperatures of synthetic turf – in fact a study done at BYU documented average synthetic field surface temperature is more than 40 degrees higher than turf, and routinely more than 100 degrees.  So why is the “heat island” from something the size of a football field, somehow different from the “heat island” over a rooftop?

A way forward is to set the objectives and let the free market economy solve the problems. For example, turf playing fields have been justifiably criticized for high water use. There are new irrigation delivery systems that are far more efficient than conventional rotor systems. These next generation sub-surface systems deliver water reliably and uniformly through a geotextile membrane, and create an optimum soil moisture environment using far less water than conventional hardware of any type.

There are extreme examples of fertilizer applications on playing fields creating pollution or contamination of watersheds. Again, the free market is solving the problem. Manufacturers are developing slow release products and a whole awareness regarding the benefits of building a diverse and healthy soil biology as a key strategy in sustaining turf are being implemented. This combined with subsurface fertigation that does not run-off, are solving the problem.

Instead of knee-jerk measures equating removing turf as a step toward “sustainability,” let’s support clear goals for sustaining biological diversity, ecological practices and the new science based technologies that deliver the real green – real environmental benefits – real photosynthesis producing real oxygen. 

John Ossa owns Irrigation Essentials, a web-based irrigation consulting firm. See www.irrigationessentials.com; mail ossa@gie.net.