We talk a lot in sports turf management about U.S. latitude zones and the basic grass types we cultivate in them. You know, the cool-season zone, the warm-season zone and the transition zone that run laterally across the country and are based mostly on temperature and day lengths. We talk much less about longitudinal zones, or east versus west.
If you look at the U.S. from space (e.g. Google Earth), you’ll generally see a green tint on the eastern half of the country and a brown tint on the western half, except for the high mountainous areas and the far West Coast (much of that is due to agricultural irrigation). The general demarcation line is about western Kansas, or central Nebraska. This is where you find the 100th meridian, which runs north-south right down the east side of the Texas Panhandle.
The 100th meridian was where the great 19th-century surveyor and explorer John Wesley Powell, father of the United States Geological Survey, realized that few crops can grow west of without supplemental irrigation. He tried to impress this discovery upon government leaders — who still subscribed to the discredited “rain follows the plow” theory of climatology — and showed them how the basic model being used back East for homesteading, water rights and pioneering wouldn’t work out West. However, legislature did not heed Powell’s clarion calls until after the Dust Bowl era of the 1930s, and scores of homesteaders suffered miserably as the result of this congressional ignorance.
As I ask myself in all matters of life, what does all this mean to the sports field manager? The 100th meridian stands as a reminder that U.S. turfgrass management isn’t just different north to south, but also east to west, and a well-rounded turf manager would do well to realize this in their education and experiences, with some obvious exceptions:
Turfgrass managers back East tend to understand drainage better than irrigation. It’s the exact opposite out West. The truth is, when it comes to quality sports fields, both are equally important. Western sports field managers are sometimes surprised to hear that many playing fields back East don’t have irrigation systems. The 100th meridian is a general demarcation line for 20 inches of annual precipitation, roughly the minimum for most cultivated crops, including turfgrasses. Eastern field managers may be surprised when they hear that many sports fields out West don’t have internal drainage systems, as they rely on surface drainage alone: ‘A percent and a half and we’re good to go!’
Soils weather and leach differently in the East when compared to the West. Eons of this annual east-west precipitation gradient, among other factors, has created two Americas in terms of soils. Out West, we tend to generally see higher pHs, finer textures, lower percolation rates, higher salinities and a lower organic content. Fresh surface water resources tend to naturally be of lower quality in the West. This kind of soil management may be the greatest of all differences to the sports field manager.
Drier air generally means less disease pressure, as most turfgrass fungal pathogens need a moist environment to establish themselves. The turfgrass manager that cuts their turfgrass teeth back East will enjoy coming out West and not having to scout, nor spray, nearly as much. When we Western turfies see some mycelium, we instinctively say, ‘Cool, let’s see if we can get it to spread!’ (tongues fully in cheeks).
Powell correctly identified what we might call a precipitation transition zone just east of the 100th meridian, where a field manager may be good most years without supplemental irrigation, but wiped out in the inevitable droughts if they lack an irrigation system. It strikes me that if you overlay the two important turfgrass transitional zones on a map, then eastern Kansas sports field managers are the most naturally challenged of all. Hello, Wichita, Kansas!
I would suggest that any turfgrass scientist or sports field manager read Wallace Stegner’s “Beyond the Hundredth Meridian: John Wesley Powell and the Second Opening of the West” (1954). It still holds up, as do many of Wesley Powell’s dire warnings. Keep in mind, this dry-moist turfgrass climate divide will likely gain importance in future years.